CA3151822A1

CA3151822A1 - Method for separating solids from a tailings slurry

Info

Publication number: CA3151822A1
Application number: CA3151822A
Authority: CA
Inventors: Martin David Powell; Julia HOFINGER; Mitchell Louis Catling; Coralys TORRES LOPEZ
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2021-03-16
Filing date: 2022-03-14
Publication date: 2022-09-16

Abstract

The invention relates to a method for separating solids from a tailings slurry that has a solids content of from 25 to 70% by weight and comprises sand particles and fines particles with a sand to fines ratio (SFR) of from 0.5:1 to 5:1, in which the fines particles comprise clay. The method involves adding to the tailings slurry a clay decoagulant reagent (DGR) and a flocculent. The method comprises at least one first mass flow (MS1) of the tailings slurry (TS) which flows to at least one first mixing region (MRI) containing at least one agitation means (AGI), optionally at least one second mass flow (MS2) flowing the tailings slurry (TS) from the at least one first mixing region (MRI) to at least one second mixing region (MR2) containing at least one agitation means (AG2). The tailings slurry (TS) is flowed from the at least one first mixing region (MRI) and/or optionally at least one second mixing region (MR2) as at least one conditioned tailings stream (CTR) which is separated into a solids rich phase and a solids depleted liquor. The method is controlled by of at least one item of information (11) associated with at least one first mass flow (MS1) and is directly or indirectly selected from the group consisting of the sand to fines ratio (SFR); the solids content; the specific gravity; the clay content and the flow rate of the tailings slurry (TS) in the at least one first mass flow (MS1), optionally at least one item of information (13) associated with fluidity measurements (FM1) showing any change in fluidity of the tailings slurry (TS) in the at least one first mixing region (MRI), optionally at least one item of information (14) associated with fluidity measurements (FM2) showing any change in fluidity of the tailings slurry (TS) in the at least one second mixing region (MR2), at least one item of information (15) associated with (15a) the at least one conditioned tailings stream (CTR); and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated therefrom, wherein (15a) is associated with changes to the structure of the conditioned tailings stream (CTR) and (I5b) is associated with changes in at least one of the group selected from solids/liquid separation rate; volume of released liquid; turbidity of released liquid; and moisture content of separated solids.

Description

BASF SE

Method for separating solids from a tailings slurry Field of the Invention The invention relates to a method for separating solids from a tailings slurry that has a solids content of from 25 to 70% by weight and comprises sand particles and fines particles with a sand to fines ratio (SFR) of from 0.5:1 to 5:1, in which the fines particles comprise clay. The method involves adding to the tailings slurry a clay decoagulant reagent (DGR) and a flocculent.
Background of the Invention Processes of treating mineral ores, coal or oil sands to extract mineral values or in the case of coal and oil sands to recover the hydrocarbons, will normally result in waste material from the beneficiation process. Often the waste material is an aqueous slurry or sludge comprising particulate mineral material, for instance clay, shale, sand, grit, oil sands tailings, metal oxides etc. admixed with water.
Typically, the slurry of waste material would be thickened in one or more gravity sedimentation vessels, which are sometimes referred to as thickeners, to concentrate the solids and recover some of the water content. In some processes where the valuable metal is recovered by dissolution or leaching, the waste solid material may be separated from the liquor containing the mineral values by a series of counter current sedimentation vessels, sometimes referred to as a recovery circuit. In the Bayer alumina process for example, following an initial digestion stage, the solids, often referred to as red mud, would be passed to an initial gravity sedimentation vessel, often referred to as a thickener, and washed in the liquor from subsequent gravity sedimentation vessels, often referred to as washer vessels.
The solids from the initial thickener stage would be passed from the base of the vessel as an underflow and into the first of a series of counter current sedimentation vessels (washer .. vessels), in which the solids from each washer vessel would be passed as an underflow successively to each subsequent washer vessel and in which an aqueous liquor is used to wash the solids in each stage before being passed to each previous washer stage and then finally into the first thickener stage. Polymeric flocculants may be added into any one or more thickener or water stages to assist with the solids liquid separation.
The waste solids .. from the last washer stage would then be passed as an underflow to a disposal area, for example a lake usually referred to as a tailings pond or tailings dam.

Date Recue/Date Received 2022-03-14 BASF SE

GB 2080272 describes aqueous suspensions of red mud being removed from the Bayer process for making alumina by the addition of at least the first stage of the recovery circuit of a flocculants selected from starch, homopolymers of acrylic acid or acrylates, copolymers of acrylic acid or acrylates containing at least 80 molar percent acrylic acid or acrylate monomers and combinations thereof and subsequent addition to later, more dilute stages in the recovery circuit of a copolymer containing from about 35 to 75 molar percent of acrylic acid or acrylate and from about 65 to 25 molar percent of acrylamide monomers.
US 10889512 B2 describes the treatment of mine tailings in the form of aqueous effluents comprising solid particles. It is indicated that it is possible to separate or part of the water from an aqueous effluents comprising solid particles. This method is described as comprising (a) the addition of at least one sulphonated dispersing agent to the effluent, then (b) adding at least one flocculating agent to flocculate the solid particles.
This document also describes a composition comprising an aqueous effluent that contains dispersed, flocculated .. solid particles.
US 5653946 refers to a process for fluidifying flocculated aqueous suspensions of red muds in the production of alumina from bauxite by the Bayer process, which consists: in dissolving bauxite using sodium hydroxide; then, in decanting and in washing the red muds formed in order to separate them from the alumina in successive vats, while recycling the washing water upstream; and finally, in eliminating the red muds thus treated; and in which a flocculent consisting of a polyacrylamide of molecular weight greater than 10 million is introduced into the suspension of one of the successive vats; wherein a dispersing agent formed by an anionic acrylic acid polymer of molecular weight lower than 50,000 is added simultaneously with said flocculent to the suspension in the same vat.
In a typical mineral, coal or oil sands processing operation, waste solids are separated from solids that contain mineral valuables or hydrocarbon in an aqueous process.
The aqueous suspensions of waste solids often contain clays and other minerals and are usually referred .. to as tailings. These solids are often concentrated by a flocculation process in a gravity thickener to give a higher density underflow and to recover some of the process water.
In some cases, the waste material such as mine tailings can be conveniently disposed of in an underground mine as backfill. Generally, this waste comprises a high proportion of coarse large sized particles together with other smaller sized particles and is pumped into the mine .. as a slurry, occasionally with the addition of a pozzolan, where it is allowed to dewater leaving a sedimented solid in place. It is commonplace to use flocculent to assist this process by flocculating the fine material to increase the rate of sedimentation. However, in

2 Date Recue/Date Received 2022-03-14 BASF SE

this instance, the coarse material will normally sediment at a faster rate than the flocculated fines, resulting in a heterogeneous deposit of coarse and fine solids.
For other applications it may not be possible to dispose of the waste in an underground mine. In these cases, it is common practice to dispose of the material, by pumping the aqueous slurry or underflow to lagoons, heaps or stacks, which may be above ground, or into open mine voids, or even purpose-built dams or containment areas. It is usual to pump the aqueous slurry to a surface holding area, often referred to as a tailings pit or dam or more usually a tailings pond in the case of oil sands. This initial placement of the mining waste into the disposal area may be as a free-flowing liquid, thickened paste or the material may be further treated to remove much of the water, allowing it to be stacked and handled as a solid-like material. Once deposited at this surface holding area, water will continue to be released from the aqueous suspension resulting in further concentration of the solids over a period of time through the actions of sedimentation, drainage and evaporation.
Once a sufficient volume of water has been collected this is usually pumped back to the mineral or oil sands processing plant.
For example, in the case where the tailings are sent to the disposal area in a liquid and fluid form, they must be contained in a lagoon by dams or similar impoundment structures. The tailings may have been pretreated by adding flocculating agents and thickened in a gravity thickener to remove and recover some of the water content, but the overall solids content is such that the fluid has no, or a low yield stress, and hence the material behaves largely as a liquid on deposition. These lagoons may be relatively shallow, or relatively deep, depending upon how much land is available, the location for building impoundment area and other geotechnical factors generally within the vicinity of the mine site. Dependent upon the nature of the solid particles in the waste, often the particles will gradually settle from the aqueous slurry and form a compact bed at the bottom of the deposition area. Released water may be recovered by pumping or is lost to the atmosphere through evaporation and groundwater through drainage. It is desirable to remove the aqueous phase from the tailings whereby the geotechnical moisture content is below the liquid limit of tailings solids, in order to manage the remaining tailings in a form that has a predominantly solid or semi-solid handling characteristic. Numerous methods can be employed to achieve this, the most common, when the material properties of the tailings allow, is self-weight consolidation in a tailings dam, whereby the permeability of tailings is enough to overcome the filling rate of the dam and water can be freely released from the tailings. Where the permeability of the tailings is not sufficient for water to escape freely, polymers are typically used to improve permeability thereby making the tailings more suitable for a self-weight consolidation process. Eventually,

3 Date Recue/Date Received 2022-03-14 BASF SE

it may be possible to rehabilitate the land containing the dewatered solids when they are sufficiently dry and compact. However, in other cases, the nature of the waste solids will be such that the particles are too fine to settle completely into a compact bed, and although the slurry will thicken and become more concentrated overtime, it will reach a stable equilibrium .. whereby the material is viscous but still fluid, making the land very difficult to rehabilitate. It is known that the flocculants are sometimes used to treat the tailings before depositing them into the disposal area, to increase the sedimentation rate and increase the release of water for recovery or evaporation.
In an alternative method, the tailings may be additionally thickened, often by the treatment with polymeric agents, such that the yield stress of the material increases so that the slurry forms heaps or stacks when it is pumped into the deposition area. Specialised thickening devices such as Paste Thickeners or Deep Cone Thickeners may be used to produce an underflow with the required properties. Alternatively, the polymeric agents may be added the tailings slurry during the transfer or discharge into the disposal area, to render the material less mobile and achieve the required yield stress. This heaped geometry aids more rapid dewatering and drying of the material to a solid-like consistency as the water is removed and recovered more rapidly through run-off and drainage, and the compaction of the solids may occur more rapidly through the increased weight and pressure of the solids when formed into a heap or a stack. In some instances, the deposition of the solids is controlled to build up relatively narrow bands of tailings which can also dewater quickly through evaporation, prior to adding a new layer of treated waste material on top. This is sometimes referred to as thin lift or dry stacking. Typically, each relatively narrow band of tailings (i.e.
each layer of treated waste material) would tend to have a thickness of from 0.1 to 0.5 m. In the case of red mud, this material often has sufficient yield stress to form the layered stacks without further polymer treatment and this method has been widely used to dispose of tailings from alumina processing for a number of years. Air drying of tailings can be used to great effect where the environment has some evaporation potential and there is enough land area to spread the tailings thinly enough for this process to be effective. Where the area for evaporation is .. limited it is possible for the polymers to be added to the tailings to improve this process. The addition of the polymer may increase the permeability of the tailings whereby at least about 20% by weight of water can be allowed to drain, while another 20% of the water that is typically more associated with the particle surfaces and the clay matrix can be removed through evaporation.
It is often useful for the tailings pond or dam to be of limited size to minimise the impact on the environment. In addition, providing larger tailings ponds can be expensive due to the

4 Date Recue/Date Received 2022-03-14 BASF SE

high costs of earthmoving and the building of containment walls. These ponds tend to have a gently sloping bottom which allows any water released from the solids to collect in one area and which can be pumped back to the plant. A problem that frequently occurs is when the size of the tailings pond and the dam are not large enough to cope with the output of tailings from the mineral processing operation. Another problem that frequently occurs is when fine particles of solids are carried away with the run-off water. Thus, the released water containing the fine particles could have a detrimental impact on recycling and subsequent uses of the water.
Another method for disposal of the mine tailings is to use mechanical dewatering devices such as filters and centrifuges. Such mechanical dewatering devices are able to remove a significant amount of water from the aqueous minerals slurry, such that the waste material may be deposited in the disposal area directly with a solid like consistency.
In many cases, it is necessary to treat the tailings with polymeric flocculating agent immediately prior to the mechanical dewatering step, to enable this equipment to perform efficiently and achieve the degree of dewatering required.
A further method for disposal of the mine waste is through filtration in a Geotube , whereby the aqueous slurry placed into a permeable geotextile bag which retains the solids particles and some of the water is released by a filtration process, escaping through the walls of the geotextile bag. In some cases, where the starting permeability of the mine tailings is low, it may be desirable to add a flocculating agent in order to increase the filtration rate and improve the retention of fine solids within the Geotube .
For example, in oil sands mining, the ore is processed to recover the hydrocarbon fraction, and the remaining material, constitutes the tailings. In the oil sands extraction process, the main process material is water, and the tailings are mostly sand with some silt and clay, with some residual bitumen. Physically, the tailings consist of an easily dewatered, solid part (sand tailings) and a more fluid part (sludge). The most satisfactory place to dispose of the .. tailings, is of course in the existing excavated hole in the ground.
Nevertheless, the sand tailings alone from the one cubic foot of ore occupy just about one cubic foot. The amount of sludge is variable, depending on the ore quality and process conditions, but average about 0.3 ft3. The tailings simply will not fit into the hole in the ground.
Therefore, there is generally a requirement to build additional impoundment areas for the tailings.
Within the oil sands industry, there are many different types of process tailings streams as defined in Technical Guide for Fluid Fine Tailings Management, COSIA 2012, which may

5 Date Recue/Date Received 2022-03-14 BASF SE

require treatment with polymeric agents. One example is "fine fluid tailings"
(FFT) which is the fines fraction (mainly silt and clay) from the process after the hydrocarbon content has been largely recovered, and the sand fraction has been largely removed, usually by passing the "whole tailings" (WT) through a cyclone. The solids content of the fine fluid tailings may vary significantly, depending upon if material has been thickened by gravity sedimentation.
Whole Tailings (WT) may be regarded as tailings produced from primary or secondary separation vessels of the extraction plant and contains sand, fines and water.
In general, the sand to fines ratio of the WT are greater than 4:1 and may be as high as 20:1.
Another example is "composite tails" (CT) in which all the particle size ranges are present (sand, silt and clay). This may be the whole tailings, prior to the removal of the sand, or other tailings streams which may be formed by subsequent mixing of fine tailings with sand fractions, to varying degrees. The sand to fines ratio of CT tends to be greater than 3:1 and may be as high as 6:1 or 7:1. A further example is "mature fines tailings"
(MFT) which are formed after storage of fluid fine tailings, or in some cases combine tailings, in a tailings pond for several years. FFT tends to have sand to fines ratios significantly below 1:1 and MFT tend have much lower sand contents typically less than 0.3:1, for instance less than 0.25:1.
In the oil sands fine tailings pond, the process water, any residual hydrocarbons and minerals settle naturally to form different strata. The upper stratum can be predominantly water that may be recycled as process water to the extraction process. The lower strata can contain settled residual hydrocarbon and minerals which are predominantly fines, usually clay. It is usual to refer to this lower stratum as mature fines tailings. It is known that mature fines tailings consolidate extremely slowly and may take many hundreds of years to settle into a consolidated solid mass. Consequently, mature fines tailings and the ponds containing them are a major challenge to tailings management and the mining industry.
The composition of mature fines tailings tends to be variable. The upper part of the stratum may have a mineral content of about 10% by weight but at the bottom of the stratum the mineral content may be as high as 50% by weight. The variation in the solids content is believed to be because of the slow settling of the solids and consolidation occurring over time. The average mineral content of the MFT tends to be of about 30% by weight. MFT
behaviour is typically dominated by clay behaviour, with the solids portion of the MFT
behaving more as a plastic-type material than that of a coarser, more friable sand.
The MFT frequently comprises a mixture of sand, fines and clay. Generally, the sand is defined as siliceous particles of any size greater than 44 pm and may be a component of the

6 Date Recue/Date Received 2022-03-14 BASF SE

MFT solids in an amount of up to 50% by weight. The remainder of the mineral content of the MFT tends to be made up of a mixture of clay and fines (silts). Generally, fines refer to mineral particles no greater than 44 pm. The clay may be any material traditionally referred to as clays by virtue of its mineralogy and will generally have a particle size of below 2 pm.
Typically, the clays tend to be a blend of kaolin, illite, chlorite and water swelling clays, such as smectites which are sometimes referred to as montmorillonites and may be interlayered with the other types of clay. Additional variations in the composition of MFT
may be as a result of the residual hydrocarbon which may be dispersed in the mineral tailings and may segregate in the tailings pond into mat layers of hydrocarbon. The MFT in a pond not only has a wide variation of compositions distributed from top to bottom of the pond but there may also be pockets of different compositions at random locations throughout the pond.
It has been known to treat aqueous slurry such as tailings using polymer flocculants. See, for example, any of:
EP-A-388108;
WO 96/05146;

7;
WO 04/060819;
WO 01/05712; and WO 97/06111.
Canadian patent 2,803,904 teaches the use of high molecular weight multi valent anionic polymers for clay aggregation. Specifically, a polymer comprising an anionic water-soluble multivalent cation-containing acrylate copolymer is described.
Canadian patent 2,803,025 teaches a polymer similar to the polymer taught in Canadian patent 2,803,904 with the proviso that the polymer has an intrinsic viscosity of less than 5 dl/gm.
WO 2017/084986 describes a multivalent cation containing copolymer derived from one or more ethylenically unsaturated acids. The copolymer has the following characteristics: (a) an intrinsic viscosity of at least about 3 dl/g when measured in 1 M NaCI
solution at 25 C; (b) the copolymer is derived from a monomer mixture comprising an ethylenically unsaturated acid and at least one comonomer, the ethylenically unsaturated acid present in an amount in the range of from about 5% to about 65% by weight; and (c) a residual comonomer content of less than 1000 ppm when the comonomer is an acrylamide. The copolymer, inter-alia, is Date Recue/Date Received 2022-03-14 BASF SE

useful as a flocculent for treating an aqueous slurry comprising particulate material, preferably tailings from a mining operation.
US 2018/0201528 describes a method of dewatering an aqueous mineral suspension comprising introducing into the suspension flocculating system comprising a mixture of polyethylene glycol and polyethylene oxide polymers. The mixture of polyethylene glycol and polyethylene oxide polymers is said to be useful for the treatment of suspensions of particulate material, especially waste mineral slurries and is said to be particularly suitable for the treatment of tailings and other waste material resulting from mineral processing, in particular, the processing of oil sands tailings.
US 2016/0362316 describes a method for monitoring and controlling flocculation of oil sands fine tailings in a pipeline. The method comprises injecting a polymeric flocculent into a tailings feed being pumped through the pipeline and involves mixing the polymeric flocculent and tailings feed in the pipeline, and providing one or more adjustable valves in the pipeline that are operable to either reduce the flow area of the adjustable valve to increase shear or dispersed energy when the polymeric flocculent and tailings feed are under mixed or increase the flow area of the adjustable valve to decrease shear or dispersed energy when the polymeric flocculent and tailings feed are overmixed.
Chongchong et al., "Cemented paste backfill for mineral tailings management:
Review and future perspectives", Minerals Engineering, Elsevier, Amsterdam, NL, vol. 144, September 2019 refers to environmental issues associated with tailings management in the mining industry. The article refers disposal of mineral tailings in a technical, environmental and economical way. Cemented paste backfill (CPB) technology is referred to in the article which sets out to summarise recent progress on CPB design, with particular emphasis on flocculation and sedimentation, CPB mixed design and CPB pipe transport.
Updates in underlying mechanisms, experimental techniques, influencing factors and recent frontiers are identified in this article.
Clay-based minerals are known to cause problems in mineral processing operations. When the mined ore contains significant amounts of clay, then treatment and disposal of the waste (gangue) material after the recovery (beneficiation) of the valuables is often problematic.
This is because the stacked platelets of a clay mineral particle tend to delaminate (or break apart) when contacted with water and these delaminated platelets form (or rearrange into) network type structures held together by electrostatic forces between the edges and the faces of the clay platelets. The high specific surface area, combined with the hydrophilic

8 Date Recue/Date Received 2022-03-14 BASF SE

nature of the surfaces, causes water to become trapped with solids, and the waste is then difficult to concentrate and dewater. This can result in both excessive volumes of waste material, soft deposits which do not compact readily over time, and loss of process water.
Polymeric flocculants, such as Magnafloc and Rheomax ETD ranges, supplied by BASF, have been used to enhance the rate of settling and dewatering of tailings deposits. However, in some cases, whilst the polymers do improve the rate and extent of water removal to some degree, this is not sufficient to increase the solids content of the material beyond the plastic limit of the system and, further self-weight compaction does not occur, leading to the creation of soft deposits which are not suitable for rehabilitation.
One such example is the Canadian oil sands industry, where it is well documented that their fine tailings will remain semi-fluid for many hundreds of years, except where the process allows for a significant amount of water evaporation and atmospheric drying.
This problem is especially the case for deep pour deposits of tailings, which make the most effective use of land and mining voids but have limited opportunity for evaporative dewatering.
Evaporation to dewater tailings to a solids content above the plastic point can only be used on relatively thin layers of deposited tailings, which requires a massive area of land to operate effectively.
Another industry which also produces problematic high clay containing tailings is the phosphate industry, for example in Florida, USA.
WO 2020/089271 reveals a process for separating solids from an aqueous slurry containing clay containing particulate material having sand particles and fines particles. The aqueous slurry has a solids content of from 25 to 70% by weight and a sand to fines ratio of from 0.5:1 to 5:1. The process comprises applying a treatment system to the aqueous slurry which causes flocculation of the particulate material with subsequently separating the so formed flocculated particulate solids from the slurry. This treatment system comprises (a) at least one ionic polymeric decoagulant which has a weight average molar mass of below 2 million g/mol; and at least one polymeric flocculent, which has an intrinsic viscosity of at least 5 dl/g (measured at 25 C in 1 M NaCI); and (c) optionally, at least one cationic coagulant.
The disclosure provides an effective process for dewatering waste solids that contain clays.
Canadian application CA 3077551 Al describes a process for separating solids from an aqueous slurry containing particulate material. The particulate material comprises sand particles and fines particles and contains clay particles. Said aqueous slurry has a solids content of from 30 to 70% by weight and a sand to fines ratio greater than 1:1 to 3:1. The process involves the addition of (a) at least one aluminosilicate nano particulate material, in

9 Date Recue/Date Received 2022-03-14 BASF SE

which the molar ratio of aluminium to silicon is from 0.7:1 to 3:1; (b) at least one polymeric flocculent, which has an intrinsic viscosity of at least 5 dl/g (measured at 25 C in 1 M NaCI);
and (c) optionally, at least one cationic coagulant. This process is an effective process for dewatering waste solids that contain clays.
It would be desirable to provide a process for separating solids from tailings slurries to enable effective operation of the separating process. It is also a potential objective to provide an improved method for treating slurries so as to provide efficient recovery of aqueous liquor and separation of the solids. This is particularly so where it is desirable to efficiently provide the solids content from a tailings slurry in a form that can be suitable for disposal and facilitate the efficient recovery of as much of the aqueous liquor as feasible.
Summary of the Invention The present invention provides a method for separating solids from a tailings slurry (TS), which tailings slurry (TS) has a solids content of from 25 to 70% by weight and comprises sand particles and fines particles with a sand to fines ratio (SFR) of from 0.5:1 to 5:1, wherein the fines particles comprise clay, a. forming at least one first mass flow (MS1) of the tailings slurry (TS) entering at least one containment, which the at least one containment comprises at least one first mixing region (MR1), b. subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG1) in the at least one first mixing region (MR1), wherein fluidity measurements (FM1) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MR1) to exiting the at least one first mixing region (MR1), c. optionally flowing the tailings slurry (TS) from the at least one first mixing region (MR1) to at least one second mixing region (MR2) as at least one second mass flow (M52), said at least one second mixing region (MR2) having at least one agitation means (AG2), d. optionally subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG2) in the at least one second mixing region (MR2), wherein fluidity measurements (FM2) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), e. adding a clay de-coagulant reagent (DGR) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one first mass flow (MS1) and the at Date Recue/Date Received 2022-03-14 BASF SE

least one first mixing region (MRI), said at least one first mixing region (MRI) having at least one agitation means (AGI), f. adding a flocculent (F) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one at least one first mass flow (MS1), the first mixing region (MRI), the at least one second mass flow (M52) and the at least one second mixing region (MR2), g. flowing the tailings slurry (TS) from either or both (i) the at least one first mixing region (MRI) and/or (ii) the at least one second mixing region (MR2) as at least one conditioned tailings stream (CTR), h. separating the at least one conditioned tailings stream (CTR) into a solids rich phase and a solids depleted liquor, wherein the method comprises (A) at least one item of information (11);
(B) optionally at least one item of information (13);
(C) optionally at least one item of information (14); and (D) at least one item of information (15), wherein A. the at least one item of information (11) is associated with the at least one first mass flow (MSI) and is directly or indirectly selected from the group consisting of the sand to fines ratio (SFR); the solids content; the specific gravity; the clay content and the flow rate, B. the at least one item of information (13) is associated with the fluidity measurements (FM1) showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MRI) to exiting the at least one first mixing region (MRI), C. the at least one item of information (14) is associated with fluidity measurements (FM2) showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), D. the at least one item of information (15) is associated with (15a) the at least one conditioned tailings stream (CTR); and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated therefrom, wherein (15a) is associated with changes to the structure of the conditioned tailings stream (CTR) and (I5b) is associated with changes in at least one of the group selected from solids/liquid separation rate;
volume of released liquid; turbidity of released liquid; and moisture content of separated solids, Characterised in that, Date Recue/Date Received 2022-03-14 BASF SE

either (I) the method comprises the at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) to mixing in the at least one first mixing region (MR1) and the at least one second mixing region (MR2) and includes subjecting the tailings slurry (TS) to mixing in the at least one second mixing region (MR2), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii), (iii) and (iv):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), (iv) the initial rate of mixing provided by the at least one agitation means (AG2), and (v) reset at least one of (i) to (iv) according to said predefined conditions, in which at least one of (IA) and/or (1B) are employed, (IA) the at least one item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AGI), and/or (1B) the combination of at least one item of information (14) and at least one item of information (15) is used to adjust the rate of mixing provided by the at least one agitation means (AG2);
and the at least one item of information (15) is used to adjust the dose of either the clay de-coagulant reagent (DGR) and/or the flocculent (F), or (II) the method employs as mixing region(s) solely at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) to mixing in the at least one first mixing region (MRI), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii), and (iii):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), Date Recue/Date Received 2022-03-14 BASF SE

and (v) reset at least one of (i) to (iii) according to said predefined conditions;
and the combination of at least one item of information (15) and at least one item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AG1);
and the at least one item of information (15) is used to adjust the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F).
By operating the method of the invention effective control of the separation process can be achieved. In particular, the method facilitates efficient use of the clay decoagulant reagent (DGR) and flocculent (F) and the ability to achieve efficient treatment of the tailings slurry (TS) and optimal separation of the solids.
Description of Drawings Figure 1 shows a flowchart diagram of one potential embodiment for the carrying out inventive method of separating solids from the tailings slurry (TS) in which the first mixing region (MR1) and the second mixing region (MR2) are each located in separate vessels.
Figure 2A shows a flowchart diagram of another potential embodiment for carrying out the inventive method in which the first mixing region (MR1) and the second mixing region (MR2) are each located in the same vessel, each region separated by an orifice plate.
Figure 2B shows a flowchart diagram of another potential embodiment for carrying out the inventive method in which the first mixing region (MR1) and the second mixing region (MR2) are each located in the same vessel, each region separated by a constriction.
Figure 3 provides a graphical representation of the natural coagulation state of clays, showing a plot of suspension (aqueous slurry) viscosity (mPas) versus pH and providing two-dimensional representations of the respective coagulated structure of the clay platelets.

Date Recue/Date Received 2022-03-14 BASF SE

Figure 4 illustrates a pressure filter apparatus consisting of a cylindrical chamber of diameter 3.25 cm, fitted with fine filter media at one end, and a solid sliding piston at the other.
Figure 5 represents an apparatus for the treatment of Tailings Slurry (TS) comprising a single mixing region (MRI) comprising a dynamic in-line mixer. The Dynamic In-Line Mixer containing the first mixing region (MRI) is a flow through mechanically agitated tank reactor.
The fluidity measurements (FM1/I to FM1/4), such as internal process pressure, is measured (OPMI) at four positions on the side wall and transmitted to the PLC
(13).
Figure 6 is a representation of an apparatus for the treatment of Tailings Slurry (TS) comprising 2 mixing regions (MRI) and (MR2). The Static In-line Mixer (MRI) is a helical element inserted into a 12.5mm ID pipe, with a total length of approximate 300mm. The change in fluidity measurements (FM1), for instance pressure drop across the in-line mixer is measured (OPMI) and transmitted to the PLC (13). The Dynamic In-Line Mixer (MR2) is the same as described in Figure 5.
Detailed Description of the Invention Desirably first mixing region (MRI) typically means a mixing region in which the first mass flow (MSI) undergoes significant agitation by the at least one agitation means (AGI) and second mixing region (MR2) typically means a subsequent mixing region to the first mixing region (MRI) and in which the tailings slurry (TS) undergoes significant agitation in the second mixing region (MR2) by the at least one agitation means (AG2) and leaves the mixing region as a conditioned tailings stream (CTR).
The tailings slurry (TS) in the optional at least one second mass flow (M52) may flow directly or indirectly into the at least one second mixing region (MR2). By indirectly we mean that the flow of the tailings slurry (TS) may be interrupted by one or more stages, for instance in a holding region, such as a tank or vessel, or an additional mixing stage, before being delivered into the at least one second mixing region (MR2). Preferably the tailings slurry (TS) in the second mass flow (M52) flows directly from the at least one first mixing region (MRI) into the at least one second mixing region (MR2).
In the first aspect of the present invention comprising at least one first mixing region (MRI) and at least one second mixing region (MR2) the at least one item of information (11) associated with the at least one first mass flow (MSI) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii), (iii) and (iv):

Date Recue/Date Received 2022-03-14 BASF SE

(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), (iv) the initial rate of mixing provided by the at least one agitation means (AG2), and (v) reset at least one of (i) to (iv) according to said predefined conditions.
In the second aspect of the present invention the method employs as mixing region(s) solely at least one first mixing region (MRI), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii) and (iii):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), and (v) reset at least one of (i) to (iii) according to said predefined conditions, The at least one item of information (11) may provide a measure of the composition and/or a property of the tailings slurry (TS) in the at least one first mass flow (MS1). This could be information collected on one or more parameters associated with the tailings slurry (TS) and provide directly or indirectly data which reveals certain physical parameters or characteristics of the tailings slurry (TS) in the at least one first mass flow (MS1), such as solids content, the specific gravity, sand to fines ratio (SFR), the clay content, and the flow rate of the first mass flow (MS1) or some other parameter associated with the state of de-coagulation of the clay component or any combination of these.
In the first aspect of the present invention the method employs at least one first mixing region (MRI) and at least one second mixing region (MR2), the at least one item of information (13) to adjust the rate of mixing provided by the at least one agitation means (AGI). The at least one item of information (13) is associated with the fluidity measurements (FM1) which show any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MRI) to exiting the at least one first mixing region (MRI). Typically, this may be information relating to the mixing and/or flow characteristics of the tailings slurry (TS) in the first mixing region (MRI). The fluidity measurements (FM1) may be obtained through at least one sensor which measures at least one item selected from the group consisting of vibration, acoustics and pressure. In one desirable form the fluidity measurements (FM1) relate to pressure and may be termed output pressure measurements Date Recue/Date Received 2022-03-14 BASF SE

(OPM1). The fluidity measurements (FM1), desirably being output pressure measurements (OPM1), would tend to relate to the flow characteristics of the tailings slurry (TS) typically in the vicinity of the periphery of the at least one first mixing region (MR1), for instance in close proximity to the wall of the containment, for instance vessel, in which the first mixing region (MR1) is contained.
In this first aspect of the present invention, the method employs at least one first mixing region (MR1) and at least one second mixing region (MR2), the at least one item of information (14) would be used in combination with at least one item of information (15) to adjust the rate of mixing provided by the at least one agitation means (AG2).
The at least one item of information (14) is associated with the fluidity measurements (FM2) which show any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2).
Typically, this may be information relating to the mixing and/or flow characteristics of the tailings slurry (TS) in the at least one second mixing region (MR2). The fluidity measurements (FM2) may be obtained through at least one sensor which measures at least one item selected from the group consisting of vibration, acoustics and pressure. In one desirable form the fluidity measurements (FM2) relate to pressure and may be termed output pressure measurements (OPM2). The fluidity measurements (FM2), desirably being output pressure measurements (OPM2), would tend to relate to the flow characteristics of the tailings slurry (TS) typically in the vicinity of the periphery of the at least one second mixing region (MR2), for instance in close proximity to the wall of the containment, for instance vessel, in which the at least one second mixing region (MR2) is contained.
In accordance with this first aspect of the invention at least one of (IA) the at least one item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AG1), and/or (1B) the combination of item of information (14) and at least one item of information (15) is used to adjust the rate of mixing provided by the at least one agitation means (AG2), should be employed.
Preferably where only one of (IA) and (1B) are employed in the inventive method, it is feature (1B) that should be employed. More preferably both features (IA) and (1B) should be used in the inventive method.
The second aspect of the method according to the present invention employs as mixing region(s) solely at least one first mixing region. By this we mean the method employs at least Date Recue/Date Received 2022-03-14 BASF SE

one first mixing region (MR1) but not a second mixing region (MR2). The at least one item of information (13) would be used in combination with at least one item of information (15) to adjust the rate of mixing provided by the at least one agitation means (AG1).
The at least one item of information (13) is associated with the fluidity measurements (FM1) which show any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MR1) to exiting the at least one first mixing region (MR1). Typically, this may be information relating to the mixing and/or flow characteristics of the tailings slurry (TS) in the first mixing region (MR1). The fluidity measurements (FM1) may be obtained through at least one sensor which measures at least one item selected from the group consisting of vibration, .. acoustics and pressure. In one desirable form the fluidity measurements (FM1) relate to pressure and may be termed output pressure measurements (OPM1). The fluidity measurements (FM1), desirably being output pressure measurements (OPM1), would tend to relate to the flow characteristics of the tailings slurry (TS) typically in the vicinity of the periphery of the at least one first mixing region (MR1), for instance in close proximity to the .. wall of the containment, for instance vessel, in which the first mixing region (MR1) is contained.
The at least one item of information (15) is associated with (15a) the at least one conditioned tailings stream (CTR); and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated therefrom. The at least one item of information (15a) is associated with changes to the structure of the conditioned tailings stream (CTR).
Typically, this may relate to structure of the solids within the conditioned tailings stream (CTR). This may relate to the degree of flocculation of the conditioned tailings stream (CTR) and in particular the structure of flocculated solids. How well flocculated the solids are in the conditioned tailings .. stream (CTR) may indicate how efficiently the solids will separate from the liquid of the conditioned tailings stream (CTR). Suitably changes in the structure of the at least one conditioned tailings stream (CTR) may be obtained through at least one instrument which gathers information selected from at least one item of the group consisting of tomography, imaging, vibration and acoustics. Desirably the at least one item of information (15a) associated with changes to the structure of the at least one conditioned tailings stream (CTR) detects if the at least one conditioned tailings stream (CTR) is exhibiting turbulent flow or substantially nonturbulent flow, wherein suitably nonturbulent flow is laminar flow. A
particularly suitable instrument for gathering the at least one item of information (15a) is an accelerometer. Another suitable instrument for gathering at least one item of information (15a) may for instance be a vibrometer.

Date Recue/Date Received 2022-03-14 BASF SE

The at least one item of information (I5b) is associated with components of the at least one conditioned tailings stream (CTR) separated therefrom. This may be, for instance the ability of the at least one conditioned tailings stream (CTR) to undergo dewatering, for instance by sedimentation or pressure dewatering, such as pressure filtration. The item of information may instead or in addition relate to the components of the at least one conditioned tailings stream (CTR) separated therefrom. This may, for instance, be the moisture content of the separated solids, the rheological properties of the separated solids, for instance yield stress, the compressibility characteristics of the solids or the turbidity of the liquid separated from the at least one conditioned tailings stream (CTR). Desirably the at least one item of information (I5b) associated with components of the at least one conditioned tailings stream (CTR) is provided by an instrument adapted to take measurements associated with the separation and wherein the measurements are selected from the group consisting of separation rate, turbidity of the liquor separated from the at least one conditioned tailings stream (CTR), solids content of the solid material separated from the at least one .. conditioned tailings stream (CTR) and moisture content of the solid material separated from the at least one conditioned tailings stream (CTR).
In one desirable embodiment the method of the present invention additionally employs at least one item of information (12) which is associated with at least one second mass flow (M52) and is associated with changes to the structure of the at least one second mass flow (M52). The at least one item of information (12) may give information associated with changes to the structure of the tailings slurry (TS) in the at least one second mass flow (M52). Typically, this may relate to structure of the solids within the at least one second mass flow (M52). This may relate to the degree of flocculation of the tailings slurry (TS) in the at least one second mass flow (M52) and in particular the structure of flocculated solids.
How well flocculated the solids are in the tailings stream (TS) in the at least one second mass flow (M52) may indicate how efficient the degree of mixing is in the at least one first mixing region (MR1) is and how effective the de-coagulation of the clay with the decoagulant reagent (DGR) and/or the degree of flocculation of the solids with the flocculent (F) are.
Suitably changes in the structure of the at least one second mass flow (M52) may be obtained through at least one instrument which gathers information selected from at least one item of the group consisting of tomography, imaging, vibration and acoustics. Desirably the at least one item of information (12) associated with changes to the structure of the at least one second mass flow (M52) detects if the at least one second mass flow (M52) is exhibiting turbulent flow or substantially non-turbulent flow, wherein suitably non-turbulent flow is laminar flow. A particularly suitable instrument for gathering the at least one item of Date Recue/Date Received 2022-03-14 BASF SE

information (12) is an accelerometer. Another suitable instrument for gathering at least one item of information (12) may for instance be a vibrometer.
In this desirable embodiment at least one item of information (12) may be used in combination with item of information (13) to adjust the rate of mixing provided by the at least one agitation means (AG 1); and said item of information (12) may be used in combination with item of information (15) to adjust the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F).
In the method according to the present invention, it may be desirable additionally to control at least one of the following parameters:
= the point of addition of the clay decoagulant reagent (DGR) added to the tailings slurry (TS);
= the point of addition of the flocculent (F) added to the tailings slurry (TS);
= the sand to fines ratio (SFR) of the at least one first mass flow (MS1);
= the solids content of the at least one first mass flow (MS1); or = the flow rate of the at least one first mass flow (MS1).
In one desirable form the method may control the point of addition of the clay decoagulant reagent (DGR) added to the tailings slurry (TS) and specifically control of whether the clay decoagulant reagent (DGR) is dosed into the at least one first mass flow (MS1) and/or the at least one first mixing region (MR1). In another such desirable form the method may control the point of addition of the flocculent (F) added to the tailings slurry (TS) and specifically control whether the flocculent (F) is dosed into the at least one first mass flow (MS1) and/or the at least one first mixing region (MR1) and/or the at least one second mass flow (M52) and/or the at least one second mixing region (MR2). In one further desired form, the method may control both the point of addition of the clay decoagulant reagent (DGR) added to the tailings slurry (TS) and the point of addition of the flocculent (F) added to the tailings slurry (TS). The initial setpoint for the points of addition for each of the clay decoagulant reagent (DGR) and/or the flocculent (F) may be determined from the at least one item of information (II) according to predefined conditions, which may also be used for resetting the respective points of addition. Variations in the respective points of addition for the clay decoagulant reagent (DGR) and/or the flocculent (F) may be in response to the at least one item of information (15).

Date Recue/Date Received 2022-03-14 BASF SE

The tailings slurry (TS) may desirably be formed by combining a multiplicity of component tailings streams. This may also be in addition to combining a water stream.
Thus, the method may involve combining a first tailings stream (FTS) and a second tailings stream (STS) to form the tailings slurry (TS). In this case the first tailings stream (FTS) would have a lower sand to fines ratio (SFR) than the second tailings stream (STS).
Preferably, the first tailings stream (FTS) would have a sand to fines ratio (SFR) of less than 1:1, preferably less than 0.5:1, and the second tailings stream would have a sand to fines ratio (SFR) greater than 3:1, preferably greater than 5:1. Thus, in this form the tailings slurry (TS) may be formed from a sand depleted tailings slurry, i.e. representing the first tailings stream (FTS) and a sand rich tailings slurry, i.e. representing the second tailings stream (STS).
The method is particularly suitable for treating sand depleted tailings slurries which are notoriously difficult to bring about efficient solids liquid separation. It is believed that this may be as a result of high concentrations of clay in the slurry and in which the clay is in a .. particularly coagulated form. One such sand depleted tailings slurry includes mature fines tailings (MFT) which often have sand to fines ratios (SFR) significantly below 1:1 and often in the region of below 0.5:1 or lower. Preferably, the first tailings stream (FTS) is a mature fines tailings (MFT). Suitable examples of the second tailings stream (STS) include whole tailings (WT) or the underflow from a cycloned whole tailings (WT).
Thus, in accordance with the present method the sand to fines ratio (SFR) of the tailings slurry (TS) may be controlled by varying the ratio of component tailings streams with different sand to fines ratios (SFR). This corresponds to the control of the sand to fines ratio (SFR) of the tailings slurry (TS) in the at least one first mass flow (MSI).
The sand to fines ratio (SFR) in the first mass flow (MSI) may be adjusted to be maintained within the required optimal range in response to the measured SFR in the first mass flow (MSI) as an item of information (11). Thus, as the SFR is measured to fall below the required threshold of optimal SFR the sand rich tailings stream component of the tailings slurry (TS) can be increased or the sand depleted tailings stream component of the tailings slurry (TS) can be decreased to bring the tailings slurry (TS) within the optimal SFR
range. Likewise, as the measured SFR increases beyond the required threshold of optimal SFR the sand rich tailings stream component of the tailings slurry (TS) can be decreased or the sand depleted tailings stream component of the tailings stream (TS) can be increased to bring the tailings slurry (TS) within the optimal SFR range.
Date Recue/Date Received 2022-03-14 BASF SE

The tailings slurry (TS) should have a solids content of from 25 % to 70% by weight of the aqueous slurry. Preferably, the tailings slurry may have a solids content of from 30% to 70%
by weight of the aqueous slurry. The tailings slurry (TS) to be treated may already have a solids content within this range. Typically, however, an aqueous slurry may have undergone some sort of initial thickening stage where an amount of the aqueous liquid may have been removed. Such an initial thickening stage may, for instance, be a sedimentation stage, such as in a thickening or sedimentation vessel or in a pit. Alternatively, the thickening stage may include a belt thickener or a centrifuge. Other means of bringing the solids content to within the required range may also be possible. Where the solids content of the tailings slurry (TS) needs to be reduced this can be achieved by the addition of a water stream, i.e. dilution water which may be recycled process water, or by adding a component tailings stream of much lower solids. Thus, in accordance with the present invention the solids content of the tailings slurry (TS) in the first mass flow may be controlled by varying the component tailings streams and/or water stream to achieve the desired solids content. This corresponds to controlling of the solids content of the tailings slurry in the at least one first mass flow (MSI).
Suitably this may be achieved in response to at least one item of information (11). Thus, when the at least one item of information (11) contains information about the solids content of the tailings slurry (TS), where the information indicates that the solids content falls outside acceptable limits according to predefined conditions for that tailings stream (TS) the solids content may be adjusted to bring the solids content to within the required range, for instance as described above, for instance for the solids content to be adjusted to be within the optimal solids content range. Hence, when the at least one item of information (11) indicates that the solids content of the tailings slurry (TS) falls below the required range the solids content can be increased as herein indicated. When on the other hand the at least one item of information (11) indicates that the solids content of the tailings slurry (TS) is higher than the required range the solids content can be decreased as herein indicated.
The inventors have found that the employment of the inventive method can facilitate the co-disposal of the fines and the sand. Desirably, this method enables the deposited solids separated from the aqueous slurry to contain both the fines and sand particles forming a relatively homogenous deposit with minimal segregation of fines and sand particles.
Prevention of segregation during co-disposal of the fines and sand particles is important because otherwise the heavier sand particles would tend to settle faster while the fines would take longer to settle and would tend to be washed away with the liquid separated from the slurry. Thus, in the process according to the invention the liquid separated from the aqueous slurry tends to have a lower fines particles content. This can be measured by well-known filtration techniques. Suitably, the liquid separated from the aqueous slurry should Date Recue/Date Received 2022-03-14 BASF SE

have a solids content of less than 5% by weight of the total separated liquid.
Preferably the solids content is less than 2% by weight of the total separated liquid, more preferably less than 1% by weight of the total separated liquid, even more preferably from 0.001% to 0.75%
by total weight of the separated liquid, still more preferably from 0.01% to 0.5% by total weight of the separated liquid, often from 0.01% to 0.1% by total weight of separated liquid.
The particulate material contained in the aqueous slurry includes sand and fines. By sand we mean mineral solids (excluding gravel) with a particle size greater than 44 pm and generally less than 2 mm (not including bitumen). By fines we mean mineral solids, such as silts, with a particle size of equal to or less than 44 pm (not including bitumen). In general, the clay component of the aqueous slurry is part of the fines component. Thus, fines include the clay component as well as any other non-clayey mineral particles of the aforementioned size range. The particulate solid material contained in the aqueous slurry usually comprises a sand to fines ratio of from 1:1 to 5:1. Often the sand to fines ratio may be from 1:1 to 4:1, such as from 2:1 to 3:1. The aqueous slurry may have a fines solids content of from 10% to 45%, by total weight of the aqueous slurry.
The invention is of applicability where the aqueous slurry is derived from an oil sands fluid fines tailings (FFT), thickened fine tailings (ThFT) or a mature fines tailings (MFT). Fluid fine tailings (FFT) are generally understood to mean a liquid suspension of oil sands fine tailings or fines dominated tailings in water, with a solids content greater than 2%
but less than the solids content corresponding to the Liquid Limit. Mature fines tailings are understood to be a more specific category of fluid fine tailings with a sand to fines ratio of less than 0.3 and a solids content typically greater than 30%. Thin fine tails (TFT) may be understood to be a category of fluid fine tailings with a sand to fines ratio of less than 0.3 and a solids content typically between 15 and 30%. Thickened fine tailings (ThFT) mean fluid fine tailings (FFT) or thin fine tailings (TFT) that have been thickened by removal of some of the aqueous content. However, the solids content of such thickened fine tailings would not be above the liquid limit and therefore remain fluid.
Typically, the aqueous slurry comprises from 10% to 70% clay particles based on the total weight of solids. In general, the clay particles tend to be predominantly kaolinite and illite.
The clay frequently also contains smectite and chlorite. The proportions of the clay components of oil sands clays in marine deposits tend to vary according to depth within the deposit. Generally, illite species slightly dominates in the top end of the deposits. The smectite species are generally interlayered with either the kaolinite or illite species, and this tends to induce additional separation of particles.

Date Recue/Date Received 2022-03-14 BASF SE

Although the method of the present invention is particularly suited to the treatment of tailings derived from oil sands, especially mature fines tailings (MFT). Suitably, the method may be used to treat other oil sands tailings slurries, for instance whole tailings (WT), composite tailings (CT), fluid fines tailings (FFT), thin fine tailings (TFT) and/or thickened fines tailings (ThFT). The method may also be employed to treat other mineral derived tailings slurries.
Suitably, the tailings slurry (TS) may comprise phosphate slimes, gold slimes or wastes from diamond processing. Typically, this may include any of the group consisting of coal fines tailings, mineral sands tailings, red mud (alumina Bayer process tailings), zinc ore tailings, lead ore tailings, copper ore tailings, silver ore tailings, uranium ore tailings, nickel ore tailings and iron ore tailings.
In the method of the present invention the tailings slurry (TS) flows as at least one first mass flow (MS1) to at least one first mixing region (MR1). Within the at least one first mixing region (MR1) it is equipped with at least one agitation means (AG1) to facilitate the mixing and distribution of the tailings slurry (TS). The tailings slurry (TS) would optionally then be transferred to at least one second mixing region (MR2) which is equipped with at least one agitation means (AG2) which further facilitates the mixing distribution of the tailings slurry (TS). Subsequently, the tailings slurry may exit the at least one first mixing region (MR1) and/or optionally at least one second mixing region (MR2) as at least one conditioned tailings stream (CTR). Nevertheless, the tailings slurry (TS) flowing through the at least one first mixing region (MR1) and/or at least one second mixing region (MR2) may pass through one or more further mixing regions before exiting as at least one conditioned tailings stream (CTR).
The at least one containment may be any entity which has a boundary wall and able to contain the tailings slurry (TS). This may be for instance a vessel or a pipeline or other conduit but preferably the containment is a vessel. The vessel may for instance be a stirred tank reactor or analogous entity.
Preferably the at least one containment, preferably vessel, comprises a multiplicity of chambers and in which the tailings slurry (TS) progresses through each of the respective chambers in succession.
Typically, each of the at least one first mixing region (MR1) and/or optional at least one second mixing region (MR2) each independently comprises one or more chambers.
The tailings slurry (TS) should progress through each of the respective chambers in succession.

Date Recue/Date Received 2022-03-14 BASF SE

The agitation means (AGI) may be provided by at least one agitation element in one or more chambers of the first mixing region (MRI). Agitation means (AG2) may provide at least one agitation element in one or more chambers of the second mixing region (MR2). The at least one agitation means (AGI) and/or at least one agitation means (AG2) may be any means that facilitates agitation within the at least one first mixing region (MRI) and/or at least one second mixing region (MR2). The agitation means (AGI) and/or agitation means (AG2) may each independently be one or more static mixers, one or more active or dynamic mixers or even combinations of static and active or dynamic mixers. Although agitation means (AGI) may comprise at least one static mixer it is preferred that agitation means (AGI) comprises at least one dynamic mixer or a combination of at least one dynamic mixer and at least one static mixer. Agitation means (AG2) likewise may comprise at least one static mixer although it is preferred that agitation means (AG2) comprises at least one dynamic mixer or a combination of at least one dynamic mixer and at least one static mixer.
Static mixers generally contain static elements which due to their shape and orientation facilitate the mixing and distribution of the tailings stream (TS) within this respective mixing region as the tailings stream (TS) flows through or by the elements of the static mixer.
The degree of agitation provided by the respective agitation means (AG 1) and where present (AG2) can be defined as the amount of disturbance of the flow patterns that would otherwise be established by normal flow of the tailings slurry (TS) through the respective containment for each of the at least one first mixing region (MRI) and where present the at least one second mixing region (MR2).
By normal flow of the tailings slurry (TS) through the respective containment we mean what the flow pattern would have been in the absence of the respective agitation means. Degree of agitation may be considered a relative term and varying the degree of agitation will usually depend upon the specific agitation means employed and the environment containing the respective mixing region and the properties of the particular tailings slurry (TS). The exact initial settings for the respective agitation means can be established by routine experimentation and thereafter adjusting the settings can be carried out to achieve optimal degree of agitation in response to the at least one item of information (11).
The method according to the present invention desirably employs two types of control: a coarse control; and a fine control.
The coarse control relates to the initial setting for the respective dose settings for each of the clay decoagulant reagent (DGR) and the flocculent (F) and the respective rates of mixing for Date Recue/Date Received 2022-03-14 BASF SE

the respective means of agitation ((AG 1) and/or (AG2)) as applicable; and the resetting of the respective parameters according to the at least one item of information (II). Thus, the coarse control predominates in response to the at least one item of information (11) at the initial start-up of the process of the inventive method and where there are significant and rapid changes in the tailings slurry (TS), especially of the first mass flow (MS1). These significant and rapid changes to the tailings slurry (TS) may for instance be volumetric control, sand to fines ratio (SFR), clay content solids content, specific gravity and/or the flow rate.
The fine control relates to the method operation which predominates when the at least one item of information (11) is stable, i.e. the (II) data is in steady-state or only minor fluctuations occur within the detected data. Typically, this would mean that only small incremental changes are made in the control. Thus, on the basis of the at least one item of information (15) only small incremental changes would be made to the dose of the flocculent (F) and/or dose of the clay decoagulant reagent (DGR). Similarly in the case of the first aspect of the invention the adjustment to the rate of agitation provided by the at least one agitation means (AGI) in response to the at least one item of information (13) would tend to be only small incremental changes while the adjustment of the rate of agitation provided by the at least one agitation means (AG2) in response to the combination of at least one item of information (14) and at least one item of information (15) would also tend to be only small incremental changes. In a similar fashion in the case of the second aspect of the invention the adjustment to the rate of agitation provided by the at least one agitation means (AG 1) in response to the combination of at least one item of information (13) and at least one item of information (15) would tend to be small incremental changes.
In a preferred embodiment where at least one item of information (12) is employed it would also be part of the fine control. Thus, the combination of at least one item of information (12) and the at least one item of information (13) would tend to be used to make only small incremental changes to the rate of mixing provided by the at least one agitation means (AG 1). In addition, the combination of at least one item of information (12) and the at least one item of information (15) would tend to be used to make only small incremental changes to the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F).
In the case of static mixers, variations in degree of agitation may be achieved when using a static mixer by varying the flow rate of the tailings stream (TS). It is also possible to enhance the static mixer by providing the static mixer at least one element with the ability to move or change position. The movement of such elements of the static mixer may be to extend the Date Recue/Date Received 2022-03-14 BASF SE

element to create a larger contact surface and/or change orientation of the element both of which may induce a higher degree of agitation. Such movement of static mixer elements may be achieved by the action of an actuator. In this case when the respective at least one of each of agitation means (AG1) and/or (AG2) comprise static mixer(s) the degree of agitation associated with the agitation means relates to the extent of fluid mixing/turbulence generated as the tailings slurry (TS) flows through the static mixer.
Preferably the at least one first mixing region (MR1) and/or at least one second mixing region (MR2) comprise one or more dynamic mixer(s). Dynamic mixers typically have rotating elements and can operate at variable speeds. When the at least one first mixing region (MR1) and/or at least one second mixing region (MR2) comprise dynamic mixer(s) the dynamic mixing elements of the dynamic mixers may represent the at least one agitation means (AG1) and/or at least one agitation means (AG2) respectively. The degree of agitation associated with dynamic mixers may be regarded as the rate at which the moving elements of the agitation means move. In most cases the agitation means comprises rotating elements. This is typically when the respective at least one agitation means (AG1) and/or at least one agitation means (AG2) is/are dynamic mixer(s). In this case the degree of agitation associated with the agitation means may be the rate or speed at which the rotating elements move. This may be varied by controlling the rotating speed, for instance in terms of revolutions per minute (rpm) or reciprocal seconds. The exact speed of rotation will depend on the shape, length and diameter of rotating elements in addition to the environment of the respective mixing region and composition of the tailings stream (TS) being mixed. This may be determined by conducting routine mixing tests to establish initial rotation speeds for the respective at least one agitation means (AG1) and at least one agitation means (AG2).
The required degree of agitation could be determined by measuring parameters related to the flow characteristics in the respective at least one mixing region (MR1) and/or at least one mixing region (MR2). This could be for instance by measuring the respective fluidity measurements (FM1), suitably output pressure measurements (OPM1) and/or fluidity measurements (FM2), suitably output pressure measurements (OPM2). The degree of agitation may be maintained or varied in response to the respective mixing or flow characteristics within the respective at least one first mixing region (MR1) and/or at least one second mixing region (MR2), for instance in response to the respective fluidity measurements (FM1), suitably output pressure measurements (OPM1) and/or fluidity measurements (FM2), suitably output pressure measurements (OPM2).

Date Recue/Date Received 2022-03-14 BASF SE

Varying the degree of agitation may, for instance, be achieved by adjusting the flow rate through the static mixer as required. Alternatively, where the static mixer has been enhanced by including elements that extend or change orientation, as given herein, the degree of agitation may be varied by adjusting the degree of extension and/or orientation of the respective elements by means of one or more actuators. In this case, the degree of agitation may be altered by adjusting the elements in combination with adjusting the flow rate of the tailings slurry (TS).
In accordance with the present invention the initial rate of mixing provided by the at least one agitation means (AGI) is set or reset in response to the at least one item of information (11) according to predefined conditions for the tailings slurry (TS).
The degree of agitation associated with the at least one first agitation means (AGI) may be maintained or changed in response to the at least one item of information (13) in the first aspect of the invention where the method comprises at least one first mixing region (MRI) and at least one second mixing region (MR2). Desirably where the at least one item of information (13) indicates that the fluidity measurements (FM1), suitably output pressure measurements (OPMI), are not optimal the rate of mixing provided by the at least one agitation means (AGI) would be adjusted by increasing or decreasing. In a preferred scenario where the at least one item of information (12) is included, where the combination of at least one item of information (13) concerning the fluidity measurements (FM1), suitably output pressure measurements (OPMI), and at least one item of information (12) concerning the structural data for the second mass flow (M52) indicate that conditions are not optimal then the rate of mixing provided by the at least one agitation means (AGI) would be adjusted by increasing or decreasing.
In accordance with the present invention the initial rate of mixing provided by the at least agitation means (AG2) is set or reset in response to the at least one item of information (11) according to predefined conditions for the tailings slurry (TS).
The degree of agitation associated with the at least one agitation means (AG2) may be maintained or changed in response to the combination of the at least one item of information (14) and the at least one item of information (15). Where the combination of the at least one item of information (14) and the at least one item of information (15) indicates that the differential in at least one fluidity measurements (FM2), suitably output pressure measurements (OPM2), is insufficient and/or the tailings slurry (TS) flowing from the at least one second mixing region (MR2) is under-mixed, the rate of mixing provided by the at least Date Recue/Date Received 2022-03-14 BASF SE

one agitation means (AG2) would be increased. Desirably where the combination of the at least one item of information (14) and the at least one item of information (15) indicates respectively that the fluidity measurements (FM2), suitably output pressure measurements (OPM2), and/or the conditioned tailings stream (CTR) or components separated therefrom i.e. the process operation is/are not optimal, the rate of mixing provided by the at least one agitation means (AG2) would be adjusted by increasing or decreasing to bring the operation of the method into a more optimal performance.
In the second aspect of the present invention where the method does not comprise the second mixing region (MR2) the degree of agitation associated with the at least one agitation means (AG1) may be maintained or changed in response to the combination of the at least one item of information (13) and the at least one item of information (15).
Desirably where the combination of the at least one item of information (13) and the at least one item of information (15) indicates respectively that the fluidity measurements (FM1), suitably output pressure measurements (OPM1), and/or the conditioned tailings stream (CTR) or components separated therefrom i.e. the process operation is/are not optimal, the rate of mixing provided by the at least one agitation means (AG1) would be adjusted by increasing or decreasing to bring the operation of the method into a more optimal performance.
In accordance with this aspect of the method of the present invention where the at least one first mixing region (MR1) comprises a dynamic mixer, the speed of the rotating elements can be controlled thus representing the control of the speed of the at least one agitation means (AG1). Similarly, where the at least one second mixing region (MR2) comprises a dynamic mixer, the speed of the rotating elements can be controlled thus representing the control of the speed of the at least one agitation means (AG2).
Preferably, both the at least one first mixing region (MR1) and the at least one second mixing region (MR2) comprise dynamic mixers each representing at least one agitation means (AG1) and at least one agitation means (AG2) respectively.
The at least one first and the at least one second mixing regions (MR1) and (MR2) would preferably each comprise at least one chamber, but often may each contain a multiplicity of chambers. Each chamber may be separated by orifice plates and/or baffles. The size and exact position of the orifice plates and/or baffles may be chosen so as to facilitate the .. required level of mixing within each chamber.

Date Recue/Date Received 2022-03-14 BASF SE

In one preferred embodiment of the invention the at least one first mixing region (MR1) and the at least one second mixing region (MR2) each independently comprises one or more chambers in which the tailings slurry (TS) progresses through each of the respective chambers in succession. The at least one agitation means (AG1) should provide at least one agitation element in the one or more chambers of the at least one first mixing region (MR1) and the at least one agitation means (AG2) provides at least one agitation element in the one or more chambers of the at least one second mixing region (MR2). In this preferred embodiment, more preferably the at least one first mixing region (MR1) and/or the at least one second mixing region (MR2) is/are dynamic mixer(s). More preferably still both the at least one first mixing region (MR1) and/or at least one second mixing region (MR2) is/are dynamic mixer(s). Suitably, the respective degree of agitation associated with at least one agitation means (AG1) and/or at least one agitation means (AG2) can be varied and controlled independently.
In one preferred embodiment, the at least one first mixing region (MR1) and the at least one second mixing region (MR2) may be contained in a single containment, suitably a single vessel. It is desirable to ensure that the respective mixing regions (MR1) and (MR2) are maintained substantially independent of one another. Therefore, it would be usually desirable to ensure that the respective mixing regions (MR1) and (MR2) have at least some degree of separation. This may be by means of one or more baffles but preferably the respective mixing regions (MR1) and (MR2) are separated by orifice plate. The orifice plate may have an orifice placed centrally or if desired located off centre, for instance midway between the centre of the containment, suitably the centre of the vessel and the wall of the containment, suitably the wall of the vessel. Preferably, the orifice is an annular opening with a diameter sufficiently large to allow the flow of tailings slurry from the at least one first mixing region (MR1) into the at least one second mixing region (MR2). The orifice may also accommodate a component of the at least one agitation means (AG2), for instance the shaft on which the mixing elements for the at least one agitation means (AG2) are mounted where the agitation means is driven by a motor, for instance above the vessel.
Alternatively, the at least one agitation means (AG2) may be driven by a motor mounted beneath the vessel with the agitation means mounted in an inverted orientation. In this alternative form it would not be necessary for the orifice to accommodate any part of the at least one agitation means (AG2).
In a further alternative form, the at least one first mixing region (MR1) and the at least one second mixing region (MR2) are separated by a constriction to the containment.
In such a scenario the respective mixing regions (MR1) and (MR2) would be located within a single Date Recue/Date Received 2022-03-14 BASF SE

containment, such as vessel, pipe or other conduit, and the constriction could be, for instance, a narrowing of the containment wall to form a smaller diameter than the rest of the containment. Typically, where this containment is a vessel, the constriction could be in the form of a tube or pipe leading from the at least one first mixing region (MRI) to the at least one second mixing region (MR2). Similarly, where this containment is itself a pipe, or other conduit, the constriction may be a narrower section of pipe, or tube, connecting the respective mixing regions (MRI) and (MR2). It would also be possible to mount the at least one instrument for gathering the at least one item of information (12) in the constriction.
Suitably, constriction could be a pipe sensor which contains the sensor, which would typically be integral to the pipe sensor, and serves to convey the tailings stream (TS) as at least one second mass flow (M52) from the at least one first mixing region (MRI) to the at least one second mixing region (MR2). Suitably changes in the structure of the at least one second mass flow may be obtained through at least one instrument which gathers information selected from at least one item of the group consisting of tomography, imaging, .. vibration and acoustics. Typically, such at least one instrument that is mounted in the constriction may be an ultrasonic analyser, an accelerometer or a vibrometer for gathering the at least one item of information (12) but could employ any of the other techniques mentioned herein below. As above a particularly suitable instrument for gathering the at least one item of information (12) is an accelerometer. Another suitable instrument for gathering at .. least one item of information (12) may for instance be a vibrometer.
In one preferred embodiment the at least one first mixing region (MRI) and the at least one second mixing region (MR2) are contained in separate vessels.
Desirably, the at least one item of information (11) associated with the at least one first mass flow (MS1) is selected from at least one of the group consisting of the sand to fines ratio (SFR); the solids content; the clay content; the specific gravity and the flow rate.
The sand to fines ratio (SFR) of the tailings slurry (TS) may be determined by an in-line particle size analyser which measures the particle size distribution and then calculates the sand to fines ratio (SFR). Such in-line particle size analyser may involve ultrasonic attenuation (e.g. employing an ultrasonic analyser), optical image analysis methods or mechanical measurement. Other techniques include laser diffraction which would give a volumetric particle size analysis without external calibration. Such instruments include an .. online laser scatter particle size analyser, which are available commercially. Other suitable techniques include Background Gamma Detectors, which is an instrument for passively detecting gamma radiation. In this case the gamma radiation would be emitted from Date Recue/Date Received 2022-03-14 BASF SE

potassium4 (K40) present in the clay. This will give an indication of the amount of clay present in the tailings slurry (TS). It may be desirable to use a combination of instruments detecting information for the tailings slurry (TS) to deduce the sand to fines ratio (SFR). This may, for instance be a combination of any of density analysers, particle size analysers, flow detectors or gamma detectors, which based on known properties of the tailings slurry may allow such deduction of the sand to fines ratio (SFR). Alternatively, the use of data from a Background Gamma Detector in combination with other data could be used to establish the sand to fines ratio (SFR). Further techniques for gathering the at least one item of information (11) include tomography. This could be specifically EMT (Electro-Magnetic Tomography) and/or ERT (Electro-Resistive Tomography). Tomography, for instance EMT
or ERT, could be used alone, or more likely in combination with other data gathered regarding the at least one item of information (11), for instance as described herein. Such data may be processed by a logic controller, especially combined with Machine Learning or Artificial Intelligence (Al).
The solids content of the tailings slurry (TS) may be determined by an in-line slurry analyser, for instance equipment which uses ultrasonic signals to give an online continuous measurement of the solids content over a range of solid contents. Such products include the In-Line Slurry Analyser which are available commercially.
The flow rate of the tailings slurry (TS) may be determined by an in-line flow rate device adapted to measure the flow rate of mineral slurries. Some devices include ultrasonic flowmeters, Coriolis flowmeters and magnetic flowmeters (MagFlow). Such devices can measure both mass flow and volume flow and can be used to determine density (SG). Mass flowmeters have been shown to give reliable data. It may be desirable to use a combination of mass flow metres with other instruments gathering data on the tailings slurry (TS), for instance in the at least one first mass flow (MSI) to determine the flow rate.
Such data may be processed by a logic controller, especially combined with Machine Learning or Artificial Intelligence (Al).
The at least one item of information (13) is associated with the first fluidity measurements (FM1). The first fluidity measurements (FM1) may for instance be pressure measurements, for instance as first output pressure measurements (OPMI). The first fluidity measurements (FM1) may employ other types of sensors, for instance sensors that detect vibration or acoustics. Suitably the sensor may be a vibrometer. The first fluidity measurements (FM1), suitably as first output pressure measurements (OPMI), may be determined by at least one sensor which is adapted to measure fluctuations in the tailings slurry (TS), which in the case Date Recue/Date Received 2022-03-14 BASF SE

of first output pressure measurements may be fluctuations in pressure occurring in the at least one first mixing region (MR1). Specifically, the sensors would measure any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MR1) to exiting the at least one first mixing region (MR1). In the case of first output pressure measurements (OPM1) this would be the change in the pressure as the tailings slurry (TS) progresses through the at least one first mixing region (MR1). Desirably the at least one first mixing region (MR1) may be contained by a wall, for instance the vessel wall, and the fluidity measurements would be determined by at least one sensor which is adapted to detect pressures, vibration or acoustics within the at least one first mixing region (MR1). Suitably the fluidity measurements would be output pressure measurements that would be determined by at least one sensor which is adapted to detect pressures and/or variations in pressure within the at least one first mixing region (MR1). This may desirably be achieved by detecting pressure measurements and/or pressure variations within the at least one first mixing region (MR1) within proximity of the wall of the vessel and/or containing the at least one first mixing region (MR1). Suitable instruments for detecting the output pressure measurements (OPM1) include Pressure Transducers. Such instruments are readily available commercially. Typically, such Pressure Transducers may consist of a ceramic pressure sensing diaphragm, the inner surface of which is in contact with the contents of the at least one first mixing region (MR1), i.e. tailings slurry (TS), while the outer surface is exposed to atmosphere. Alternatively, the inner surface of the ceramic pressure sensing diaphragm may be covered by a sheath or sleeve in order to protect its surface from abrasion by the solids in the tailings slurry (TS). As the pressure changes occur in the at least one first mixing region (MR1) the diaphragm will move with pressure pulse peaks, and the transducer transmit signals which can be collected.
It may be desirable to employ a multiplicity of suitable sensors for determining fluidity measurements (FM1). For measuring output pressure measurements (OPM1) may be desirable to employ a multiplicity of suitable pressure measurement sensors, for instance Pressure Transducers, for detecting and collecting the output pressure measurements (OPM1) within the first mixing region. For instance, pressure measurement sensors, for instance Pressure Transducers, may be mounted around the at least one first mixing region (MR1), at each stage where the at least one agitation means (AG1) is/are located, for instance at each stage where the one or more stators of the at least one agitation means (AG1) is/are located. It may also be desirable to position the pressure measurement sensors, for instance Pressure Transducers, around the inlet(s) and/or outlet(s) of the at least one first mixing region (MR1) Date Recue/Date Received 2022-03-14 BASF SE

Analogously, the at least one item of information (14) is associated with the second fluidity measurements (FM2). The second fluidity measurements (FM2) may for instance be pressure measurements, for instance as second output pressure measurements (OPM2).
The second fluidity measurements (FM2) may employ other types of sensors, for instance sensors that detect vibration or acoustics. Suitably the sensor may be a vibrometer. The at least one second fluidity measurements (FM2) suitably as second output pressure measurements (OPM2), may be determined by at least one sensor which is adapted to measure fluctuations in the tailings slurry (TS), which in the case of second output pressure measurements (OPM2) may be fluctuations in pressure occurring in the at least one second mixing region (MR2). Specifically, the sensors would measure any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR1) to exiting the at least one second mixing region (MR2). In the case of second output pressure measurements (OPM2) this would be the change in pressure as the tailings slurry (TS) progresses through the at least one second mixing region (MR2). Desirably the at least one second mixing region (MR2) may be contained by a wall, for instance the vessel wall or pipeline wall, and the fluidity measurements will be determined by at least one sensor which is adapted to detect pressures, vibration or acoustics within the at least one second mixing region (MR2). Suitably the fluidity measurements would be output pressure measurements that would be determined by at least one sensor which is adapted to detect pressures and/or variations in pressure within the at least one second mixing region (MR2).
This may desirably be achieved by detecting pressure measurements and/or pressure variations within the at least one second mixing region (MR2) within proximity of the wall of the vessel and/or containing the second mixing region (MR2). Suitable instruments for detecting the output pressure measurements (OPM2) include Pressure Transducers analogously to the instruments and analogous operation employed regarding the output pressure measurements (OPM1) and applied analogously regarding the at least one second mixing region (MR2) and the associated at least one agitation means (AG2). Typically, such Pressure Transducers may consist of a ceramic pressure sensing diaphragm, the inner surface of which is in contact with the contents of the at least one second mixing region (MR2), i.e. tailings slurry (TS), while the outer surface is exposed to atmosphere.
Alternatively, the inner surface of the ceramic pressure sensing diaphragm may be covered by a sheath or sleeve in order to protect its surface from abrasion by the solids in the tailings slurry (TS). As the pressure changes occur in the at least one second mixing region (MR2) the diaphragm will move with pressure pulse peaks, and the transducer transmit signals which can be collected.

Date Recue/Date Received 2022-03-14 BASF SE

It may be desirable to employ a multiplicity of suitable sensors for determining fluidity measurements (FM2). For measuring output pressure measurements (OPM2) it may be desirable to employ a multiplicity of suitable pressure measurement sensors, for instance Pressure Transducers, for detecting and collecting the output pressure measurements (OPM2) within the second mixing region (MR2). For instance, pressure measurement sensors, for instance Pressure Transducers, may be mounted around the at least one second mixing region (MR2), at each stage where the at least one agitation means (AG2) is/are located, for instance at each stage where the one or more stators of the at least one agitation means (AG2) is located. It may also be desirable to position the pressure measurement sensors, for instance Pressure Transducers, around the inlet(s) and/or outlet(s) of the at least one second mixing region (MR2).
As given above, the output pressure measurements (OPM1) and (OPM2) should give an indication of the mixing and/or flow characteristics of the tailings slurry (TS) in each of the at least one first and at least one second mixing regions, respectively. Further, the output pressure measurements (OPM1) and (OPM2) may give information on the distribution of the solids throughout each of the respective at least one first mixing region (MR1) and at least one second mixing region (MR2). The output pressure measurements may focus on the flow characteristics of the tailings slurry (TS) in the vicinity of the periphery of the respective mixing regions (MR1) and (MR2), for instance in close proximity to the vessel wall or wall containing the respective mixing regions, such as pipeline wall when the respective mixing region is contained in a pipeline. These first and second output measurements (OPM1) and (OPM2) may desirably indicate whether the flow within the respective mixing regions are laminar flow or non-laminar flow. Non-laminar flow may include turbulent flow.
This may give an indication of the state of the particles contained within the tailings slurry (TS), for instance whether the particles contained therein are agglomerated or freely distributed.
Desirably the at least one item of information (I5a) associated with the conditioned tailings stream (CTR), may for instance be selected from at least one of the group consisting of vibration, acoustics, tomography and measurements associated with the separation.
Tomography could be specifically EMT (Electro-Magnetic Tomography) and/or ERT
(Electro-Resistive Tomography). At least one of the items of information (I5a) may be detection of whether the conditioned tailings stream (CTR) is exhibiting turbulent flow or substantially non-turbulent flow. Non-turbulent flow would include laminar flow.
Vibration and/or acoustic measurements are well known and can be used to detect vibration and acoustic frequencies. Typically, such sensors may employ sonic signals which can give Date Recue/Date Received 2022-03-14 BASF SE

information on the flow characteristics of the conditioned tailings stream (CTR). The tomography of the conditioned tailings stream (CTR) can be determined by passing wave signals through the conditioned tailings medium (CTR) as a flowing liquid. A
picture can be built up of the level of solids flowing through a pipeline and the flow characteristics. This may .. be achieved by use of nuclear sources, for instance gamma densitometers although preferably by employing electrical conductivity and contrasting electrical conductivity between solids and the flowing liquid of the conditioned tailings stream (CTR). It may be desirable to use targeted vibration and/or acoustic data which can enable the detection of the degree of solids liquid separation in the conditioned tailings stream (CTR). The inventors believe that as the degree of flocculated solids and free liquid varies so will the vibration or acoustic signature generated as the fluid flows through the pipe.
Preferably items of information (I5a) on the conditioned tailings stream (CTR) may be determined by employing an accelerometer. Such accelerometer may employ a frequency span suitable for a conditioned tailings stream (CTR). Generally, such a frequency scan may be in the range from 0 to 10 kHz.
Desirably, the at least one item of information (I5b) associated with the conditioned tailings stream (CTR) and employs measurements associated with the separation characteristics.
This could relate to the separation rate or speed with which the conditioned tailings stream (CTR) can be separated into the constituent components solids and liquid. The information could also relate to the turbidity of the separated liquid, which would give an indication of the efficiency of the separation process in regard to the amount of solids, particularly fines, distributed throughout the separated liquid. Other items of information (I5b) could include the solids content of the solid material separated or indeed the moisture content of the solid material separated, which would give an indication of the amount of residual liquid remaining in the separated solids fraction. Thus, the measurements associated with the separation may be selected from at least one of the group consisting of separation rate, turbidity of the liquor separated from the conditioned tailings stream (CTR) solids content of the solid material separated from the conditioned tailings stream (CTR) and moisture content of the solid material separated from the conditioned tailings stream (CTR).
In the present invention the initial dose of the clay decoagulant reagent (DGR) should be set in response to the at least one item of information (11) according to predefined conditions for the tailings slurry (TS). The at least one item of information (11) may also be employed to set the initial point of addition for the clay decoagulant reagent (DGR) for the tailings slurry (TS).
The dose and/or the point or points of addition of the clay decoagulant reagent (DGR) can Date Recue/Date Received 2022-03-14 BASF SE

be reset in response to the at least one item of information (11). Suitably this may be when the at least one item of information (11) indicates that the composition of the tailings slurry (TS) has changed significantly so as to require a different dose of the clay decoagulant reagent (DGR). Resetting in this context would mean setting the dose of the clay decoagulant reagent (DGR) to a dose different from the initial dose based on the at least one item of information (II) and predefined conditions for the tailings slurry (TS). This may be as a result of the clay or fines content of the tailings slurry (TS) significantly changing i.e.
increasing or decreasing. Generally, a higher clay or fines content for a particular tailings slurry (TS), may require a higher dose of the clay decoagulant reagent (DGR) and a lower clay or fines content for a particular tailings slurry (TS), may require a lower dose of the clay decoagulant reagent (DGR). Alternatively, this resetting may be resetting dose of clay decoagulant reagent (DGR) to the initial setting when the dose as varied has become significantly different from the initial dose where the composition, for instance clay or fines content, of the tailings slurry (TS) which has not significantly changed.
The dose of clay decoagulant reagent (DGR) may be maintained or varied in response to the at least one item of information (15). Where the at least one item of information (15) indicates that the level of clay in a coagulated state is above an acceptable range that tailings slurry (TS) according to said predefined conditions the dose of clay decoagulant reagent (DGR) can be increased. Where the at least one item of information (15) indicates that the optimum level of clay decoagulation for that tailings slurry (TS) has been exceeded the dose of clay decoagulant reagent (DGR) can be decreased. The dose of clay decoagulant reagent (DGR) may be increased at the same time as increasing the dose of flocculent (F) in response to the at least one item of information (15) where the at least one conditioned tailings stream (CTR) appears to be under flocculated. The dose of clay decoagulant reagent (DGR) may be decreased at the same time as decreasing the dose of flocculent (F) in response to the at least one item of information (15) where the at least one conditioned tailings stream (CTR) appears to be over-flocculated. This item of information (15) may be information (15a) relating to the at least one conditioned tailings stream (CTR); and/or (I5b) relating to components of the conditioned tailings stream (CTR) selected from at least one of the group selected from solid/liquid separation rate, volume of released liquid, turbidity of released liquid and moisture content of separated solids, in accordance with the detailed information concerning the at least one item of information (15) described herein.
In the present invention the initial dose of the flocculent (F) should be set in response to the at least one item of information (11) according to predefined conditions for the tailings slurry (TS). The at least one item of information (11) may also be employed to set the initial point of Date Recue/Date Received 2022-03-14 BASF SE

addition for the flocculent (F) for the tailings slurry (TS). The dose and/or point or points of addition of the flocculent (F) may also be reset in response to the at least one item of information (11) Suitably this may be when the at least one information (II) indicates that the composition of the tailings slurry (TS) has changed significantly so as to require a different dose of the flocculent (F). Resetting in this context would mean setting the dose to the flocculent (F) to a dose different from the initial dose based on the at least one item of information (11) and predefined conditions for the tailings slurry (TS). This may be as a result of the clay or fines content of the tailings slurry (TS) significantly changing i.e. increasing or decreasing. Alternatively, this resetting may be resetting dose of flocculent (F) to the initial setting when the dose as varied has become significantly different from the initial dose where the composition of the tailings slurry (TS) which has not significantly changed.
The flocculent (F) dose may be maintained or changed in response to the at least one item of information (15). Where the at least one item of information (15) indicates from the conditioned tailings stream (CTR) or components thereof that the dose of flocculent (F) is below the optimum dose, in response to this at least one item of information (15) the dose of flocculent (F) should be increased. Where the at least one item of information (15) indicates from the conditioned tailings stream (CTR) or components thereof that the dose of flocculent (F) is greater than the optimum dose, in response to this at least one item of information (15) the dose of flocculent (F) should be decreased. The item of information (15) useful for indicating whether the dose of flocculent (F) should be changed may be (15a) associated with changes to the structure of the conditioned tailings stream (CTR) as described herein. If the information on the structure of the conditioned tailings stream (CTR) indicates under-flocculation then the dose of flocculent (F) can be increased and if the information on the structure of the conditioned tailings stream (CTR) indicates over-flocculation then the dose of flocculent (F) can be decreased. The item of information (15) useful for indicating whether the dose of flocculent (F) should be changed may be (I5b) associated with changes in at least one of the group selected from solid/liquid separation rate, volume of released liquid, turbidity of released liquid and moisture content of separated solids as described herein. For instance, this could be in response to the turbidity measurements/fines solids measurements in the water released from the dewatering of the conditioned tailings stream (CTR). Where such turbidity measurements or fines solids measurements in the released water exceed an acceptable limit, the dose of flocculent (F) may be increased. Where such information on the separated solids, for instance moisture content of cake solids, shows that that the moisture content exceeds an acceptable limit, the dose of flocculent (F) may be increased. Where the solid/liquid separation rate and/or the volume of released liquid is below an acceptable limit, the dose of flocculent (F) may be increased. Where the dose of the flocculent (F) has been Date Recue/Date Received 2022-03-14 BASF SE

raised to a point where no further improvement is observed from any of the at least one item of information (I5b) data the dose of flocculent may be reduced. The dose of flocculent (F) may be maintained, increased or decreased independently of the dose of the clay decoagulant reagent (DGR) or may be desirable that the dose of the clay decoagulant reagent (DGR) may be increased or decreased simultaneously with respectively increasing or decreasing the flocculent (F) dose.
In the desirable embodiment where at least one item of information (12) is employed, the combination of the at least one item of information (15) and at least one item of information (12) may be used to vary the point or points of addition for each of the clay decoagulant reagent (DGR) and/or the flocculent (F), suitably according to predefined conditions for the tailings slurry (TS). Where the at least one item of information (15) and at least one item of information (12) in combination indicate that the level of clay in a coagulated state is above an acceptable range that tailings slurry (TS) according to said predefined conditions the dose of clay decoagulant reagent (DGR) can be increased. Where the at least one item of information (15) and the at least one item of information (12) in combination indicate that the optimum level of clay decoagulation for that tailings slurry (TS) has been exceeded the dose of clay decoagulant reagent (DGR) can be decreased. Where the at least one item of information (15) and the at least one item of information (12) in combination indicate that the conditioned tailings stream (CTR) and/or second mass flow (M52) is/are under-flocculated according to predefined settings for the tailings slurry (TS) the dose of flocculent (F) can be increased. Where the at least one item of information (15) and at least one item of information (12) in combination indicate that the conditioned tailings stream (CTR) and/or second mass flow (M52) is/are over-flocculated according to predefined settings for the tailings slurry (TS) the dose of flocculent (F) can be decreased.
It may be desirable to divide the tailings slurry (TS) into separate mass flows (MS1) and treat each separate mass flow in accordance with the present invention, albeit separately. This may present the advantage that large volumes of tailings can be treated in separate small scale process operations each running in parallel. This offers the advantage that one single large-scale device and large-scale process would not be necessary avoiding the need for scale up. In addition, each divided mass flow can be dealt with independently and in the case of any unforeseen process stoppage on any one line the whole tailings treatment operation would not need to be shut down. It is envisaged that each divided stream of the tailings slurry (TS) would be treated separately according to the process of the invention each in parallel. Alternatively, it may be desirable to recombine the tailings slurry, for Date Recue/Date Received 2022-03-14 BASF SE

instance in one or other of the mixing regions or significantly combining the separate conditioned tailings stream (CTR) into a combined conditioned tailings stream (CCTR).
The point of addition of the clay decoagulant reagent (DGR) added to the tailings stream (TS) may be increased to more than one point of addition in cases where the dose of the clay decoagulant reagent (DGR) is increased. This will enable greater integration of the clay decoagulant reagent (DGR) into the tailings slurry (TS). Thus, this can be in response to the increased dose of clay decoagulant reagent (DGR) determined as a result of the increased clay content measured in the tailings slurry (TS) in the first mass flow (MSI) as at least one .. item of information (II). Nevertheless, the point or points of addition of the clay decoagulant reagent (DGR) added to the tailings slurry (TS) will normally be at a point or points before the addition of the dosing of the flocculent (F). Depending upon the configuration of the dosing points an optional dosing points of the clay decoagulant reagent (DGR) in relation to the dosing point or dosing points of the flocculent (F) it may be necessary to adjust a dosing .. of the clay decoagulant reagent (DGR) to an earlier point of addition where a greater spread of dosing points of the flocculent (F) is required.
The point of addition of the flocculent (F) added to the tailings slurry (TS) may be increased to more than one point of addition in cases where the dose of the flocculent (F) is increased.
This will facilitate greater integration of the flocculent (F) into the tailings slurry (TS). Thus, this can be in response to the increased dose of flocculent (F) for instance determined as a result of the measured parameters on the conditioned tailings stream (CTR) as at least one item of information (15). The flocculent (F) may be dosed into one or more of the first mass flow (MS1), the first mixing region (MRI), the second mass flow (M52) or the second mixing region (MR2) and it may be desirable that the dosing regime applies doses of the flocculent in any one or any number of these locations. Preferably, when the number of dosing points is increased it is increased by increasing the dosing points into one or more of these 4 categories. For instance, preferably the flocculent (F) is dosed into the first mixing region (MRI) and by increasing the number of dosing points this may be 2 or more dosing points in .. the first mixing region (MRI).
Controlling any of the parameters described in the description of the invention and more precise embodiments thereof provided herein in response to the respective items of information as given herein, may be achieved by providing a process controller, suitably a .. process controller (PC), desirably a programmable logic controller (PLC).
This may involve generating a process operation model based on inputs of sensed conditions, in which the inputs of sensed conditions comprise at the respective items of information (11), (13), (14), Date Recue/Date Received 2022-03-14 BASF SE

and (15) as defined herein. The process controller (PC), suitably programmable logic controller (PLC), can issue commands based on the process operation model, and using these commands to control the respective parameters which may be regarded as may be regarded as controllable parameters.
One desirable embodiment concerns a method for separating solids from a tailings slurry (TS), which tailings slurry (TS) has a solids content of from 25 to 70% by weight and comprises sand particles and fines particles with a sand to fines ratio (SFR) of from 0.5:1 to 5:1, wherein the fines particles comprise clay, a. forming at least one first mass flow (MS1) of the tailings slurry (TS) entering at least one containment, which the at least one containment comprises at least one first mixing region (MR1), b. subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG1) in the at least one first mixing region (MR1), wherein fluidity measurements (FM1) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MR1) to exiting the at least one first mixing region (MR1), c. optionally flowing the tailings slurry (TS) from the at least one first mixing region (MR1) to at least one second mixing region (MR2) as at least one second mass flow (M52), said at least one second mixing region (MR2) having at least one agitation means (AG2), d. optionally subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG2) in the at least one second mixing region (MR2), wherein fluidity measurements (FM2) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), e. adding a clay de-coagulant reagent (DGR) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one first mass flow (MS1) and the at least one first mixing region (MR1), said at least one first mixing region (MR1) having at least one agitation means (AG1), f. adding a flocculent (F) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one at least one first mass flow (MS1), the first mixing region (MR1), the at least one second mass flow (M52) and the at least one second mixing region (MR2), Date Recue/Date Received 2022-03-14 BASF SE

g. flowing the tailings slurry (TS) from either or both (i) the at least one first mixing region (MRI) and/or (ii) the at least one second mixing region (MR2) as at least one conditioned tailings stream (CTR), h. separating the at least one conditioned tailings stream (CTR) into a solids rich phase and a solids depleted liquor, wherein the method comprises (A) at least one item of information (11);
(B) optionally at least one item of information (13);
(C) optionally at least one item of information (14); and (D) at least one item of information (15), wherein A. the at least one item of information (11) is associated with the at least one first mass flow (MSI) and is directly or indirectly selected from the group consisting of the sand to fines ratio (SFR); the solids content; specific gravity; clay content; and the flow rate, B. the at least one item of information (13) is associated with the fluidity measurements (FM1) showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MRI) to exiting the at least one first mixing region (MRI), C. the at least one item of information (14) is associated with fluidity measurements (FM2) showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), D. the at least one item of information (15) is associated with (15a) the at least one conditioned tailings stream (CTR); and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated therefrom, wherein (15a) is associated with changes to the structure of the conditioned tailings stream (CTR) and (I5b) is associated with changes in at least one of the group selected from solids/liquid separation rate;
volume of released liquid; turbidity of released liquid; and moisture content of separated solids, Characterised in that, either (I) the method comprises the at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) mixing in the at least one first mixing region (MRI);
and the at least one second mixing region (MR2) and includes subjecting the tailings slurry (TS) to mixing in the at least one second mixing region (MR2), wherein Date Recue/Date Received 2022-03-14 BASF SE

the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii), (iii) and (iv):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), (iv) the initial rate of mixing provided by the at least one agitation means (AG2), and (v) reset at least one of (i) to (iv) according to said predefined conditions, in which at least one of (IA) and/or (1B) are employed, (IA) the item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AGI), and/or (1B) the combination of items of information (14) and (15) is used to adjust the rate of mixing provided by the at least one agitation means (AG2);
and the item of information (15) is used to adjust the dose of either the clay de-coagulant reagent (DGR) and/or the flocculent (F), or (II) the method employs as mixing region(s) solely at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) to mixing in the at least one first mixing region (MRI), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii) and (iii):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG 1), and (v) reset at least one of (i) to (iii) according to said predefined conditions;
the combination of items of information (15) and (13) is used to adjust the rate of mixing provided by the at least one agitation means (AGI);

Date Recue/Date Received 2022-03-14 BASF SE

and item of information (15) is used to adjust the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F), wherein the method further comprises providing a process controller, suitably a programmable logic controller, generating a process operation model based on inputs of sensed conditions, wherein the inputs of sensed conditions comprise the items of information (11), (13), (14) and (15) using the process controller, suitably programmable logic controller, issuing commands based on the process operation model, using said commands to control at least one controllable parameter, said at least one controllable parameter preferably selected from at least one of the group consisting of the dose of clay de-coagulant reagent (DGR) added to the tailings slurry (TS), the point of addition of the clay de-coagulant reagent (DGR) added to the tailings slurry, the dose of flocculent (F) added to the tailings slurry (TS), the point of addition of the flocculent (F) added to the tailings slurry (TS), the degree of agitation associated with the at least one agitation means (AG1), the degree of agitation associated with the at least one agitation means (AG2), the sand to fines ratio (SFR) of the at least one first mass flow (MS1), the solids content of the at least one first mass flow (MS1) and the flow rate of the at least one first mass flow (MS1).
This preferred embodiment comprising a process controller may be used in combination with any of the other embodiments described in the specification. As one example the at least one item of information (12) concerning the at least one second mass flow (M52) may be used as described above in connection with the first aspect of the invention.
Preferably, the process controller, suitably programmable logic controller, may issue commands based on the process operation model, using said commands to control the controllable parameters based on the respective items of information as given herein. In respect of the first aspect of the invention this would be (i) the initial dose of the clay decoagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AG1), (iv) the initial rate of mixing provided by the at least one agitation means (AG2), (v) resetting at least one of (i) to (iv), (vi) adjusting the rate of mixing provided by the at least one agitation means (AG1), (vii) adjusting the rate of mixing provided by the at least one agitation means (AG2), (viii) adjusting the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F). In respect of the second aspect of the invention this would be (i) the initial dose of the clay decoagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at Date Recue/Date Received 2022-03-14 BASF SE

least one agitation means (AG1), (v) resetting at least one of (i) to (iii), (vi) adjusting the rate of mixing provided by the at least one agitation means (AG1), (viii) adjusting the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F). More preferably in respect of both the first aspect and second aspect of the invention, the process controller, .. suitably programmable logic controller, may issue commands based on the process using said commands to set or reset the initial points of addition for the clay decoagulant reagent (DGR) and the initial point of addition of flocculent (F) and furthermore control any variation of the respective points of addition.
The clay decoagulant reagent (DGR) may be any chemical additive that changes clay from a coagulated state to substantially uncoagulated form in which the clay platelets tend to be substantially separated. It is believed that the clay decoagulant reagent (DGR) serves to reduce the electrostatic attractive forces between the coagulated clay particles to render the particles fully and/or partially separated.
By clay being in a coagulated state, we mean that clay platelets are linked to each other, typically by electrostatic forces on the platelet faces and/or edges. Clays may exist in a number of coagulated states and typically these include arrangements where the platelets are linked in a face-to-face structure; a mixture of face-to-face and edge to face structures; a mixture of edge to face and edge-to-edge structures; and edge-to-edge structures. When the clay is in a substantially un-coagulated form the clay platelets tend to be substantially separated. Aqueous slurries tend to exhibit highest viscosity when the clay platelets contain edge to face structures, for instance mixtures of edge to face and edge-to-edge structures and especially mixtures of edge to face and edge-to-edge structures. This is illustrated in Figure 3.
Those aqueous slurries which contain clay in a coagulated form, particularly where the coagulated structure induces high viscosities, for instance as understood often to be the case when the slurries are oil sands MFT slurries or oil sands FFT slurries, tend to be particularly difficult to dewater. Without being limited to theory, the inventors believe that the effectiveness of the inventive method may be as a result of the clay decoagulant reagent (DGR) breaking down the electrostatic forces between coagulated clay platelets so as to allow the polymer chains of the flocculent (F) to attach to a greater proportion of the suspended solids without interference from the coagulated clay. This allows for the improved release of water which would have been otherwise trapped inside of the coagulated clay structures. The inventors believe that the de-coagulant reagent (DGR) is acting on the coagulated clay particles by breaking down or diminishing electrostatic attractive forces Date Recue/Date Received 2022-03-14 BASF SE

between them and hence transferring the clay particles into a form of fully and/or partially separated particles (as depicted in Figure 3).
The clay decoagulant reagent (DGR) may be organic or inorganic. Suitable materials may be polymeric.
Particularly suitable examples of organic polymeric clay decoagulant reagents (DGR) may include at least one of the categories of compounds known as ionic polymeric decoagulants.
Ionic polymeric de-coagulant as the DGR suitably may include water-soluble polymers exhibiting a weight average molar mass of below 1.5 million g/mol, for instance below 1 million g/mol, such as below 500,000 g/mol or below 100,000 g/mol. In general, the at least one ionic polymeric de-coagulant would tend to have a lower weight average molar mass, typically up to 50,000 g/mol. Desirably, the weight average molar mass of the at least one ionic polymeric de-coagulant may tend to be in the range of from 500 to 50,000 g/mol, for instance from 1000 to 40,000 g/mol, such as 2000 to 30,000 g/mol, or 3000 to 20,000 g/mol.
The at least one ionic polymeric de-coagulant may typically be a combination of different ionic polymeric de-coagulants each having a weight average molar mass of below 1 million g/mol or any of the more precise ranges of molar mass referred to herein.
The at least one ionic polymeric de-coagulant as DGR may be cationic, anionic, amphoteric or zwitterionic. In the context of the present invention cationic means that the ionic polymeric de-coagulant carries positive charges, anionic means that the ionic polymeric de-coagulant carries negative charges and amphoteric means that the ionic polymeric de-coagulant carries both positive and negative charges. By zwitterionic we mean that the ionic polymeric de-coagulant contains positive and negative charges carried on the same repeating monomeric units. Preferably, however, the at least one ionic polymeric de-coagulant is anionic.
Typical ionic polymeric de-coagulants that may be used as the DGR include poly(naphthalene sulphonate), prepared for instance by reacting formaldehyde and naphthalene sulphonate. Other possible ionic polymeric de-coagulants include polymers based on melamine sulphonates and acetone/formaldehyde sulphonates. Generally, these materials may be prepared by a condensation reaction. Suitable polymers of this category may be those described in US 4725665 and US 3277162 which disclose the synthesis of naphthalene sulphonic acid/formaldehyde condensates starting from naphthalene, sulphuric acid and formaldehyde. In the synthesis naphthalene is initially reacted with concentrated Date Recue/Date Received 2022-03-14 BASF SE

sulphuric acid to form naphthalene sulphonic acid which is reacted with formaldehyde in a polycondensation reaction and then finally neutralisation utilising a suitable base, such as sodium hydroxide or calcium hydroxide. The use for improving the flowability of inorganic binders like cement and as fluid (water) loss additives in cements for oil wells, respectively, is described. Suitable polymers based on melamine sulphonates are described in US
6555683. This document describes the preparation of the polycondensate based on melamine sulphonates and their use to liquefy inorganic binder suspensions.
These may be synthesised by reacting melamine with formaldehyde and a sulphite at alkaline pH followed by a polycondensation reaction at acidic pH and finally neutralising the polymer with sodium hydroxide. Suitable polymers based on acetone, formaldehyde sulphonate condensates are described in US 4818288 and US 4657593 which describe such condensates for use as dispersants for inorganic binders and US 4657593 describes the use of these compounds as dispersion agents for kaolin and clay suspensions. The condensates are produced by reacting acetone and sodium sulphite with formaldehyde in a polycondensation reaction to give directly the desired polycondensate.
Preferably, however, the DGR includes a type of ionic polymeric de-coagulant which is a water-soluble polymer derived from ethylenically unsaturated monomers. One preferred category of water-soluble polymers includes those polymers prepared from one or more ethylenically unsaturated acid monomers or salts thereof. These polymers may be homopolymers of the one or more ethylenically unsaturated acid monomers (or salts thereof) or they may be copolymers of said one or more ethylenically unsaturated acid monomers (or salts thereof) and one or more ethylenically unsaturated non-ionic monomers.
Typically, these ethylenically unsaturated non-ionic monomers may be selected from the group consisting of acrylamide, methacrylamide, hydroxy alkyl acrylate, vinyl acetate, vinyl alcohol, vinyl alkyl ether, allyl alkyl ether, styrene and C1_8 alkyl acrylates.
Suitable hydroxy alkyl acrylates as non-ionic comonomers may include any of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate; and suitable hydroxyalkyl methacrylates include hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl methacrylate.
Suitable C1_8 alkyl acrylates as non-ionic comonomers may include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, ethylhexyl acrylate, n-octyl acrylate, or cyclohexyl acrylate.
Suitable allyl alkyl ethers as non-ionic monomers may include allyl methyl ether, allyl ethyl ether, allyl n-propyl ether or allyl isopropyl ether.

Date Recue/Date Received 2022-03-14 BASF SE

The ethylenically unsaturated acid monomers for preparing the aforesaid homopolymers or copolymers as the ionic polymeric de-coagulant, may be any suitable ethylenically unsaturated monomer bearing an acid group. Suitable acid groups may include carboxylic acids, sulphonic acids, sulphuric acids, phosphoric acids or phosphonic acids.
By referring to the specific ethylenically unsaturated acid monomers we also include the corresponding salts thereof by this definition. We also include the corresponding anhydride of an acid group in the definition of ethylenically unsaturated acid monomers. Suitable monomers in this category include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, ethacrylic acid, crotonic acid, mono esters of ethylenically unsaturated dicarboxylic acids, such as mono methyl maleate, mono methyl fumarate, mono ethyl maleate, mono n butyl maleate, and mono n butyl fumarate, styrene carboxylic acids, maleic anhydride, itaconic anhydride, 2-acrylamido-2-methylpropylene acid, vinylsulfonic acid, allyl sulphonic acid, vinylphosphonic acid, 2-hydroxy ethyl methacrylate phosphate.
Preferred ionic polymeric de-coagulants for use as the DGR are selected from the group consisting of a homopolymer of acrylic acid (or salts thereof) and a copolymer of a monomer mixture consisting of acrylic acid (or salts thereof) and acrylamide. Suitable ionic polymeric de-coagulants of this category may include polymers in the Dispex or Sokalan product ranges supplied by BASF.
Another particularly suitable category of ionic polymeric de-coagulants as the DGR include anionic polymers derived from ethylenically unsaturated monomers and said polymer comprising repeating monomeric units carrying pendant polyalkyleneoxy groups.
Suitable ionic polymeric de-coagulants may be prepared in accordance with US 6777517, US
2012/0035301 or CA 2521173.
Preferred ionic polymeric de-coagulants as the DGR include polymers comprising repeating units derived from monomers, (i) an ethylenically unsaturated anionic or non-ionic monomer containing a polymerisable moiety (M) and having the structure M ¨ R2¨ X ¨ (- CH2¨ CHR5 ¨ 0 -), ( ¨ CH2 ¨ CH2¨ 0 ¨)m CH2¨ CHR3 ¨ 0 -), ¨ R4 (I) in which X is 0 or NH, Date Recue/Date Received 2022-03-14 BASF SE

R2 is independently a single bond or a divalent linking group selected from the group consisting of ¨(CH2¨)p- and ¨0¨(CH2¨)s where p is a number from 1 to 6 and s is a number from 1 to 6, R3 and R5 are each independently a hydrogen or hydrocarbyl radical having 1-4 carbon atoms, R4 is independently a hydrogen or a hydrocarbyl radical having 1-4 carbon atoms or a moiety having the structure ¨ ( ¨ CH 2¨ CH2¨ 0 ¨)k-Y
k is a number from 1 to 20 I is a number from 0 to 250;
m is a number from 1 to 300, n is a number from 0 to 250;
Y is hydrogen or a hydrocarbyl radical having 1-4 carbon atoms, and (ii) at least one ethylenically unsaturated monomer carrying at least one anionic functional group different from component (i);
and (iii) optionally at least one ethylenically unsaturated non-ionic monomer, different from component (i).
In the present invention, M maybe any suitable polymerisable ethylenically unsaturated moiety. Preferably, M is selected from a vinyl moiety, an ethylenically unsaturated carboxylic moiety, an ethylenically unsaturated amide moiety, an allyl moiety or isoprenyl moiety.
More preferably, M is selected from the group consisting of:
H2C=C(R1)¨ (II);
H2C=C(R1)¨CH2¨ (III);
H2C=C(R1)¨00¨ (IV);
HOOC¨HC=C(R1)¨00¨ (V); and ¨0C¨HC=C(R1)¨00¨(VI), in which R1 is hydrogen or methyl.
It will be apparent to the person skilled in the art in the field of polyalkylene oxides that the numbers in regard to I, m and n mentioned are mean values of distributions.

Date Recue/Date Received 2022-03-14 BASF SE

It will be apparent to the person skilled in the art in the field of polyalkylene oxides that the orientation of the respective hydrocarbyl radicals R3 and R5 may depend on the conditions in the alkoxylation, for example on the catalyst selected for the alkoxylation in the polymerisation reaction of the copolymer of the present invention. The alkyleneoxy groups can thus be incorporated into the monomer (i) in the orientation ¨(¨CH2¨CH(R5)-0-)1¨ or else the inverse orientation ¨(¨CH(R5)-CH2-0-)1¨ and the orientation ¨(¨CH2¨CH(R3)-0-)n¨
or else the inverse orientation ¨(¨CH(R3)-CH2-0-),¨. The representation in formula (I) shall therefore not be regarded as being restricted to a particular orientation of the R3 or R5 groups.
Monomer (i) of general formula (I) suitably contains the following preferred features:
Preferably integers I and n are each zero.
Integer m is preferably from 5 to 250, more preferably from 10 to 200, even more preferably from 45 to 175 and most preferably from 45 to 175.
Preferably, R1 is hydrogen.
If R2 is not a single bond then preferably integer s is 4; or integer p is 1 or 2.
Preferably, M is a vinyl, or maleic mono ester group.
One suitable group of monomers as monomer (i) of the general formula (I) is vinyloxybutyl polyethylene glycol, in which the polyethylene glycol moiety contains from 45 to 175 repeating ethylenoxide units, preferably containing from 75 to 150 repeating ethylenoxide units, more preferably containing from 100 to 150 repeating ethylenoxide units, particularly from 110 to 140 repeating ethylenoxide units, more particularly from 120 to 140 repeating ethylenoxide units. An especially preferred monomer (i) of general formula (I)is the adduct of 129 moles of ethylene oxide with 4-hydroxy butyl mono vinyl ether.
A further suitable group of monomers as monomer unit (i) of general formula (I) is based on the reaction of 4-hydroxy butyl vinyl ether which has been ethoxylated, then butoxylated and then ethoxylated. This group of monomers may be described as vinyloxybutyl polyethylene glycol polybutadiene glycol polyethylene glycol or may be defined as vinyloxybutyloxy (E0)a (B0)b (E0)c, in which EO represents repeating ethylenoxide units, BO
represents repeating butylene units and each of a, b, c independently represents numbers. Suitably, a may be from 5 to 75, b may be from 1 to 30 and c may be from 0 to 20. Preferably, a may be from 10 Date Recue/Date Received 2022-03-14 BASF SE

to 50, b may be from 2 to 20 and c may be from 0 to 20. More preferably, a may be from 15 to 40, b may be from 5 to 20 and c may be from 0 to 10. More preferably still, a may be from 24 to 25, b may be from 10 to 20 and c may be from 0 to 5. One particularly suitable monomer is where a is from 24-25, b is from 15-17 and c is from 3-4.
Another suitable monomer (i) of the general formula (I) is poly (PO block-EO) maleamide which may be prepared by the reaction of Jeffamine Monoamines (M series) (available from Huntsman) with maleic anhydride in the ratio of 1:1 to give the mono amide. By PO
block-EO it is understood that this means a block of propylene oxide units and a block of ethylene oxide units. The at least one ethylenically unsaturated monomers that carries an anionic functional group of category (ii) may be any suitable anionic ethylenically unsaturated monomer. Suitable anionic functional groups may include carboxylic acids, sulphonic acids, sulphuric acids, phosphoric acids or phosphonic acids. By referring to the specific ethylenically unsaturated anionic monomers we also include the corresponding salts thereof by this definition. We also include the corresponding anhydride of an acid group in the definition of ethylenically unsaturated anionic monomers. Suitable monomers in this category include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, ethacrylic acid, crotonic acid, mono esters of ethylenically unsaturated dicarboxylic acids, such as mono methyl maleate, mono methyl fumarate, mono ethyl maleate, mono n butyl maleate, and mono n butyl fumarate, styrene carboxylic acids, maleic anhydride, itaconic anhydride, 2-acrylamido-2-methylpropylene acid, vinylsulfonic acid, allyl sulphonic acid, vinylphosphonic acid, 2-hydroxy ethyl methacrylate phosphate.
A still further type of suitable monomers (i) of general formula (I) are based on methacrylic esters and acrylic esters. Examples of these are mono methacrylate adduct of ethylene oxide units. Typical examples of these may be found in US 5707445, particularly in the examples in column 7 by reference to monomers A-1 (mono methacrylate of adduct of methanol with ethylene oxide (EO) units (average number of EO units of 115));
A-2 (mono methacrylate adduct of methanol with EO repeating units (average number 220));
A-3 (mono methacrylate adduct of methanol with repeating EO units (average number 280));
A-5 (block adduct of acrylic acid with 10 propylene oxide (PO) units and EO units (average number 135)); A-6 (block adduct of acrylic acid with EO and PO (average number of EO
molecules 135 and average number of PO molecules added 5)); and A-8 (mono methacrylate of adduct of methanol with EO (average number of EO molecules 100)).Preferably monomer component of category (ii) is either acrylic acid (or salts thereof), maleic anhydride or maleic acid (or salts thereof).
Date Recue/Date Received 2022-03-14 BASF SE

Suitable ethylenically unsaturated non-ionic monomers of category (iii) may be any suitable non-ionic ethylenically unsaturated monomer that is different from the monomers of category (i) and be copolymerisable with the monomers of categories (i) and (ii).
Desirably, these monomers may be selected from the group consisting of acrylamide, methacrylamide, hydroxy alkyl acrylate, hydroxy alkyl methyl acrylate, vinyl acetate, vinyl alcohol, allyl alkyl ether, styrene, and alkyl acrylates.
Suitable hydroxy alkyl acrylates as non-ionic comonomers may include any of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate; and suitable hydroxyalkyl methacrylates include hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl methacrylate.
Suitable C1_8 alkyl acrylates as non-ionic comonomers may include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, ethylhexyl acrylate, n-octyl acrylate, or cyclohexyl acrylate.
Suitable allyl alkyl ethers as non-ionic monomers may include allyl methyl ether, allyl ethyl ether, allyl n-propyl ether or allyl isopropyl ether.
The ranges of the respective repeating units are suitably as follows:
Monomer (i) is preferably from 1 to 50 moles %; monomer (ii) is preferably from 50 to 99 mole %; and monomer (iii) is preferably from 0 to 33 mole %. More preferably, monomer (i) is from 5 to 40 mole %; monomer (ii) from 60 to 95 mole %; and monomer (iii) from 0 to 25 mole %. Even more preferably, monomer (i) is from 10 to 30 mole %; monomer (ii) from 70 to 90 mole %; and monomer (iii) is preferably 0%.
The weight average molar mass of the ionic polymeric de-coagulant as DGR
formed from monomers (i), (ii) and optionally (iii) is preferably from 1000 to 100,000 g/mole, more preferably from 5000 to 70,000 g/mole, even more preferably from 10,000 to 65,000 g/mole, more preferably still from 20,000 to 60,000 g/mole, especially from 25,000 to 60,000 g/mole and most preferably from 30,000 to 60,000 g/mole.
The weight average molar mass may be determined by gel permeation chromatography (GPC) with the following method: column combination: Shodex OH-Pak SB 804 HQ
and OH-Pak SB 802.5 HQ from Showa Denko, Japan; eluent: 80 vol % aqueous solution of HCO2NH4 (0.05 mo1/1) and 20 vol% Me0H; injection volume 100 pl; flow rate 0.5 ml/min.
The weight average molar mass may be calibrated using standards from PSS
Polymer Standard Service, Germany. For the UV detector, poly(styrene-sulfonate) standards may be Date Recue/Date Received 2022-03-14 BASF SE

used, and poly(ethylene oxide) standards for the RI detector. The weight average molar mass may then be determined using the results of the RI detector.
The preparation of suitable polymeric products containing monomers (i) and (ii) and optionally containing component (iii) is described in US 6777517, US
2012/0035301 or CA
2521173.
One particularly suitable group of ionic polymeric de-coagulant as DGR is formed from the terpolymer of vinyloxybutyl polyethylene glycol (i); acrylic acid as a monomer (ii); and maleic anhydride as a further monomer (ii). The polyethylene glycol moiety preferably contains from 45 to 175 repeating ethylenoxide units, preferably containing from 75 to 150 repeating ethylenoxide units, more preferably containing from 100 to 150 repeating ethylenoxide units, particularly from 110 to 140 repeating ethylenoxide units, more particularly from 120 to 140 repeating ethylenoxide units. Particularly preferably the monomer (i) is the adduct of 129 moles of ethylene oxide with 4-hydroxybutyl monovinyl ether. The molar ratio of the aforesaid three monomers is preferably 0.8-1.2/4/0.4-0.8 and suitably has a weight average molar mass of from 45,000 to 60,000 g/mole. The preparation of a particularly suitable polymer for use as the ionic polymeric de-coagulant as DGR is described in US
2012/0035301 on page 4 under heading Polymer 1.
Another suitable group of ionic polymeric de-coagulant as DGR is formed from the terpolymer of vinyloxy butyl polyethylene glycol polybutylene glycol polyethylene glycol (as described above) (i): acrylic acid as a monomer (ii); and maleic anhydride as a further monomer (ii). The monomer (i) vinyloxybutyloxy (E0)a (B0)b (E0)c, in which EO
and BO
have each been defined above and in which suitably a may be from 5 to 75, b may be from 1 to 30 and c may be from 0 to 20. Preferably, a may be from 10 to 50, b may be from 2 to 20 and c may be from 0 to 20. More preferably, a may be from 15 to 40, b may be from 5 to 20 and c may be from 0 to 10. More preferably still, a may be from 24 to 25, b may be from 10 to 20 and c may be from 0 to 5. One particularly suitable monomer is where a is from 24-25, b is from 15-17 and c is from 3-4. The molar ratio of the aforesaid three monomers is suitably 2-5/4/0.8-1.2 and the weight average molar mass of from 15,000 to 45,000 g/mole.
Other suitable polymers as ionic polymeric de-coagulants as DGR are described in US
2012/0035301, particularly the examples.
Further suitable polymers as ionic polymeric de-coagulants as DGR include copolymers of methacrylic or acrylic esters of formula (I) with ethylenically unsaturated carboxylic acids or Date Recue/Date Received 2022-03-14 BASF SE

corresponding salts such as acrylic acid (or salts thereof), methacrylic acid (or salts thereof) or maleic acid (or salts thereof or the anhydride). Suitable methacrylic esters of formula (I) would include monomers A-1, A-2, A-3, A-5, A-6 and A-8 given in US 5707445 (described above). Suitable examples of such suitable polymers for this application are given in US
5707445 for instance the Preparative Example 3 and Preparative Example 5.
Examples of other suitable polymers are also given in EP 1142847 A2 and particularly in Reference Example 3 and Reference Example 4.
Yet further suitable polymers as ionic polymeric de-coagulants as DGR include copolymers of polyethylene glycol mono methyl ether methacrylate copolymers with ethylene glycol methacrylate phosphate optionally with methacrylic acid. Desirable examples of these polymers are given in US 2008/146700 and with specific reference to Table 1 and in particular Polymer Numbers 5-8, 14 and 15.
By water-soluble in respect of the ionic polymeric de-coagulant as DGR, we mean that the polymers exhibit a solubility in water of at least 5 g per 100 ml of water at 25 C.
The ionic polymeric de-coagulant may suitably have a charge density of from 0.2 to 10 meq/g (milliequivalents per gram), preferably from 0.3 to 8 meq/g, more preferably from 0.5 to 5 meq/g and most preferably from 0.8 to 3 meq/g.
The at least one ionic polymeric de-coagulant as DGR may be used in conjunction with other additives. This may be by the inclusion of one or more additives together with the at least one ionic polymeric de-coagulant, for instance as at least one compound present as a mixture together with the at least one ionic polymeric de-coagulant. Examples of typical additives that may be used in conjunction with the at least one ionic polymeric de-coagulant include polyethylene glycol (PEG), polyethylene glycol derivatives (such as monofunctional polyethylene glycol monoalkyl ethers) or polyvinyl alcohol. Suitable polyethylene glycols may have weight average molar masses of up to 50,000 g/mol but are usually within the range of from 50 g/mol to 30,000 g/mol, typically in the range of from 100 to 20,000 g/mol, for instance from 200 to 20,000 g/mol or 200 to 10,000 g/mol, such as from 200 to 5000 g/mol, typically from 200 to 1000 g/mol or from 300 to 500 g/mol. The polyethylene glycols may have any particular geometry, for instance linear, branched, star, comb structures. Suitable polyethylene glycols are commercially available and may be available, for instance from Dow Chemical under the tradename Carbowax , or from BASF under the tradename PlurioleE
or from Clariant under the name PolyglykoleM.

Date Recue/Date Received 2022-03-14 BASF SE

The at least one ionic polymeric de-coagulant when used as DDR may be a mixture of different ionic polymeric de-coagulants. Such a mixture may include a first mixture component based on one or more of any of the aforementioned ionic, especially anionic, polymers derived from ethylenically unsaturated monomers and being a polymer comprising repeating monomeric units carrying pendant polyalkyleneoxy groups and a second mixture component being one or more different ionic polymeric de-coagulants as described herein.
Such different ionic polymeric de-coagulant as second mixture component may be a homopolymer or copolymer of acrylic acid (or salts thereof), for instance any of those polymer types analogous to the Dispex or Sokalan product ranges. Preferably the mixture of different ionic polymeric de-coagulants comprises as first mixture component being a polymer in the aforementioned category formed from monomers (i), (ii), and optionally (iii) and the second mixture component being an anionic copolymer or anionic homopolymer, particularly of the polymer types analogous to Dispex or Sokalan product ranges.
Typical doses of the polymeric ionic de-coagulant as DGR may range from 0.1 to 1000 g polymer per tonne of solids content of the aqueous slurry, suitably from 1 to 800 g per tonne, such as 10 to 600 g per tonne, for instance 20 to 500 g per tonne, desirably from 50 to 400 g per tonne, for instance from 75 to 350 g per tonne, suitably from 100 to 300 g per tonne, for instance from 150 to 250 g per tonne. The exact doses of the polymeric ionic decoagulant as DGR may depend on the particular aqueous slurry, including the particular particulate mineral material of the slurry and the solids content of the slurry.
Suitable examples of clay decoagulant reagents (DGR) include inorganic materials and in particular aluminosilicate nano particulate material. In one desirable embodiment the aluminosilicate nano particulate material has a molar ratio of aluminium to silicon from 0.7:1 to 3:1. Suitably, the molar ratio of aluminium to silicon may be from 0.8:1 to 2.9:1 or from 0.8:1 to 2.8:1. Desirably the aluminosilicate nanoparticulate material has a molar ratio of aluminium to silicon of from 0.8:1 to 2.5:1. Preferably the molar ratio of aluminium to silicon should be from 0.9:1 to 2.2:1 or 0.9:1 to 2.1:1 or 0.9:1 to 2:1, for instance from 1:1 to 2:1.
The aluminosilicate nanoparticulate material as DGR may be prepared by combining an aqueous aluminate solution with an aqueous silicate solution. Typically, the aqueous aluminate can be an aqueous aluminate salt, for instance an alkali metal aluminate salt such as potassium aluminate, sodium aluminate or lithium aluminate. The aqueous silicate solution can be an aqueous silicate salt, for instance an alkali metal silicate salt such as potassium silicate, sodium silicate or lithium silicate. Suitably, the aqueous aluminate Date Recue/Date Received 2022-03-14 BASF SE

solution may be at a concentration of from 0.2% to 3% (wt./wt. as A1203).
Preferably, the concentration should be from 0.5% to 2%, more preferably from 0.75% to 1.5%.
Suitably, the aqueous silicate solution may be at a concentration of from 0.2% to 3%
(wt./wt. as 5i02).
Preferably, the concentration should be from 0.5% to 2%, more preferably from 0.75% to 1.5%.
The aqueous aluminate solution and the aqueous silicate solution desirably should be combined under continuous mixing conditions. This can be done by adding one of the aqueous solutions to the other aqueous solution which is in a vessel with constant stirring or agitation. Alternatively, the two aqueous solutions may be combined as to flowing streams followed by mixing. In this case the mixing may be achieved by employing an in-line static mixer or baffles or by employing in-line active mixing, for instance employing a CSTR
(continuous stirred tank reactor).
The ratio of respective volumes and/or respective concentrations of aqueous aluminate solution and aqueous silicate solution should be chosen to be sufficient to provide a molar ratio of from 0.7:1 to 3:1 aluminium to silicon or any of the other more specific ratios within this range identified above.
The aqueous aluminate solution and the aqueous silicate solution desirably should be combined at an ambient temperature, for instance from 10 C to 30 C, preferably 15 C to C, suitably, from 17 C or 18 C to 22 C or 23 C. The reaction time may tend to vary according to the temperature at which the reaction is taking place. Typically, there is an inverse relationship between reaction time and temperature in that at higher temperatures 25 the reaction tends to be faster.
Suitably, the aluminosilicate nanoparticulate material as DGR consists predominantly of particles of size below 50 nm. By predominantly we mean that greater than 50%
by weight of the aluminosilicate nanoparticulate material. Typically, the aluminosilicate nanoparticulate material comprises from 55% to 100% by weight of particles of size below 50 nm. Often, the aluminosilicate nanoparticulate material comprises from 60% to 95%, desirably from 65% to 90%, or from 70% to 85% by weight of particles of size below 50 nm. Desirably, greater than 50% by weight of the aluminosilicate nanoparticulate material comprises particles of size below 30 nm, preferably below 20 nm.
The aluminosilicate nanoparticulate material as DGR may comprise cage like structures that form a network comprising aluminium, silicon and oxygen atoms. The inventors believe that Date Recue/Date Received 2022-03-14 BASF SE

the aluminosilicate nanoparticulate material may comprise zeolite such as Zeolite A or Faujasite or Sodalite or mixtures thereof. In general, there is expected to be a predominance of Sodalite aluminosilicate structures. By this we mean that it is likely that the aluminosilicate nanoparticulate material is made up from greater than 50% by weight of Sodalite. This is believed to be the case in view of the relatively higher ratio of aluminium to silicon. Suitably, the aluminosilicate nanoparticulate material comprises from 55 to 100% by weight of Sodalite, desirably from 60 to 100% by weight of Sodalite, typically from 70%
to 95% by weight of Sodalite, usually from 75% to 90% by weight of Sodalite. Sodalite is formed from 13 cages which are linked directly through square faces. Sodalite is not strictly considered to be a zeolite. Zeolite A is formed from 13 cages that are linked through square faces but with a D4R spacer. Faujasite is also formed from 13 cages but linked through hexagonal faces but with a D6R spacer.
Typical doses of the aluminosilicate nanoparticulate material as DGR lie in the range of from

10 to 2000 g aluminosilicate nanoparticulate material (based on solids content) per tonne of solids content of the aqueous slurry. Desirably, this may be from 20 to 1500 g per tonne, suitably from 30 or 40 or 50 to 1000 g per ton, often from 75 to 750 g per tonne, frequently from 90 to 500 g per tonne, usually from 100 to 400 g per tonne. The exact doses of the aluminosilicate number particulate material as DGR may depend on the particular aqueous slurry, including the particular particulate mineral material of the slurry and the solids content of the slurry.
The flocculent (F) may be a polymer having an intrinsic viscosity of at least 5 dl/g (measured at 25 C in 1 M NaCI). The polymer may be non-ionic, anionic, amphoteric or cationic.
Typically, this may be formed from ethylenically unsaturated monomers. In the case of a non-ionic polymeric flocculent the polymer may be derived from at least one non-ionic ethylenically unsaturated monomer. In the case of an anionic polymeric flocculent, the polymer may be derived from at least one anionic ethylenically unsaturated monomer, optionally including at least one ethylenically unsaturated non-ionic monomer.
When the polymeric flocculent is cationic, it may be derived from one or more ethylenically unsaturated cationic monomers, optionally in combination with an ethylenically unsaturated non-ionic monomer. Where the polymeric flocculent is amphoteric, this may be derived from ethylenically unsaturated anionic monomers and ethylenically unsaturated cationic monomers, optionally in combination with ethylenically unsaturated non-ionic monomers.
Preferably, the flocculent (F) is a polymer formed from repeating units derived from at least one ethylenically unsaturated monomer bearing an anionic group and optionally at least one ethylenically unsaturated non-ionic monomer.

Date Recue/Date Received 2022-03-14 BASF SE

Preferably still, the flocculent (F) is a water-soluble polymer derived from ethylenically unsaturated monomers selected from the group consisting of homopolymers of one or more ethylenically unsaturated acid monomers (or salts thereof); and copolymers formed from a monomer mixture comprising of (A) one or more ethylenically unsaturated acid monomers (or salts thereof), (B) one or more ethylenically unsaturated non-ionic monomers selected from the group consisting of acrylamide, methacrylamide, hydroxy alkyl acrylate, vinyl acetate, vinyl alcohol, allyl alkyl ether, styrene and C18 alkyl acrylates (C) one or more other ethylenically unsaturated monomers different from (A) and (B). Ethylenically unsaturated monomers in category (C) may include other ethylenically unsaturated non-ionic monomers not specified in category (B) or alternatively it may be ethylenically unsaturated monomers bearing a cationic functional group.
Suitable hydroxy alkyl acrylates as non-ionic comonomers may include any of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate; and suitable hydroxyalkyl methacrylates include hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl methacrylate. Suitable C1_8 alkyl acrylates as non-ionic comonomers may include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, ethylhexyl acrylate, n-octyl acrylate, or cyclohexyl acrylate.
The at least one ethylenically unsaturated acid monomers of category (A) may be any suitable anionic ethylenically unsaturated monomer. Suitable acid groups may include carboxylic acids, sulphonic acids, sulphuric acids, phosphoric acids or phosphonic acids. By referring to the specific ethylenically unsaturated acid monomers we also include the corresponding salts thereof by this definition. We also include the corresponding anhydride of an acid group in the definition of ethylenically unsaturated acid monomers.
Suitable monomers in this category include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, ethacrylic acid, crotonic acid, mono esters of ethylenically unsaturated dicarboxylic acids, such as mono methyl maleate, mono methyl fumarate, mono ethyl maleate, mono n-butyl maleate, and mono n-butyl fumarate, styrene carboxylic acids, maleic anhydride, itaconic anhydride, 2-acrylamido-2-methylpropylene acid, vinylsulfonic acid, allyl sulphonic acid, vinylphosphonic acid, 2-hydroxy ethyl methacrylate phosphate.
Flocculent (F) may be a polymer comprising components (A), (B) and contains component (C), desirably the other ethylenically unsaturated monomers (C) may be selected from one or more cationic monomers, provided that the overall anionic equivalent content is greater Date Recue/Date Received 2022-03-14 BASF SE

than the overall cationic equivalent content. Suitably, the one or more cationic monomers are included in the monomer mixture in an amount of up to 10 mol % total cationic monomer based on the total molar content of monomers in the monomer mixture.
More preferably, the flocculent (F) is a copolymer of acrylamide with (meth)acrylic acid (or salt thereof) or a homopolymer of (meth)acrylic acid (or salt thereof).
The flocculent (F) may desirably be any anionic homopolymer or anionic copolymer that contains multivalent or monovalent counterion. Typically, the multivalent or monovalent counterion containing homopolymer or copolymer would be the multivalent or monovalent salt of the copolymer. Suitably, the multivalent counterion may be formed from alkaline earth metals, group IIla metals, transition metal etc. Preferable multivalent counterions include magnesium ions, calcium ions, aluminium ions etc. Desirably, the monovalent counterion may be formed from alkali metals or ammonium. Preferable monovalent counterions include lithium ions, sodium ions, potassium ions, ammonium ions etc. Suitable homopolymers or copolymers containing multivalent counterions may include repeating units of magnesium diacrylate, calcium diacrylate and aluminium triacrylate. Suitable copolymers containing monovalent counterions include lithium acrylate, sodium acrylate, potassium acrylate and ammonium acrylate.
Desirably, the copolymer comprises repeating units of (meth)acrylamide and an ethylenically unsaturated anionic monomer contains a sodium counterion, a potassium counterion, an ammonium counterion, a calcium counterion or a magnesium counterion.
Preferably, the copolymer contains a calcium counterion. More preferably, the copolymer is of acrylamide and an ethylenically unsaturated anionic monomer containing a calcium counterion.
Typically, the multivalent or monovalent counterion is contained in the homopolymer or copolymer of the flocculent (F) in a significant amount relative to the number of repeating units of the ethylenically unsaturated anionic monomer. Normally, the molar equivalent of multivalent or monovalent counterion to repeating anionic monomer units is at least 0.10:1.
Suitably, the molar ratio equivalent may be from 0.15:1 to 1.6:1, normally from 0.20:1 to 1.2:1, preferably from 0.25:1 to 1:1.
The multivalent or monovalent counterion containing copolymer may be obtainable by copolymerisation of ethylenically unsaturated anionic monomer which is already in association with the multivalent or monovalent counterion, for instance multivalent or monovalent cation salts of ethylenically unsaturated anionic monomer with (meth)acrylamide.

Date Recue/Date Received 2022-03-14 BASF SE

Thus, the multivalent or monovalent counterion containing copolymer, may be derived from a monomer mixture comprising a multivalent or monovalent cation salt of an ethylenically unsaturated anionic monomer and (meth)acrylamide. The ethylenically unsaturated anionic monomer salt may be present in an amount in the range of from 5% to 95% by weight, based on the total weight of the monomers. Desirably, the amounts of the respective monomers used to form the copolymer may be, for instance, from 5% to 95% by weight of multivalent or monovalent cation salt of an ethylenically unsaturated anionic monomer; and from 5% to 95% by weight of (meth) acrylamide.
Preferably, the amount of multivalent or monovalent cation salt of the ethylenically unsaturated anionic monomer may be from 5% to 85% by weight, such as from 5%
to 70%
by weight, typically from 10% to 60% by weight, often from 15% to 50% by weight, desirably from 20% to 45% by weight, for instance from 25% to 40% by weight; and the amount of (meth)acrylamide may be from 50% to 95% by weight, such as 30% to 95% by weight, typically from 40% to 90% by weight, often from 50% to 85% by weight, desirably from 55%
to 80% by weight, for instance from 60% to 75% by weight.
The flocculent (F) may desirably be a polymer in any suitable physical form.
The polymer may for instance be provided as a powder, beads, reverse-phase emulsion, liquid dispersion product, an aqueous dispersion product, aqueous gel or an aqueous solution.
Powdered polymer products are generally produced by carrying out an aqueous gel polymerisation of an aqueous solution of water-soluble ethylenically unsaturated monomers, typically at a concentration of between 10% and 45% by weight, and in which the copolymer formed therefrom is in the form of an aqueous gel. Suitably such aqueous gel can be cut into smaller pieces, dried by heating and then ground to a powder. An aqueous gel product may be produced analogously but without heating or grinding. Beads can be produced by a reverse-phase suspension polymerisation of aqueous monomer droplets, typically having a monomer concentration of between 20 and 60% by weight, suspended in a nonaqueous liquid during the polymerisation. Traditionally the droplets would be subject to stirring in order to maintain the buoyancy of the polymerising beads. The so formed beads can then be dried.
Reverse-phase emulsion polymer products are produced by a reverse-phase emulsion polymerisation process in which aqueous monomer, typically having a monomer concentration of between 20% and 60% by wt., is emulsified into a nonaqueous liquid and subjected to polymerising conditions thereby resulting in a reverse-phase emulsion polymer product. A
liquid dispersion product may be produced similarly to the reverse-phase emulsion but involving dehydration and resulting in a much higher polymer solids. An aqueous solution product may Date Recue/Date Received 2022-03-14 BASF SE

be produced by polymerising an aqueous solution of the monomer to a low molecular weight such that the final product exists as a liquid rather than a gel. In whichever form the polymer is produced, typically the polymer would be dissolved to form a dilute aqueous solution immediately prior to use, for instance at a concentration of between 0.1% by weight and 5%
by weight, suitably from 0.2% by weight to 2% by weight, generally from 0.3%
by weight to 1% by weight.
Preferably, polymerisation is effected by reacting the aforementioned monomer mixture using redox initiators and/or thermal initiators. Typically, redox initiators include a reducing agent such as sodium sulphite, sodium metabisulphite, sulphur dioxide and an oxidising compound such as ammonium persulphate or a suitable peroxy compound, such as tertiary butyl hydroperoxide etc. Redox initiation may employ up to 10,000 ppm (based on weight of aqueous monomer) of each component of the redox couple. Preferably though, each component of the redox couple is often less than 1000 ppm, typically in the range from 1 to 100 ppm, normally in the range from 4 to 50 ppm. The ratio of reducing agent to oxidising agent may be from 10:1 to 1:10, preferably in the range from 5:1 to 1:5, more preferably from 2:1 to 1:2 for instance around 1:1.
The polymerisation of the monomer mixture may be conducted by employing a thermal initiator alone or in combination with other initiator systems, for instance redox initiators.
Thermal initiators would include suitable initiator compound that releases radicals at an elevated temperature, for instance azo compounds, such as azobisisobutyronintrile (AIBN), 4,4'-azo bis-(4-cyanovalereic acid) (ACVA). Typically, thermal initiators are used in an amount of up to 10,000 ppm, based on weight of aqueous monomer. In most cases, however, thermal initiators are used in the range from 100 to 5000 ppm, preferably from 200 to 2000 ppm, more preferably from 300 to 700 ppm, usually around from 400 to 600 ppm, based on the weight of the aqueous monomer mixture.
Typical methods of preparation of the multivalent or monovalent counterion containing copolymer are given in WO 2017084986.
Intrinsic viscosity of the flocculent (F) may be determined by first preparing a stock solution.
This may be achieved by placing 1.0 g of copolymer in a bottle and adding 199 ml of deionised water. This mixture may then be mixed for 4 hours, for instance on a tumble wheel, at ambient temperature (25 C). Diluted solutions may then be prepared by, for instance, taking 0.0g, 4.0 g, 8.0 g, 12.0 g and 16.0 g, respectively, of the aforementioned stock solution and placing each into 100 ml volumetric flasks. In each case, 50 ml of sodium Date Recue/Date Received 2022-03-14 BASF SE

chloride solution (2 M) should then be added by pipette and the flask then filled to the 100 ml mark with deionised water and in each case the mixtures shaken for five minutes until homogenous. In each case, the respective diluted copolymer solutions are in turn transferred to an Ubbelohde viscometer and the measurement carried out at 25 C with the capillary viscometer Lauda iVisc. As such, the reduced specific viscosity of each of the dilute solution may be calculated and then extrapolated to determine the intrinsic viscosity of the polymer, as described in the literature.
Suitably, flocculent (F) may have an intrinsic viscosity in the range of from 5 to 30 dl/g, desirably from 5 to 25 dl/g, such as from 6 to 20 dl/g, for instance from 7 to 20 dl/g, often from 9 to 19 dl/g, typically from 10 to 18 dl/g, normally from 12 to 18 dl/g.
In one preferred form, the flocculent (F) is water-soluble. By water-soluble we mean that the polymer has a gel content measurement of less than 50% gel. The gel content measurement is described below.
The gel content may be determined by filtering a stock solution (preparation of a stock solution is described above in the method of measuring intrinsic viscosity) through a sieve with a 190 pm mesh size. The residue which stays in the filter is washed, recovered, dried (110 C) and weighed, and the percentage of undissolved polymer is calculated (weight of dry residue from the filter [g] /weight of dry polymer before filtration [g]).
Where necessary, this provides a quantifiable confirmation of the visual solubility evaluation.
Typical doses of the flocculent (F) may range from 20 to 2000 g of polymer per tonne of solids content of the aqueous slurry. Desirably, this may be from 40 or 50 to 1500 g per tonne, suitably from 75 to 1000 g per tonne, often from 90 to 750 g per tonne, usually from 100 to 500 g per tonne. The exact doses of the flocculent (F) may depend on the particular aqueous slurry, including the particular particulate mineral material of the slurry and the solids content of the slurry.
It would not normally be considered necessary to employ additives other than the at least one clay decoagulant reagent (DGR) or at least one flocculent (F) but the present invention contemplates the possibility that in certain circumstances it may be desirable to do so. For instance, it may be desirable to add other additives, such as clarification aids or coagulants.
One possibility, were considered desirable, would be to add a cationic coagulant.

Date Recue/Date Received 2022-03-14 BASF SE

Such cationic coagulant may desirably be a polymeric material having a weight average molar mass of from 10,000 to 2 million g/mol. Suitable polymers include polymers of diallyl dialkyl ammonium halide, for instance the homopolymers of diallyl dimethyl ammonium chloride (DADMAC). Suitable polymers may be formed from other cationic monomers such as quaternary ammonium salts of acrylate esters, for instance quaternary ammonium salts of dialkyl amino alkyl (meth) acrylate, such as the methyl chloride quaternary ammonium salt of dimethyl amino ethyl acrylate (DMAEA-q) or the methyl chloride quaternary ammonium salt of dimethyl amino ethyl methacrylate (DMAEMA-q). Further suitable polymers may be formed from cationic monomers based on the quaternary ammonium salts of amino alkyl acrylamides, including the quaternary ammonium salts of dialkyl amino alkyl (meth) acrylamides, for instance acrylamido propyl trimethylammonium chloride (APTAC) or methacrylamido propyl trimethylammonium chloride (MAPTAC). The aforesaid cationic monomers may be as homopolymers or as copolymers, for instance copolymers with acrylamide, such as DADMAC acrylamide copolymers, APTAC acrylamide copolymers, MAPTAC acrylamide copolymers, DMAEA-q acrylamide copolymers, and DMAEMA-q acrylamide copolymers.
Other suitable polymers for use as cationic coagulants include polyamines, for instance partially or fully hydrolysed polyvinyl formamides containing repeating vinyl amine units.
Other polymers include polyethyleneimines, polymers of alkyl amines with formaldehyde and/or epichlorohydrin, and polycyandiamides.
If it is considered necessary to add a cationic coagulant, it may be applied to the aqueous suspension in doses in the ranges from 10 to 1000 g/tonne based on active weight of coagulant on dry weight of aqueous slurry, for instance in the range of from 25 to 750 g/tonne, or from 50 to 500 g/tonne, or from 100 to 250 g/tonne.
The at least one conditioned tailings stream (CTR) should be fed to a location where the solids can be separated. Generally, the at least one conditioned tailings stream (CTR) should undergo separation into a solid rich phase and a solids depleted liquor. This is often referred to as dewatering and can be carried out by, for instance, sedimentation, gravity filtration, vacuum filtration or pressure dewatering, such as pressure filtration or centrifugation. The at least one conditioned tailings stream (CTR) may be fed to a deposition area where the at least one conditioned tailings stream (CTR) may undergo solid liquid separation. This may be on a beached surface, for instance by a tailings pond or dam, in a pit, in a trough or in a sedimentation cell.

Date Recue/Date Received 2022-03-14 BASF SE

In a first illustration of the invention a tailings slurry (TS) is treated according to the method of the invention in a device or flowchart depicted by Figure 1. A tailings slurry (TS) is formed from a combination of a sand depleted tailings slurry, such as oil sands mature fines tailings (MFT) and oil sands whole tailings (WT) to provide a tailings slurry with a sand to fines ratio (SFR) between 0.5:1 and 5:1 (not shown). The tailings slurry (TS) is pumped along a feed line by means of a pump (P) as first mass flow (MSI) into a vessel within which there is a first mixing region (MRI) which is equipped with an agitation means (AGI) which forms part of a dynamic mixer with a rotating mixing element. A clay decoagulant reagent (DGR) is pumped along a feed line by means of a pump (P) into the tailings slurry (TS) in the first mass flow (MSI) and/or first mixing region (MRI). The tailings slurry (TS) of the first mass flow (MSI) into in which the clay decoagulant reagent (DGR) has been added flows along the feed line into the first mixing region (MRI). The tailings slurry (TS) is fed from the first mixing region (MRI) as a second mass flow (M52) into a separate vessel containing the second mixing region (MR2). The second mixing region (MR2) is equipped with an agitation means (AG2) which forms part of a dynamic mixer with a rotating mixing element. A
flocculent (F) is pumped along a feed line, by means of a pump (P) into the tailings slurry (TS) in the first mass flow (MSI) and/or first mixing region (MRI) and/or second mass flow (MSI) and/or second mixing region (MR2). After the tailings slurry (TS) has been mixed within the second mixing region (MR2) it is fed along a feed line as a conditioned tailings stream (CTR) where it can be allowed to undergo separation into a solid rich phase and a solids depleted liquor. This can be in a suitable separation device, such as a pressure filtration device or a centrifuge, or deposition area in which the conditioned tailings stream (CTR) may undergo solid liquid separation, such as a beached surface, a pit or trough or sedimentation cell. The method employs according to one or more embodiments the present invention at least one item of information (11) associated with the first mass flow (MSI) and is directly or indirectly selected from at least one of the group consisting of sand to fines ratio (SFR), the solids content, the specific gravity, the clay content and the flow rate of the tailings slurry (TS) in the first mass flow (MSI); optionally at least one item of information (12) associated with the second mass flow (M52) and associated with changes to the structure of the second mass flow (M52); at least one item of information (13) associated with the fluidity measurements (FM1) showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MRI) to exiting the at least one first mixing region (MRI);
at least one item of information (14) associated with fluidity measurements (FM2) showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2); at least one item of information (15) associated with (15a) the at least one conditioned tailings stream (CTR);
and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated Date Recue/Date Received 2022-03-14 BASF SE

therefrom, wherein (15a) is associated with changes to the structure of the conditioned tailings stream (CTR) and (I5b) is associated with changes in at least one of the group selected from solids/liquid separation rate; volume of released liquid;
turbidity of released liquid; and moisture content of separated solids. The respective items of information are used to control the method in accordance with the description of the present invention.
In a second illustration of the invention a tailings slurry (TS) is treated according to the method of the invention in a device or flowchart depicted by Figure 2A. The device is analogous to the device of the first illustration except that the first mixing region (MR1) and second mixing region (MR2) are contained in a single vessel each mixing region separated by an orifice plate, wherein the second mass flow (M52) occurs through the orifice of the orifice plate and the means for collecting the item of information (12) associated with the second mass flow (M52) is located at the orifice.
In a third illustration of the invention it may be desirable for the tailings slurry (TS), for instance provided according to the first illustration, to be divided into 2 or more streams, each as independent first mass flows (MS1) independently flowing into separate vessels, or other containments, within each there are first mixing regions (MR1) which are each equipped with agitation means (AG1) which can each form part of dynamic mixers with rotating mixing elements, for alternative the other agitation means. In this case the clay decoagulant reagent (DGR) would be pumped along feed lines by means of pumps (P) into each of the respective first mass flows (MS1) and/or each of the respective first mixing regions (MR1). It may be desirable to transfer the tailings slurry (TS) from each respective first mixing regions (MR1) in second mass flows (M52) into respective separate mixing regions (MR2) which are each equipped with agitation means (AG2) which similarly can be part of dynamic mixers with rotating mixing elements. Flocculent (F) can be fed to any or any combination of each of the separate first mass flows (MS1) and/or first mixing regions (MR1) and/or second mass flows (M52) and/or second mixing regions (MR2). Separate conditioned tailings streams (CTR) can be produced by operating the process by dividing the tailings slurry (TS) into 2 or more streams, each stream being treated separately and in parallel according to the inventive process. In each case the process can be controlled in the same manner as described above and as described in the first illustration.
In a fourth illustration of the invention a tailings slurry (TS) is treated according to the method of the invention in a device or flowchart depicted by Figure 2B. The device is analogous to the device of the second illustration except that the first mixing region (MR1) and second Date Recue/Date Received 2022-03-14 BASF SE

mixing region (MR2) are separated by constriction. The means for collecting the item of information (12) associated with the second mass flow (M52) is located in the constriction.
In a fifth illustration of the invention a tailings slurry (TS) is treated according to the method of the invention in a device or flowchart depicted by Figure 5. The device is analogous to the device of the first illustration except that there is only one mixing region defined as first mixing region (MRI). The Dynamic In-Line Mixer containing the first mixing region (MRI) is a flow through mechanically agitated tank vessel. The fluidity measurements (FM
1/1 to FM
1/4) are taken by sensors (OPMI) at 4 positions on the side wall and the items of information (13) are transmitted to the Programmable Logic Controller (PLC). Item of information (11) is gathered on the tailings slurry (TS) and transmitted to the Programmable Logic Controller (PLC). The Conditioned Tailings Stream (CTR) is flowed from the first mixing region (MRI) where at least one item of information (15) (not shown) is gathered. The PLC
transmits instructions to the agitation means (AGI), the tailings slurry (TS) feed pump, the flocculent (F) feed pump and the decoagulant reagent (DGR) feed pump.
In a sixth illustration of the invention a tailings slurry (TS) is treated according to the method of the invention in a device or flowchart depicted by Figure 6. The device is analogous to the device of the fifth illustration except that the first mixing region (MRI) is in a static mixer which contains sensors that gather fluidity measurements (FM1), the tailings slurry (TS) leaving the first mixing region (MRI) flows in a second mass flow (M52) to a second mixing region (MR2) which is located in a Dynamic In Line Mixer which is a mechanically agitated tank vessel containing agitation means (AG2) to which sensors measuring fluidity measurements (FM2) are located at 4 positions. The fluidity measurements (FM1) and (FM2) are transmitted as items of information (13) and (14) to the Programmable Logic Controller (PLC).
The method of the present invention may employ the measured and calculated data inputs involving a combination of two control loops, one designed to make larger and rapid changes (Coarse Control Loop), and a second designed to make small and gradual incremental changes (Fine Control Loop) to the reagent dosing and applied mixing energy.
This may best be visualised by reference to the flow sheet shown in Figure 1. In both cases, the process control system utilises mass proportional dosing of both reagents (clay decoagulant reagent (DGR) and flocculent (F)), such that amount of reagent added to the tailings slurry (TS) is constantly adjusted to maintain the required ratio of reagents to the quantity of dry solids contained in first mass flow (MSI).
Date Recue/Date Received 2022-03-14 BASF SE

A Coarse Control Loop (CCL) may be defined as a process control loop which predominates during the initial start-up of the tailings treatment operation and whenever there are significant and rapid changes in the tailings slurry (TS) identified in the item of information

(11) data. For instance, this could be changes in the one or more of: solids content;
volumetric flow, sand to fines ratio (SFR) or clay content of the tailings slurry (TS) and/or first mass flow (MS1).
Specifically, the following could be established:
i Based on the 11 data, the initial optimal clay decoagulant reagent (DGR) dosage (g/t) is selected from the pre-defined multi-dimensional matrix (an example of this can be seen in examples 1 and 2 herein) for a tailings slurry (TS) at a specific tailings disposal facility.
ii Based on the 11 data, the initial optimal F dosage (g/t) is selected from the pre-defined multi-dimensional matrix (reference to examples 1 and 2) for this tailings slurry (TS) at the tailings disposal facility.
iii Based on the 13 data, adjust the applied mixing energy to the agitation means (AGI) to optimise fluidity measurements (FM1) outputs towards equipment specific target values.
(Note ¨ as these values will be specific to the exact engineering design of first mixing region (MR1) and a particular site configuration, these target values will be determined by initial test work during the commissioning of the equipment and the process control system).
iv Based on the 14 data, adjust the applied mixing energy to the agitation means (AG2) to optimise fluidity measurements (FM2) outputs towards equipment specific target values.
(Note ¨ as these values will be specific to the exact engineering design of first mixing region (MR1) and a particular site configuration, these target values will be determined by initial test work during the commissioning of the equipment and the process control system).
A Fine Control Loop (FCL) may be defined as a process control loop which predominates when the item of information (II) data is in steady-state or only minor fluctuations are occurring within this data set. Typically, this would mean no or only minor fluctuations or changes in one or more of: solids content, volumetric control, sand to fines ratio (SFR) or clay content of the tailings slurry (TS) and/or first mass flow (MS1). The Fine Control Loop (FCL) may be established as follows:
i Based on 15 data, small incremental changes are made to the flocculent (F) dosage (g/t) on a longer period feedback loop (for example, change dose set point by 2%, monitor 15 data for response (typically 15 minutes), make further adjustments as necessary. As examples;

Date Recue/Date Received 2022-03-14 BASF SE

a. when the conditioned tailings stream (CTR) properties (15) data are adequate, decrease flocculent (F) dose to reduce cost b. when average particle size in conditioned tailings stream (CTR) is too low, increase flocculent (F) dosage c. when release water solids are too high, increase flocculent (F) dosage ii Based on 12 data, small incremental changes are made to the mixing energy in first mixing region (MRI) by adjusting the agitation means (AGI) iii Based on 15 data, small incremental changes are made to the mixing energy in second mixing region (MR2) agitation means (AG2) The Fine Control Loop (FCL) logic may typically use prioritisation criteria based on different components of the 15 data to determine which parameter to change ¨ for example, if conditioned tailings stream (CTR) release water solids are adequate but conditioned tailings stream (CTR) average particle size is too low, then reducing mixing energy in the second mixing region (MR2) effectively reducing the mixing provided by the agitation means (AG2) would correct the particle size. However, if conditioned tailings stream (CTR) release water solids are high and conditioned tailings stream (CTR) average particle size is too low, then increasing flocculent (F) dosage would typically be desirable to improve both parameters.
On some sites/tailings disposal operations, the site-specific set-up may allow the process control system to also control the blending of the tailings slurry (TS) from different tailings slurries to form a first mass flow (MS1).
The predominantly coarse tailings slurry may be pumped directly from the bitumen extraction plant at an oilsands operation. The composition and flow rate of the coarse tailings slurry (TS) would be outside of the control of the tailings disposal operation and is mainly dictated by the operation of the extraction plant. The predominantly fine tailings stream is mature fines tailings (MFT) recovered from a tailings pond. The mature fines tailings (MFT) would have been transferred into a holding tank or intermediate pond, then pumped into the coarse tailings line to adjust the sand to fines ratio (SFR) of the tailings slurry (TS). Process water may also be pumped into the coarse tailings slurries to adjust the overall solids content of the blended tailings slurry (TS).
In this case, the 11 data may include separately measuring compositional parameters (for example solids content, volumetric flow, sand to fines ratio (SFR) or clay content) on the coarse and fine tailings slurries. The process control system then should control the pumping/addition rates for both the mature fines tailings (MFT) and the process water, Date Recue/Date Received 2022-03-14 BASF SE

varying the amount of each added in order to reduce the variability of the composition of first mass flow (MS1). Therefore, when the control of the conditioning process is applied (this is illustrated in example 4) the frequency at which the Coarse Control Loop (CCL) that would be required would be reduced, allowing the conditioning process to operate more under steady state conditions utilising the Fine Control Loop (FCL) and improving the overall efficiency of the tailings conditioning and disposal operation.

Date Recue/Date Received 2022-03-14 BASF SE

Examples The De-Coagulant Reagent (DGR) used in all examples is a terpolymer of vinyloxybutyl polyethylene glycol (adduct of 129 moles of ethylene oxide with 4-hydroxy butyl mono vinyl ether) with acrylic acid and maleic anhydride. The molar ratio of these monomers is 1/4/0.6 and the weight average molar mass approximately 53,500 g/mole. The preparation of the polymer was as described in US 2012/0035301 on page 4 under heading Polymer 1.
It is added to the Tailings Slurry (TS) in the form of a 1.0% aqueous solution.
The Flocculent used in all examples is a copolymer of calcium diacrylate and acrylamide having a weight ratio of 40/60 and exhibiting an intrinsic viscosity of 15 dl/g in the form of a powder and prepared according to W02017084986, in particular the examples, including Example 1. It is added to the Tailings Slurry in the form of a 0.5% aqueous solution.
Oi!sands process water, as used below, typically has a similar chemical composition to the aqueous phase of the MFT (mature fines tailings) slurry used to prepare the test substrate.
Example 1 TS substrate samples were prepared with various SFR (sand/fines ratio) by blending MFT
with coarse tailings and process water from a Canadian oilsands operation at varying ratios to yield a combined tailings material as required for the following small scale batch testing.
Note, as both the MFT and the coarse tailings contain a small proportion of sands and fines respectively, the final calculation of the SFR takes account of sand and fines from both materials.
Each blend of TS was mixed continuously to ensure homogeneity, and sub-sampled into individual aliquots (50 g) for subsequent testing.
Part A ¨ testing for substrate dewaterability and consolidation:
De-coagulant Reagent (DGR) solution was prepared to contain 0.5 %wt./vol of polymer in oilsands process water. Flocculent (F) solution was prepared to contain 0.5 %wt./vol of polymer in oilsands process water.
A 50 g aliquot of the TS is placed in a 120 ml beaker and mixed with a flat blade stirrer at 400 rpm. After 10 seconds, the required amount of DGR solution is added and subsequently, Date Recue/Date Received 2022-03-14 after 10 seconds, the required amount of F solution is added, and mixing is continued until the sample is conditioned to the visual point of optimum flocculation / net water release, at which time the mixer is stopped. The mixing time after the flocculent addition required to reach the point of optimum conditioning is recorded, and it may differ significantly for different types and dosages of de-coagulant and flocculent.
After conditioning, the treated substrate is transferred into a pressure filter apparatus consisting of a cylindrical chamber of diameter 3.25 cm, fitted with fine filter media at one end, and a solid sliding piston at the other. (see Figure 4). A force equal to an internal pressure of 6 psi is then applied to the piston for a period of 10 mins, during which the water expelled through the filter media is collected. The particulate solids content of the release water is determined gravimetrically by drying at 110 C for 2 hrs. The dry weight value obtained is adjusted for the electrolyte content of the process water (0.27 %wt./vol). The moisture content of the filter cake is determined by drying at 110 C for 24 hours.
Part B ¨ testing for fines capture during sub-aqueous deposition 50 g aliquot of the TS is treated with DGR and F as has been previously described in Part A.
After conditioning, the treated substrate is transferred into a 250 ml measuring cylinder which already contains 200 ml of water. The cylinder is then inverted vigorously three times to disperse the treated substrate into the bulk of the water. The cylinder is then left to stand for 10 mins before sampling the supernatant water and measuring the residual turbidity.
Optimised dewatering performance is demonstrated by high filter-cake solids and low levels of particulates in both the release water (Part A) and the supernatant water (Part B).
Table 1 Part A Part B
TS DGR Flocculent TS Mixing Cake Filtrate Mixing Solids Dose Dose Turbidity SFR Time Solids Solids Time (% wt.) (g/t (g/t) (NTU) (5) (% wt.) (% wt.) (5) 0 720 22.8 49.0 0.7 21.6 3980 280 720 25.6 58.0 1.3 26.5 933 0 800 22.2 54.1 1.2 24.1 1214 50.0 0.97 50 800 22.1 53.3 1.2 29.6 838 150 800 24.8 59.3 1.0 27.7 579 280 800 30.9 65.8 0.8 33.1 323 Date Recue/Date Received 2022-03-14 0 360 12.3 62.7 2.1 12.3 2812 50 360 11.9 75.0 1.2 11.3 2080 150 360 11.7 70.3 1.3 12.6 1690 50.0 1.75 200 360 14.9 76.1 0.9 12.0 954 0 400 12.0 65.5 1.4 14.4 1600 200 400 15.9 75.1 0.8 15.8 339 0 150 8.8 67.4 3.6 7.2 6047 50 150 9.1 67.8 2.8 8.6 4750 100 150 9.1 76.1 1.7 9.1 5390 50.0 2.98 150 150 8.1 77.2 1.1 8.1 3230 0 200 9.2 77.0 1.6 11.7 1040 150 200 12.9 75.4 1.0 8.7 300 Example 2 The following tests were conducted as described in Example 1 (Part A) utilising MFT, coarse sand tailings and process water from an alternative oilsands operation.
Table 2 Part A
TS DGR Flocculent TS Cake Filtrate SFR
Solids Dose Dose Mixing (% wt.) (g/t (g/t) Time (s) Solids (%
Solids (%
wt.) wt.) 35.0 2.0 0 286 17.0 67.4 0.61 35.0 2.0 114 286 16.0 78.0 0.57 35.0 2.0 171 286 13.0 75.3 0.65 35.0 2.0 229 286 15.0 75.0 0.57 50.0 2.0 0 400 13.0 71.9 0.74 50.0 2.0 40 400 12.0 75.5 0.94 50.0 2.0 120 400 12.0 76.6 0.75 50.0 2.0 200 400 12.0 75.6 0.83 The data in Examples 1 and 2 (Tables 1 and 2) show how the optimum dosage of DGR and F will vary with the composition of the TS, especially with respect to the SFR
and solids content. It is also known within the oilsands industry that fines and sand from different mine sites will change the dosages of reagents required to optimally condition the TS. As demonstrated in example 1, utilising laboratory test data generated with tailings samples from, a particular mining operation, a multi-dimensional matrix, with many more data points Date Recue/Date Received 2022-03-14 BASF SE

than have been determined in the above examples, can be generated and used to estimate the initial set points for DGR and F dosing, against the measured and calculated TS
compositional information 11.
Example 3 - Single Mixing Region - Dynamic In-line Mixer Configuration:
Tailings slurry (TS) is prepared at 2:1 SFR as a bulk feed in a suitable agitated tank by blending MFT, sand and process water from a Canadian oilsands operation. The tailings substrate is pumped at a controlled rate from the feed tank into the chemical treatment and conditioning process. The PLC (programable logic controller) monitors and records the output from all the process instrumentation at a suitable frequency (e.g. 1 Hz) which is then used to determine/control the set-points for all the motor drives (pumps and agitator).
For the purposes of this example, as the feed tailings slurry is batched prepared and fed from a homogenised tank, the compositional aspects of the 13 data are not expected to vary significantly throughout each test run. Therefore, the required dosage of DGR
and F are programmed as constant target set point in the PLC, based on the optimal values which had been pre-determined by small scale bench testing, as described in Example 1.
In a full scale operation, the composition of the TS is expected to vary significantly with up-stream process variations, in which case the set points for the DGR and F dosages will be varied according to predefine algorithms which have been determine by bench testing for that particular substrate, as described in Example 1.
The volume and mass flow rate (II) of the TS (Tailings Slurry) are measured using a Coriolis flow meter and the data is processed in the PLC (programable logic controller) and used to:
1. Control the TS feed pump to maintain the required volume flow rate based on the manual set-point.
2. Calculate the TS density and solids concentration (based on the ratio of mass/volume flow and the known absolute density of the solids ¨ 2,600 kg/m3) 3. Control the DGR (De-Coagulant Reagent) dosing pump to the required speed to achieve the DGR dose rate based on the manual set-point (50 g/t dry solids), the measured mass flow rate and the calculated TS solids concentration.
4. Control the F (Flocculent Reagent) dosing pump to the required speed to achieve the F
dose rate based on the manual set-point (720 g/t dry solids), the measured mass flow rate and the TS solids concentration.

Date Recue/Date Received 2022-03-14 The Dynamic In-Line Mixer (MR1) is a flow through mechanically agitated tank reactor. The internal process pressure is measured (OPM1) at four positions on the side wall and transmitted to the PLC (13). The process equipment is configured as shown in Figure 5.
In these examples, the CTR (Conditioned Tailings Stream) is visually assessed and sampled during each test run to measure the dewaterability of the treated tailings using a method similar to that described in Part A, example 1: A sample of the treated substrate is transferred into a pressure filter apparatus consisting of a cylindrical chamber of diameter 3.25 cm, fitted with fine filter media at one end, and a solid sliding piston at the other. (see __ Figure 4). A force equal to an internal pressure of 6 psi is then applied to the piston for a period of 5 mins, during which the water expelled through the filter media is collected. The particulate solids content of the release water is determined gravimetrically by drying at 110 C for 2 hrs. The moisture content of the filter-cake is determined by drying at 110 C for 24 hours.
In this example, the agitator (AG1) speed (RPM) in MR1 is a manual set-point, to demonstrate how the performance of the conditioning process varies with mixing energy and may be controlled to an optimum by monitoring the pressure (OPM1 ¨13) in MR1.
The process data shown in Table 1 and Table 2 are average values from data sampling at a frequency of 1 Hz, and a run time of several minutes for each of the different measurements.
Table 3: Substrate Feed Set Point 6 litre/min MR1 /AG1 (RPM) 75 100 150 200 300 500 (kg/min) 7.618 7.652 7.640 7.628 7.625 7.620 TS Flow (Litres/min) 5.996 6.001 6.001 5.999 6.000 6.001 L/min co = TS-SG (kg/m3) 1270 1275 1273 1272 1271 1270 a TS Solids (% w/w) 34.6 35A 34.9 34.7 34.6 34.5 42 DGR - Flow (L/min) 0.013 0.013 0.013 0.013 0.013 0.013 cu a DGR - Dose (g/t) 49 48 49 49 49 49 _ F - Flow (L/min) 0380 0.387 0.385 0380 0380 0379 F - Dose (g/t) 721 720 722 718 720 721 OPM1/1 (mbar) 184 139 155 112 68 102 2 OPM1/2 (mbar) 168 125 140 96 59 85 cu OPM1/3 (mbar) 143 117 127 87 49 77 or) _ OPM1/4 (mbar) 144 91 101 64 34 59 Date Recue/Date Received 2022-03-14 BASF SE

Visual* (-5 to +5) -4 -2 -1 0 2 3 cu .- Cake Solids (% w/w) 65.2 74.6 78.1 78.4 78.7 77.9 cu a Solids in LO
- Released (% w/w) 0.63 0.325 0.116 0.096 0.143 0.363 Water Table 4: Substrate Feed Set Point 9 litre/min MR1 /AG1 (RPM) 100 200 250 500 (kg/min) 11.318 11.387 1t347 1t331 TS Flow (L/min) 9.004 9.003 9.003 8.996 co = TS-SG (kg/m3) 1257 1265 1260 1260 O TS Solids (% w/w) 33.2 34.0 33.6 33.5 cu DGR - Flow (L/min) 0.019 0.020 0.019 0.019 cu a DGR - Dose (gpt) 51 52 50 50 - F - Flow (L/min) 0.542 0.569 0.549 0.547 F - Dose (g/t) 721 735 721 720 OPM1/1 (mbar) 278 238 195 207 2 OPM1/2 (mbar) 267 224 183 191 cu OPM1/3 (mbar) 204 207 185 177 or) _ OPM1/4 (mbar) 240 193 162 168 Visual* (-5 to +5) -4 -1 0 3 2 Cake Solids (% w/w) 71.4 77.3 76.7 77.0 cu a Solids in LO
- Released (% w/w) 0.106 0.095 0.091 0.117 Water *Visual assessment score; -5: very undermixed, 0: optimally mixed, +5 very overmixed (highly sheared) Table 5 - Untreated Substrate, Feed Set Point 6 litre/min MR1 /AG1 (RPM) 50 100 200 400 600 800 (kg/min) 7.664 7.653 7.657 7.669 7.666 7.659 TS Flow cu (L/min) 6.001 5.998 5.999 6.001 6.003 6.000 cu a TS-SG (kg/m3) 1277 1276 1276 1278 1277 1277 _ TS Solids (% w/w) 35.3 35.1 35.2 35.3 35.2 35.2 Date Recue/Date Received 2022-03-14 BASF SE

OPM1/1 (mbar) 203 206 211 218 231 247 OPM1/2 (mbar) 189 191 196 202 211 223 cu OPM1/3 (mbar) 184 185 190 197 206 217 OPM1/4 (mbar) 167 169 173 178 185 191 As shown in Table 5, for untreated TS flowing through MRI, the side wall pressure readings (13) would normally increase with increased agitator speed due to the additional radial energy imparted from the agitator. However, as can been seen from the data in Tables 3 and 4, for treated material, a decrease in wall pressure is initially observed as the mixing energy (AGI) increases, and optimal conditioning and dewatering are found to occur at, or just before the system pressure (13) in MRI reaches a minimum. In Table 3, optimum conditioning (Visual Rating 0) occurs, with AGI in the range of 200 to 300rpm.
In Table 4, optimum conditioning occurs with AGI in the range of 200 to 250rpm.This data enables the agitator (AGI) rotation speed to be controlled based on 13 to give optimum conditioning of the Tailings Slurry.
Example 4 Dual Mixer Region ¨ Static In-line Mixer and Dynamic In-line Mixer Configuration:
The details in this example are the same as the previous example except that the Tailings Slurry (TS) is prepared with an SFR of 1.7 and a Static In-line Mixer is used (MRI) is a helical element inserted into a 12.5mm ID pipe, with a total length of approximate 300mm.
The pressure drop across the in-line mixer is measured (OPMI) and transmitted to the PLC
(13). The Dynamic In-Line Mixer (MR2) is the same as described in the previous example.
The process equipment is configured as shown in Figure 6.
The volume and mass flow rate (11) of the TS (Tailings Slurry) is measured using a Coriolis flow meter and the data is processed in the PLC (programable logic controller) and used to:
1. Control the TS feed pump to maintain the required volume flow rate based on the manual set-point.
2. Calculate the TS density and solids concentration (based on the ratio of mass/volume flow and the known absolute density of the solids ¨ 2,600 kg/m3) 3. Control the DGR (De-Coagulant Reagent) dosing pump to the required speed to achieve the DGR dose rate based on the manual set-point (50 g/t dry solids), the measured mass flow rate and the calculated TS solids concentration.
Date Recue/Date Received 2022-03-14 4. Control the F (Flocculent Reagent) dosing pump to the required speed to achieve the F
dose rate based on the manual set-point (720 g/t dry solids), the measured mass flow rate and the TS solids concentration.
In this example, the agitator speed (RPM) in MR2 is a manual set-point which is varied to demonstrate how the performance of the conditioning process varies with mixing energy and may be controlled to an optimum by monitoring the pressure (OPM2 -14) in MR2.
Table 6: Substrate Feed Set Point 6 litre/min MR2 / AG2 (RPM) 0 25 50 75 100 200 (kg/min) 7.358 7.375 7409 7.282 7.341 7.293 TS Flow (L/min) 5.995 5.999 6.009 5.997 6.002 5.991 TS-SG (kg/m3) 1.227 1229 1.233 1214 1223 0_ 45' TS Solids (% w/w) 30.1 30.3 30.7 28.7 29.6 29.0 cu DGR - Flow (L/min) 0.011 0.011 0.011 0.010 0.011 0.011 ru a DGR - Dose (g/t) 50 49 48 48 51 52 F - Flow (L/min) 0.320 0.321 0.329 0.300 0.315 0.306 F - Dose (g/t) 723 719 722 720 725 725 AP (mbar) 910 902 919 857 887 867 OPM2/1 (mbar) 553 415 280 220 244 202 OPM2/2 (mbar) 226 367 240 194 216 186 cu OPM2/3 (mbar) 195 317 202 182 200 181 OPM2/4 (mbar) 176 260 169 160 178 164 Visual* (-5 to -2 -1 0 1 1 2 +5) g Cake Solids (% w/w) 70.4 77.3 76.9 75.91 76.2 76.6 . .
LO Solids in - Released (% w/w) 0.144 0.114 0.122 0.163 0.116 0.129 Water *Visual assessment score; -5: very undermixed, 0: optimally mixed, +5 very overmixed (highly sheared) A P is the pressure differential between the tailings slurry (TS) entering the first mixing region (MR1) and leaving the first mixing region (MR1) and hence (13) data.

Date Recue/Date Received 2022-03-14 BASF SE

Similar to the previous example, optimal conditioning (Visual Rating 0) and dewatering are shown to occur at, or just before the system pressure (14) in MR2 reaches a minimum, when AG2 is at or around 50 rpm. This enables the agitator rotation speed to be controlled based on 14 to give optimum conditioning of the Tailings Slurry.
Example 5 ¨ Process Control Decision Method For the tailings processing flow sheet shown in Figure 1, one possible method to use the measured and calculated data inputs involves a combination of two control loops, one designed to make larger and rapid changes (Coarse Control Loop), and a second designed to make small and gradual incremental changes (Fine Control Loop) to the reagent dosing and applied mixing energy. In both cases, the process control system utilises mass proportional dosing of both reagents (DGR and F), such that amount of reagent added to the TS is constantly adjusted to maintain the required ratio of reagents to the quantity of dry solids contained in MSI.
Coarse Control Loop (CCL) ¨ This process control loop predominates during process start-up and whenever significant and rapid changes are detected in II data. For example, changes in one or more of; solids content, volumetric flow, SFR or clay content of the TS/MSI.
i Based on the 11 data, the initial optimal DGR dosage (g/t) is selected from the pre-defined multi-dimensional matrix (see examples 1 and 2) for this TS at the tailings disposal facility.
ii Based on the 11 data, the initial optimal F dosage (g/t) is selected from the pre-defined multi-dimensional matrix (see examples 1 and 2) for this TS at the tailings disposal facility.
iii Based on the 13 data, adjust the applied mixing energy (AGI) to optimise FM1 outputs towards equipment specific target values. (Note ¨ as these values will be specific to the exact engineering design of MRI and site configuration, these target values will be determined by initial test work during the commissioning of the equipment and the process control system).
iv Based on the 14 data, adjust the applied mixing energy (AG2) to optimise FM2 outputs towards equipment specific target values. (Note ¨ as these values will be specific to the exact engineering design of MRI and site configuration, these target values will be determined by initial test work during the commissioning of the equipment and the process control system).

Date Recue/Date Received 2022-03-14 BASF SE

Fine Control Loop (FCL) - This process control loop predominates when the 11 data is in steady state, or only minor fluctuations are occurring in this data set. For example, changes in one or more of; solids content, volumetric flow, SFR or clay content of the TS/MSI.
i Based on 15 data, small incremental changes are made to the F dosage (g/t) on a longer period feedback loop (for example, change dose set point by 2%, monitor 15 data for response (typically 15 minutes), make further adjustments as necessary. As examples;
a. when CTR properties (15) data are adequate, decrease F dose to reduce cost b. when average particle size in CTR is too low, increase F dosage c. when release water solids are too high, increase F dosage ii Based on 12 data, small incremental changes are made to the mixing energy in MRI
(AGI) iii Based on 15 data, small incremental changes are made to the mixing energy in MR2 (AG2) The FCL logic will use prioritisation criteria based on different components of the 15 data to determine which parameter to change ¨ for example, if CTR release water solids are adequate but CTR average particle size is too low, then reducing mixing energy in MR2 (AG2) will correct the particle size. However, if CTR release water solids are high and CTR
average particle size is too low, then increasing F dosage will be necessary to improve both parameters.
Example 6¨ Process Control Improved Stability.
On some sites/tailings disposal operations, the site specific set-up may allow the process control system to also control the blending of the TS from different tailings streams to form MS1. For example.
The predominantly coarse tailings stream is pumped directly from the bitumen extraction plant at an oilsands operation. The composition and flow rate of the coarse tailings stream will be outside of the control of the tailings disposal operation and is mainly dictated by the operation of the extraction plant. The predominantly fine tailings stream is MFT recovered from a tailings pond. The MFT has been transferred into a holding tank or intermediate pond, then pumped into the coarse tailings line to adjust the SFR of the tailings slurry. Process water may also be pumped into the coarse tailings stream to adjust the overall solids content of the blended tailings slurry.

Date Recue/Date Received 2022-03-14 BASF SE

In this example, the 11 data includes separately measuring compositional parameters (for example solids content, volumetric flow, SFR or clay content) on the coarse and fine tailings streams. The process control system then controls the pumping/addition rates for both the MFT and the process water, varying the amount of each added in order to reduce the variability of the composition of MS1. Therefore, when the control of the conditioning process is applied as described in example 4, the frequency at which the CCL is required will be reduced, allowing the conditioning process to operate more under steady state conditions utilising the FCL and improving the overall efficiency of the tailings conditioning and disposal operation.

Date Recue/Date Received 2022-03-14

Claims

BASF SE

Claims

1. A method for separating solids from a tailings slurry (TS), which tailings slurry (TS) has a solids content of from 25 to 70% by weight and comprises sand particles and fines particles with a sand to fines ratio (SFR) of from 0.5:1 to 5:1, wherein the fines particles comprise clay, a. forming at least one first mass flow (MS1) of the tailings slurry (TS) entering at least one containment, which the at least one containment comprises at least one first mixing region (MR1), b. subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG1) in the at least one first mixing region (MR1), wherein fluidity measurements (FM1) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MR1) to exiting the at least one first mixing region (MR1), c. optionally flowing the tailings slurry (TS) from the at least one first mixing region (MR1) to at least one second mixing region (MR2) as at least one second mass flow (M52), said at least one second mixing region (MR2) having at least one agitation means (AG2), d. optionally subjecting the tailings slurry (TS) to mixing by the at least one agitation means (AG2) in the at least one second mixing region (MR2), wherein fluidity measurements (FM2) are taken showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), e. adding a clay de-coagulant reagent (DGR) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one first mass flow (MS1) and the at least one first mixing region (MR1), said at least one first mixing region (MR1) having at least one agitation means (AG1), f. adding a flocculent (F) to the tailings slurry (TS) in at least one place selected from the group consisting of the at least one at least one first mass flow (MS1), the first mixing region (MR1), the at least one second mass flow (M52) and the at least one second mixing region (MR2), g. flowing the tailings slurry (TS) from either or both (i) the at least one first mixing region (MR1) and/or (ii) the at least one second mixing region (MR2) as at least one conditioned tailings stream (CTR), h. separating the at least one conditioned tailings stream (CTR) into a solids rich phase and a solids depleted liquor, wherein the method comprises Date Recue/Date Received 2022-03-14 BASF SE

(A) at least one item of information (11);
(B) optionally at least one item of information (13);
(C) optionally at least one item of information (14); and (D) at least one item of information (15), wherein A. the at least one item of information (11) is associated with the at least one first mass flow (MSI) and is directly or indirectly selected from the group consisting of the sand to fines ratio (SFR); the solids content; the specific gravity; the clay content and the flow rate, B. the at least one item of information (13) is associated with the fluidity measurements (FM1) showing any change in fluidity of the tailings slurry (TS) from entering the at least one first mixing region (MRI) to exiting the at least one first mixing region (MRI), C. the at least one item of information (14) is associated with fluidity measurements (FM2) showing any change in fluidity of the tailings slurry (TS) from entering the at least one second mixing region (MR2) to exiting the at least one second mixing region (MR2), D. the at least one item of information (15) is associated with (I5a) the at least one conditioned tailings stream (CTR); and/or (I5b) components of the at least one conditioned tailings stream (CTR) separated therefrom, wherein (15a) is associated with changes to the structure of the conditioned tailings stream (CTR) and (I5b) is associated with changes in at least one of the group selected from solids/liquid separation rate;
volume of released liquid; turbidity of released liquid; and moisture content of separated solids, Characterised in that, either (I) the method comprises the at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) to mixing in the at least one first mixing region (MR1) and the at least one second mixing region (MR2) and includes subjecting the tailings slurry (TS) to mixing in the at least one second mixing region (MR2), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii), (iii) and (iv):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AGI), (iv) the initial rate of mixing provided by the at least one agitation means (AG2), and Date Recue/Date Received 2022-03-14 BASF SE

(v) reset at least one of (i) to (iv) according to said predefined conditions, in which at least one of (IA) and/or (1B) are employed, (IA) the at least one item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AGI), and/or (1B) the combination of the at least one item of information (14) and at least one item of information (15) is used to adjust the rate of mixing provided by the at least one agitation means (AG2);
and the at least one item of information (15) is used to adjust the dose of either the clay de-coagulant reagent (DGR) and/or the flocculent (F), or (II) the method employs as mixing region(s) solely at least one first mixing region (MRI) and includes subjecting the tailings slurry (TS) to mixing in the at least one first mixing region (MRI), wherein the at least one item of information (11) is used to set according to predefined conditions for the tailings slurry (TS) each of (i), (ii) and (iii):
(i) the initial dose of clay de-coagulant reagent (DGR), (ii) the initial dose of flocculent (F), (iii) the initial rate of mixing provided by the at least one agitation means (AGI), and (v) reset at least one of (i) to (iii) according to said predefined conditions;
and the combination of item of information (15) and at least one item of information (13) is used to adjust the rate of mixing provided by the at least one agitation means (AGI);
and the at least one item of information (15) is used to adjust the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F).

Date Recue/Date Received 2022-03-14 BASF SE

2. A method according to claim 1, wherein at least one item of information (12) is associated with the at least one second mass flow (MS2) and is associated with changes to the structure of the second mass flow (M52), wherein said at least one item of information (12) is used in combination with the at least one item of information (13) to adjust the rate of mixing provided by the at least one agitation means (AGI), and said at least one item of information (12) is used in combination with the at least one item of information (15) to adjust the dose of either the clay decoagulant reagent (DGR) and/or the flocculent (F).

3. A method according to claim 1 or claim 2, wherein the tailings slurry (TS) is formed by combining a multiplicity of component tailings streams and optionally a water stream.

4. A method according to any one of claims 1 to 3, wherein the method comprises combining a first tailings stream (FTS) and a second tailings stream (STS) to form the tailings slurry (TS), and in which the first tailings stream (FTS) has a lower sand to fines ratio (SFR) than the second tailings stream.

5. A method according to claim 4, wherein the first tailings stream (FTS) has a sand to fines ratio (SFR) of less than 1:1, preferably less than 0.5:1, and the second tailings stream (STS) has a sand to fines ratio (SFR) greater than 3:1, preferably greater than 5:1.

6. A method according to claim 4 or claim 5, wherein the first tailings stream (FTS) is a mature fines tailings (MFT).

7. A method according to any one of claims 4 to 6, wherein the second tailings stream (STS) is a whole tailings (WT) or underflow from a cycloned whole tailings (WT).

8. A method according to any one of claims 1 to 7, wherein the sand to fines ratio (SFR) of the tailings slurry (TS) is controlled by varying the ratio of component tailings streams, each with different sand to fines ratios (SFR), preferably in response to item of information (11).

9. A method according to any one of claims 1 to 8, wherein the flow rate of the at least one first mass flow (MS1) is controlled by adjusting the flow rate provided by a feed pump feeding the tailings slurry (TS) as the at least one first mass flow (MSI) in response to item of information (11).

Date Recue/Date Received 2022-03-14 BASF SE

10. A method according to any one of claims 1 to 9, wherein the tailings slurry (TS) flowing from the (i) at least one first mixing region (MR1) or (ii) at least one second mixing region (MR2) passes through one or more further mixing regions before exiting as the at least one conditioned tailings stream (CTR).

11. A method according to any one of claims 1 to 10, wherein the at least one containment is a vessel, pipeline or other conduit, preferably a vessel.

12. A method according to any one of claims 1 to 11, wherein the at least one containment, preferably at least one vessel, comprises a multiplicity of chambers and in which the tailings slurry (TS) progresses through each of the respective chambers in succession.

13. A method according to any one of claims 1 to 12, wherein each of the at least one first mixing region (MR1) and the optional at least one second mixing region (MR2) each independently comprises one or more chambers and in which the tailings slurry (TS) progresses through each of the respective chambers in succession, wherein the at least one agitation means (AG1) provides at least one agitation element in one or more chambers of the at least one first mixing region (MR1) and optionally the at least one agitation means (AG2) provides at least one agitation element in one or more chambers of the at least one second mixing region (MR2), and preferably the at least one first mixing region (MR1) and/or at least one second mixing region (MR2) is/are dynamic mixer(s).

14. A method according to any one of claims 1 to 13, wherein the at least one first mixing region (MR1) and the at least one second mixing region (MR2) are contained in a single vessel or a multiplicity of single vessels wherein each vessel contains a first mixing region (MR1) and a second mixing region (MR2), preferably the first mixing region (MR1) and second mixing region (MR2) are separated by an orifice plate.

15. A method according to any one of claims 1 to 13, wherein the at least one first mixing region (MR1) and the at least one second mixing region (MR2) are contained in separate vessels.

16. A method according to any one of claims 1 to 15, wherein the at least one item of information (13) associated with the fluidity measurements (FM1) is obtained through at least one sensor which measures at least one item selected from the group consisting of vibration, acoustics and pressure.

Date Recue/Date Received 2022-03-14 BASF SE

17. A method according to any one of claims 1 to 16, wherein the at least one item of information (14) associated with the fluidity measurements (FM2) is obtained through at least one sensor which measures at least one item selected from the group consisting of vibration, acoustics and pressure.

18. A method according to any one of claims 1 to 17, wherein the at least one first mixing region (MR1) is contained by a wall and wherein the at least one item of information (13) associated with the fluidity measurements (FM1) are determined by at least one-instrument which detects pressures and/or variations in pressure (OPM1) within the at least one first mixing region (MR1), suitably by detecting pressure measurements and pressure variations within the at least one first mixing region (MR1) in the region of the wall of the at least one first mixing region (MR1), said instrument being adapted to analyse the data comprising the pressure and/or variations in pressure and determine changes in fluidity.

19. A method according to any one of claims 1 to 18, wherein the at least one first mixing region (MR1) is contained by a wall and wherein the at least one item of information (13) associated with the fluidity measurements (FM1) are determined by at least one instrument which detects vibrations or acoustics and or variations in vibrations or acoustics within the at least one first mixing region (MR1), suitably by detecting vibrations or acoustics and/or variations in vibrations or acoustics within the at least one first mixing region (MR1) in the region of the wall of the at least one mixing region (MR1), said instrument being adapted to analyse the data comprising the vibrations or acoustics and/or variations in vibrations or acoustics and determine changes in fluidity.

20. A method according to any one of claims 1 to 19, wherein the at least one second mixing region (MR2) is contained by a wall and wherein the at least one item of information (14) associated with the fluidity measurements (FM2) are determined by at least one instrument which detects pressures and/or variations in pressure (OPM2) within the at least one second mixing region (MR2), suitably by detecting pressure measurements and pressure variations within the at least one second mixing region (MR2) within the region of the wall of the at least one second mixing region (MR2) said instrument being adapted to analyse the data comprising the pressure and/or variations in pressure and determine changes in fluidity.

21. A method according to any one of claims 1 to 20, wherein the at least one second mixing region (MR2) is contained by a wall and wherein the at least one item of information Date Recue/Date Received 2022-03-14 BASF SE

(14) associated with the fluidity measurements (FM2) are determined by at least one instrument which detects vibrations or acoustics and or variations in vibrations or acoustics within the at least one second mixing region (MR2), suitably by detecting vibrations or acoustics and/or variations in vibrations or acoustics within the at least one second mixing region (MR2) in the region of the wall of the at least one second mixing region (MR2), said instrument being adapted to analyse the data comprising the vibrations or acoustics and/or variations in vibrations or acoustics and determine changes in fluidity.

22. A method according to any one of claims 1 to 21, wherein the least one item of information (15a) associated with changes to the structure of the at least one conditioned tailings stream (CTR) is obtained through at least one instrument which gathers information selected from at least one item of the group consisting of tomography, imaging, vibration and acoustics.

23. A method according to any one of claims 1 to 22, wherein the at least one item of information (15a) associated with changes to the structure of the at least one conditioned tailings stream (CTR) detects if the at least one conditioned tailings stream (CTR) is exhibiting turbulent flow or substantially non-turbulent flow, wherein suitably non-turbulent flow is laminar flow.

24. A method according to any one of claims 1 to 23, wherein the at least one item of information (15a) is determined by employing an accelerometer.

25. A method according to any one of claims 1 to 24, wherein the at least one item of information (I5b) associated with components of the at least one conditioned tailings stream (CTR) is provided by an instrument adapted to take measurements associated with the separation and wherein the measurements are selected from at least one of the group consisting of separation rate, turbidity of liquor separated from the at least one conditioned tailings stream (CTR), solids content of the solid material separated from the at least one conditioned tailings stream (CTR) and moisture content of the solid material separated from the at least one conditioned tailings stream (CTR).

Date Recue/Date Received 2022-03-14