[go: up one dir, main page]

EP2509709A1 - Method and apparatus to create uniform mixing in connection with a hydrometalurgical process - Google Patents

Method and apparatus to create uniform mixing in connection with a hydrometalurgical process

Info

Publication number
EP2509709A1
EP2509709A1 EP10835537A EP10835537A EP2509709A1 EP 2509709 A1 EP2509709 A1 EP 2509709A1 EP 10835537 A EP10835537 A EP 10835537A EP 10835537 A EP10835537 A EP 10835537A EP 2509709 A1 EP2509709 A1 EP 2509709A1
Authority
EP
European Patent Office
Prior art keywords
helix
reactor
rotors
rotor
mixing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP10835537A
Other languages
German (de)
French (fr)
Other versions
EP2509709A4 (en
Inventor
Teemu Ritasalao
Jussi Vaarno
Launo Lilja
Juhani Lyyra
Pertiti Pekkala
Bror Nyman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Metso Corp
Original Assignee
Outotec Oyj
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Outotec Oyj filed Critical Outotec Oyj
Publication of EP2509709A1 publication Critical patent/EP2509709A1/en
Publication of EP2509709A4 publication Critical patent/EP2509709A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
    • B01F27/92—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with helices or screws
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/01—Separation of suspended solid particles from liquids by sedimentation using flocculating agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/02—Settling tanks with single outlets for the separated liquid
    • B01D21/08—Settling tanks with single outlets for the separated liquid provided with flocculating compartments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/28—Mechanical auxiliary equipment for acceleration of sedimentation, e.g. by vibrators or the like
    • B01D21/286—Means for gentle agitation for enhancing flocculation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/50—Mixing liquids with solids
    • B01F23/53—Mixing liquids with solids using driven stirrers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05—Stirrers
    • B01F27/11—Stirrers characterised by the configuration of the stirrers
    • B01F27/114—Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections
    • B01F27/1145—Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections ribbon shaped with an open space between the helical ribbon flight and the rotating axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05—Stirrers
    • B01F27/11—Stirrers characterised by the configuration of the stirrers
    • B01F27/114—Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections
    • B01F27/1145—Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections ribbon shaped with an open space between the helical ribbon flight and the rotating axis
    • B01F27/11451—Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections ribbon shaped with an open space between the helical ribbon flight and the rotating axis forming open frameworks or cages
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
    • B01F27/86—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis co-operating with deflectors or baffles fixed to the receptacle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
    • B01F27/92—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with helices or screws
    • B01F27/922—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with helices or screws with two or more helices, e.g. with intermeshing helices
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F11/00—Treatment of sludge; Devices therefor
    • C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
    • C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
    • C02F11/147—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using organic substances
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/34—Treatment of water, waste water, or sewage with mechanical oscillations
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2301/00—General aspects of water treatment
    • C02F2301/02—Fluid flow conditions
    • C02F2301/024—Turbulent

Definitions

  • the invention relates to a method and apparatus, enabling the mixing of one or several solutions in a hydrometallurgical process in a reactor to bring about the desired crystallisation, precipitation or suspension in solvent extraction.
  • the apparatus consists of a reactor and a multi-part helical rotor mixer placed in it, in the helical rotors of which there are helical bars rotating around the shaft and supported to it.
  • Non-homogenous mixing is a problem for many hydrometallurgical unit processes.
  • a blade or turbine type mixer often rotates in a volume in which the primary mixing zone is at most around 3 % of the total volume of the reactor that is used. This means that the shaft power produced by the mixer is directed very strongly on the immediate vicinity of the mixer.
  • the volume-specific mixing intensity around the shaft is several tens of kilowatts per cubic metre, but falls dramatically going towards the edges of the reactor.
  • a spiral mixer has been developed for providing homogenous mixing in a reactor when two liquids that are insoluble in each other or a liquid and a solid are mixed together, which is described for instance in US patent publications 5,185,081 , 5,248,485 and 5,182,087.
  • the diameter of the mixer in the apparatuses described is around 0.7 times the diameter of the reactor.
  • the mixing intensity achieved with this kind of mixer also may be too high.
  • the purpose of the method and apparatus accordant with the invention is to achieve a more homogenous mixing than earlier in conjunction with various hydrometallurgical unit processes such as during precipitation or crystallisation or in the mixing section of solvent extraction.
  • the purpose of the invention is to reduce the total power used in various unit processes while nevertheless achieving a more homogenous mixing than previously in the reactor space used. When mixing is uniform throughout the entire reactor space, neither localised peak power points nor almost dead spots will be formed.
  • the invention relates to a method for mixing one or several solutions in a reactor in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction.
  • a hydrometallurgical process such as precipitation, crystallisation or forming a suspension in solvent extraction.
  • Mixing with a vertical circulation flow is formed in the reactor by means of a multi-part mixer, so that the primary mixing zone is over 70 % of the effective volume of the reactor in order to achieve the homogenous, low-intensity mixing needed for precipitation, crystallisation and/or the mixing stage of solvent extraction.
  • the primary mixing zone is over 80 % of the effective volume of the reactor. It is typical of the method accordant with the invention that uniform mixing is achieved in the reactor using a helical rotor mixer consisting of at least three helical rotors.
  • the primary mixing zone consists of the area remaining on the inside of the helix rotor as well as an area about the size of the cross-sectional area of the helix rotor outside the helix rotor and the height of the primary mixing zone in terms of elevation is at least the same as the height of the helix rotor.
  • a flocculant is used as an agent in precipitation and/or crystallisation to flocculate the solid.
  • the invention also relates to an apparatus for mixing one or several solutions in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction.
  • the apparatus comprises a reactor, which consists of a base and a cylindrical sidewall rising upwards from the base, as well as a mixer placed in the reactor.
  • the mixer is a multi-part helix rotor mixer, which is adapted to provide homogenous mixing with a vertical circulation flow, creating a low mixing intensity, where the primary mixing zone is over 70 % of the effective volume of the reactor.
  • the helix rotor mixer comprises at least three helix rotors, which are arranged in the reactor, a power device to rotate the helix rotors, and several elongated vertical baffles projecting from the sidewall of the reactor.
  • the helix rotor comprises a vertical rotation shaft, which is connected to a power device, and two or three helix members, which are fixed to the rotation shaft with support arms that are a radius away from the rotation shaft.
  • the helix member is circular in cross-section.
  • the helix member is oval in cross- section.
  • the baffles are at an angle of 5 - 15 degrees to the radius of the reactor.
  • the baffles are preferably placed in the vicinity of each helix rotor, downstream of its rotation direction.
  • their diameter is at least 0.33 times the diameter of the reactor.
  • the apparatus when the number of helix rotors is five, their diameter is at least 0.23 times the diameter of the reactor, so that one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor.
  • a third configuration of the apparatus when the number of helix rotors is five, one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor, so that the diameter of the central helix rotor is greater than that of the rotors surrounding it.
  • the rotation shafts of the helix rotors are arranged radially in relation to the vertical central shaft of the reactor. According to one configuration of the apparatus accordant with the invention, all the helix rotors rotate in the same direction and the rotation direction of the helix members around the shaft is the same as the rotation direction of the helix rotor.
  • all the helix rotors rotate in the same direction and the rotation direction of the helix members around the shaft differs from the rotation direction of the helix rotor.
  • the central helix rotor rotates in a different direction from the helix rotors surrounding it.
  • Figure 1 presents a cross-section of one configuration of a helix rotor mixer accordant with the invention
  • Figure 2 presents the profile II - II of the mixer in Figure 1 ,
  • Figure 3 presents the corresponding profile to Figure 2 of another helix rotor mixer configuration.
  • helix rotor mixer which consists of at least three separate helix rotors.
  • the mixer is placed in a reactor that is generally an upright cylinder in shape.
  • a solution to be crystallised, a liquid containing solids, or two liquids insoluble in each other are mixed in the reactor to bring about crystallisation, precipitation or a suspension in solvent extraction.
  • the primary mixing zone of the helix rotor mixer covers over 70 %, preferably over 80 %, of the effective volume of the reactor. Effective volume means the volume in the reactor between the bottom of the reactor and the surface of the liquid.
  • the primary mixing zone consists of the area remaining within the helix rotor plus an area outside it about the size of the cross- sectional area of the helix rotor. In terms of elevation the height of the primary mixing zone is at least the same as the height of the helix rotor. Clearly, mixing also occurs outside the primary mixing zone even though the mixing intensity is lower.
  • the individual helix rotors of the helix rotor mixer are grouped so that their primary mixing zones merge with each other outside the helix rotors.
  • the helix rotor is up-pumping, it means that in this case a flow pattern is formed in which the direction of the flow within the rotor is downward and outside the rotor it is upward.
  • the flows that come from the inside of the helix rotors turn obliquely upwards outside the helix rotors and interact with each other so that they merge with each other in the space between the helix rotors.
  • the operating speed of the helix rotors is adjusted to be such that the formation of turbulence is prevented in the space between the helix rotors, but at the same time the desired effects are brought about by laminar mixing.
  • the mixing power is divided in this way to be uniform throughout the reactor, we can state that this arrangement reduces the overall energy consumption used in mixing. With this arrangement locally occurring powerful mixing forces can also be avoided and low-intensity mixing can be directed on the entire cross-section of the reactor.
  • FIG. 1 One apparatus accordant with the invention, consisting of a reactor and a mixer with three separate helix rotors, is described in more detail in Figures 1 and 2.
  • the figures show one configuration as an example, where helix rotor mixer 1 comprises three double helix rotors 7.
  • the helix rotor mixer 1 consists of reactor 3, whose interior 4 is bounded laterally by cylindrical sidewall 5 and beneath by base 6.
  • the double helix rotors 7 are arranged in interior 4 a radius away from the central shaft of the reactor in a triangular formation, as shown in Figure 2.
  • Each helix rotor 7 is rotated by a power device 8.
  • Several elongated vertical baffles 9 protrude from sidewall 5 of reactor 3.
  • Each helix rotor 7 comprises a vertical rotating shaft 10, which is connected to a power device 8, and two identical helical tubes 11 , which are circular in cross-section and are attached to rotation shaft 10 by support arms 12.
  • the helical tubes are symmetrically opposite each other at a distance of one radius from the shaft.
  • the solution or solutions to be treated can be introduced into the reactor at desired points and the result of the generated reactions removed from desired points of the reactor (not shown in detail in the drawing).
  • the diameter of the helix rotors is at least 0.33 times the diameter of the reactor and preferably around 0.35 times the diameter of the reactor.
  • All the helix rotors preferably rotate in the same direction either up-pumping or down-pumping, and in this case the direction that the helical tubes rotate around the shaft is also the same as the rotation direction. Therefore the helix rotors rotate either clockwise or anticlockwise. In most cases it is more advantageous to use a up-pumping mixing direction, so that outside the helix rotors a strong upward zone is generated at each point downstream of the baffles.
  • the upward zones merge with each other in the manner described above and intensify mixing.
  • the upward zones can be further intensified by placing the baffles closer to the helix rotors.
  • baffles 9 it is advantageous to place the baffles 9 at a distance that is 0.04 - 0.08 times the diameter of the reactor from the sidewall of the reactor and their width is preferably 0.1 - 0.13 times the diameter of the reactor. It is typical of the baffles accordant with the invention that instead of placing them radially, they are at an angle of 5 - 15 degrees from the radius.
  • the baffles are placed in the vicinity and downstream of each helix rotor, as shown in Figure 2. In this way an intensifying effect is attained on the homogenous mixing across the entire reactor.
  • the mixing intensity can be adjusted for example to the range of 0.05 - 1.5 kW/m 3 .
  • the advantage of the arrangement accordant with the invention is that localised strong primary mixing is no longer required thanks to the homogenous mixing that covers the whole reactor area.
  • FIG 3 is an illustration of a further mixer accordant with the invention, in which there are five helix rotors 7.
  • One of the helix rotors is situated in the centre of the reactor and the four others symmetrically around the central helix rotor on the circumference of the reactor.
  • the diameter of the helix rotors is at least 0.23, preferably 0.25 - 0.3 times the diameter of the reactor.
  • the arrangement accordant with Figure 3 can achieve a situation where as much as 85 % of the mixing in the reactor space is primary mixing.
  • the structural configuration accordant with Figure 3 can be changed further so that the diameter of the helix rotor situated in the central part of the reactor is greater than the diameter of the helix rotors located on the circumference of the reactor.
  • the rotation direction of all the helix rotors can be selected to be the same or the rotation direction of the centrally placed helix rotor can be selected to differ from the rotation direction of the helix rotors located on the circumference.
  • the examples above have referred to a helix rotor with two helical members only as an example. Depending on the requirements of the application the helix rotor may have two or three helical members.
  • helical member it may be some other shape than round in cross section.
  • a round bar may also be flattened, so that the profile of the helical member is oval in shape.
  • the properties of the solid to be precipitated or crystallised can be improved with homogenous mixing. Growth in particle size during solid precipitation and crystallisation can be controlled better than in apparatus where there is a powerful, narrow primary mixing.
  • a flocculant can also be used to aid the flocculation of solids.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Water Supply & Treatment (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Dispersion Chemistry (AREA)
  • Mixers Of The Rotary Stirring Type (AREA)
  • Extraction Or Liquid Replacement (AREA)
  • Separation Of Suspended Particles By Flocculating Agents (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

The invention relates to a method and apparatus for mixing one or several solutions in a reactor (3) in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction. Mixing with a vertical circulation flow is created in the reactor by means of a multi-part mixer (1), so that the primary mixing zone in which the mixer rotates is over 70 % of the effective volume of the reactor, whereby the homogenous, low-intensity mixing needed for precipitation, crystallisation and/or the mixing stage of solvent extraction is achieved.

Description

METHOD AND APPARATUS TO CREATE UNIFORM MIXING IN CONNECTION WITH A HYDROMETALLURGICAL PROCESS
FIELD OF THE INVENTION
The invention relates to a method and apparatus, enabling the mixing of one or several solutions in a hydrometallurgical process in a reactor to bring about the desired crystallisation, precipitation or suspension in solvent extraction. The apparatus consists of a reactor and a multi-part helical rotor mixer placed in it, in the helical rotors of which there are helical bars rotating around the shaft and supported to it.
BACKGROUND OF THE INVENTION
Non-homogenous mixing is a problem for many hydrometallurgical unit processes. In conventional solutions a blade or turbine type mixer often rotates in a volume in which the primary mixing zone is at most around 3 % of the total volume of the reactor that is used. This means that the shaft power produced by the mixer is directed very strongly on the immediate vicinity of the mixer. As a consequence, the volume-specific mixing intensity around the shaft is several tens of kilowatts per cubic metre, but falls dramatically going towards the edges of the reactor.
A spiral mixer has been developed for providing homogenous mixing in a reactor when two liquids that are insoluble in each other or a liquid and a solid are mixed together, which is described for instance in US patent publications 5,185,081 , 5,248,485 and 5,182,087. The diameter of the mixer in the apparatuses described is around 0.7 times the diameter of the reactor. However, for instance in solvent extraction, when treating solutions with a low interface tension, the mixing intensity achieved with this kind of mixer also may be too high.
When solids precipitation or salt crystallisation is carried out using a mixer, in which the mixing intensity is high, very fine precipitates or very small crystals are formed. A fine precipitate or crystal size does not create a base for further growth of the precipitate or crystal, and instead the product may become problematic due to its fineness. A high mixing intensity may also bring about mechanical wear on the precipitates or crystallisations that have already formed, resulting in the crystals being ground fine again.
PURPOSE OF THE INVENTION
The purpose of the method and apparatus accordant with the invention is to achieve a more homogenous mixing than earlier in conjunction with various hydrometallurgical unit processes such as during precipitation or crystallisation or in the mixing section of solvent extraction. The purpose of the invention is to reduce the total power used in various unit processes while nevertheless achieving a more homogenous mixing than previously in the reactor space used. When mixing is uniform throughout the entire reactor space, neither localised peak power points nor almost dead spots will be formed.
SUMMARY OF THE INVENTION
The invention relates to a method for mixing one or several solutions in a reactor in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction. Mixing with a vertical circulation flow is formed in the reactor by means of a multi-part mixer, so that the primary mixing zone is over 70 % of the effective volume of the reactor in order to achieve the homogenous, low-intensity mixing needed for precipitation, crystallisation and/or the mixing stage of solvent extraction.
According to one preferred embodiment of the invention, the primary mixing zone is over 80 % of the effective volume of the reactor. It is typical of the method accordant with the invention that uniform mixing is achieved in the reactor using a helical rotor mixer consisting of at least three helical rotors. In accordance with the method described in the invention, the primary mixing zone consists of the area remaining on the inside of the helix rotor as well as an area about the size of the cross-sectional area of the helix rotor outside the helix rotor and the height of the primary mixing zone in terms of elevation is at least the same as the height of the helix rotor.
It is typical of the method accordant with the invention that the primary mixing zones of the helix rotors merge with each other outside the helix rotors.
According to one embodiment of the invention, a flocculant is used as an agent in precipitation and/or crystallisation to flocculate the solid.
The invention also relates to an apparatus for mixing one or several solutions in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction. The apparatus comprises a reactor, which consists of a base and a cylindrical sidewall rising upwards from the base, as well as a mixer placed in the reactor. The mixer is a multi-part helix rotor mixer, which is adapted to provide homogenous mixing with a vertical circulation flow, creating a low mixing intensity, where the primary mixing zone is over 70 % of the effective volume of the reactor.
It is typical of the apparatus accordant with the invention that the helix rotor mixer comprises at least three helix rotors, which are arranged in the reactor, a power device to rotate the helix rotors, and several elongated vertical baffles projecting from the sidewall of the reactor.
It is further typical of the apparatus accordant with the invention that the helix rotor comprises a vertical rotation shaft, which is connected to a power device, and two or three helix members, which are fixed to the rotation shaft with support arms that are a radius away from the rotation shaft. In one configuration of the apparatus accordant with the invention, the helix member is circular in cross-section.
In another configuration of the apparatus, the helix member is oval in cross- section.
According to one configuration of the apparatus, the baffles are at an angle of 5 - 15 degrees to the radius of the reactor. The baffles are preferably placed in the vicinity of each helix rotor, downstream of its rotation direction. According to one configuration of the apparatus, when the number of helix rotors is three, their diameter is at least 0.33 times the diameter of the reactor.
According to another configuration of the apparatus, when the number of helix rotors is five, their diameter is at least 0.23 times the diameter of the reactor, so that one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor.
According to a third configuration of the apparatus, when the number of helix rotors is five, one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor, so that the diameter of the central helix rotor is greater than that of the rotors surrounding it.
It is typical of the apparatus accordant with the invention that the rotation shafts of the helix rotors are arranged radially in relation to the vertical central shaft of the reactor. According to one configuration of the apparatus accordant with the invention, all the helix rotors rotate in the same direction and the rotation direction of the helix members around the shaft is the same as the rotation direction of the helix rotor.
According to another configuration of the apparatus accordant with the invention, all the helix rotors rotate in the same direction and the rotation direction of the helix members around the shaft differs from the rotation direction of the helix rotor.
According to a third configuration of the apparatus accordant with the invention, the central helix rotor rotates in a different direction from the helix rotors surrounding it.
LIST OF DRAWINGS
Figure 1 presents a cross-section of one configuration of a helix rotor mixer accordant with the invention,
Figure 2 presents the profile II - II of the mixer in Figure 1 ,
Figure 3 presents the corresponding profile to Figure 2 of another helix rotor mixer configuration.
DETAILED DESCRIPTION OF THE INVENTION
Homogenous mixing with low mixing intensity in accordance with the invention that nevertheless extends across the reactor volume is achieved by means of a helix rotor mixer, which consists of at least three separate helix rotors. The mixer is placed in a reactor that is generally an upright cylinder in shape. A solution to be crystallised, a liquid containing solids, or two liquids insoluble in each other are mixed in the reactor to bring about crystallisation, precipitation or a suspension in solvent extraction. The primary mixing zone of the helix rotor mixer covers over 70 %, preferably over 80 %, of the effective volume of the reactor. Effective volume means the volume in the reactor between the bottom of the reactor and the surface of the liquid. In the case of helix rotors, the primary mixing zone consists of the area remaining within the helix rotor plus an area outside it about the size of the cross- sectional area of the helix rotor. In terms of elevation the height of the primary mixing zone is at least the same as the height of the helix rotor. Clearly, mixing also occurs outside the primary mixing zone even though the mixing intensity is lower.
The individual helix rotors of the helix rotor mixer are grouped so that their primary mixing zones merge with each other outside the helix rotors. When the helix rotor is up-pumping, it means that in this case a flow pattern is formed in which the direction of the flow within the rotor is downward and outside the rotor it is upward. The flows that come from the inside of the helix rotors turn obliquely upwards outside the helix rotors and interact with each other so that they merge with each other in the space between the helix rotors. The operating speed of the helix rotors is adjusted to be such that the formation of turbulence is prevented in the space between the helix rotors, but at the same time the desired effects are brought about by laminar mixing. When the mixing power is divided in this way to be uniform throughout the reactor, we can state that this arrangement reduces the overall energy consumption used in mixing. With this arrangement locally occurring powerful mixing forces can also be avoided and low-intensity mixing can be directed on the entire cross-section of the reactor.
One apparatus accordant with the invention, consisting of a reactor and a mixer with three separate helix rotors, is described in more detail in Figures 1 and 2. The figures show one configuration as an example, where helix rotor mixer 1 comprises three double helix rotors 7. The helix rotor mixer 1 consists of reactor 3, whose interior 4 is bounded laterally by cylindrical sidewall 5 and beneath by base 6. The double helix rotors 7 are arranged in interior 4 a radius away from the central shaft of the reactor in a triangular formation, as shown in Figure 2. Each helix rotor 7 is rotated by a power device 8. Several elongated vertical baffles 9 protrude from sidewall 5 of reactor 3. Each helix rotor 7 comprises a vertical rotating shaft 10, which is connected to a power device 8, and two identical helical tubes 11 , which are circular in cross-section and are attached to rotation shaft 10 by support arms 12. The helical tubes are symmetrically opposite each other at a distance of one radius from the shaft. The solution or solutions to be treated can be introduced into the reactor at desired points and the result of the generated reactions removed from desired points of the reactor (not shown in detail in the drawing). In the solution accordant with Figure 1 the diameter of the helix rotors is at least 0.33 times the diameter of the reactor and preferably around 0.35 times the diameter of the reactor. All the helix rotors preferably rotate in the same direction either up-pumping or down-pumping, and in this case the direction that the helical tubes rotate around the shaft is also the same as the rotation direction. Therefore the helix rotors rotate either clockwise or anticlockwise. In most cases it is more advantageous to use a up-pumping mixing direction, so that outside the helix rotors a strong upward zone is generated at each point downstream of the baffles. The upward zones merge with each other in the manner described above and intensify mixing. The upward zones can be further intensified by placing the baffles closer to the helix rotors.
It is advantageous to place the baffles 9 at a distance that is 0.04 - 0.08 times the diameter of the reactor from the sidewall of the reactor and their width is preferably 0.1 - 0.13 times the diameter of the reactor. It is typical of the baffles accordant with the invention that instead of placing them radially, they are at an angle of 5 - 15 degrees from the radius. The baffles are placed in the vicinity and downstream of each helix rotor, as shown in Figure 2. In this way an intensifying effect is attained on the homogenous mixing across the entire reactor.
By means of the three helix rotors and the three baffles described above, an arrangement is obtained providing mixing with a vertical circulation flow, whereby the primary mixing zone is over 80 % of the effective volume of the reactor. The primary mixing zone of each helix rotor is shown by a dashed line in Figure 2. This brings about the homogenous low-intensity mixing required for precipitation, crystallisation and/or the mixing stage of solvent extraction. Distribution can be affected by means of the size and location of the mixer and by the size, location and alignment of the baffles. When the mixing intensity is made fairly uniform throughout the entire reactor space in this way, the motor power used for mixing can be reduced. Depending on the mixing requirement, the mixing intensity can be adjusted for example to the range of 0.05 - 1.5 kW/m3. The advantage of the arrangement accordant with the invention is that localised strong primary mixing is no longer required thanks to the homogenous mixing that covers the whole reactor area.
Figure 3 is an illustration of a further mixer accordant with the invention, in which there are five helix rotors 7. One of the helix rotors is situated in the centre of the reactor and the four others symmetrically around the central helix rotor on the circumference of the reactor. The diameter of the helix rotors is at least 0.23, preferably 0.25 - 0.3 times the diameter of the reactor. There are four baffles 9 in number and they are located in the vicinity of the helix rotors on the circumference on the same principle as described in conjunction with Figures 1 and 2. The arrangement accordant with Figure 3 can achieve a situation where as much as 85 % of the mixing in the reactor space is primary mixing. The structural configuration accordant with Figure 3 can be changed further so that the diameter of the helix rotor situated in the central part of the reactor is greater than the diameter of the helix rotors located on the circumference of the reactor. In this case the rotation direction of all the helix rotors can be selected to be the same or the rotation direction of the centrally placed helix rotor can be selected to differ from the rotation direction of the helix rotors located on the circumference. The examples above have referred to a helix rotor with two helical members only as an example. Depending on the requirements of the application the helix rotor may have two or three helical members. Three helical members together in the rotor makes the rotor more solid structurally and achieves a more even distribution of mixing power compared with two helical members. As for the helical member, it may be some other shape than round in cross section. A round bar may also be flattened, so that the profile of the helical member is oval in shape. As stated above, the properties of the solid to be precipitated or crystallised can be improved with homogenous mixing. Growth in particle size during solid precipitation and crystallisation can be controlled better than in apparatus where there is a powerful, narrow primary mixing. In addition to the equipment selection, a flocculant can also be used to aid the flocculation of solids. An example of this is the fact that using a helix rotor mixer accordant with the invention consisting of three helix rotors with the aid of a flocculating agent in the feedwell of the thickener caused the solids content of the thickener overflow to fall from a value of 50 mg/L to 15 mg/L. The method and apparatus accordant with the invention are particularly advantageous when the diameter of the reactor is large, in the region of tens of metres.
The invention is not restricted to the example configurations presented above; many modifications are possible while remaining within the framework of the concept of the invention as specified in the claims.

Claims

PATENT CLAIMS
1. A method for mixing one or several solutions in a reactor (3) in conjunction with a hydrometallurgical process, such as precipitation, crystallisation or forming a suspension in solvent extraction, characterised in that mixing with a vertical circulation flow is formed in the reactor b y means of a multi-part mixer (1 ), whereby the primary mixing zone is over 70 % of the effective volume of the reactor in order to achieve the uniform mixing of low intensity required for precipitation, crystallisation and/or the mixing stage of solvent extraction.
2. A method according to claim 1 , characterised in that the primary mixing zone is over 80 % of the effective volume of the reactor. 3. A method according to claim 1 , characterised in that uniform mixing is achieved in the reactor using a helix rotor mixer consisting of at least three helix rotors.
A method according to claim 1 , characterised in that the primary mixing zone comprises the area remaining inside the helix rotor and an area about the size of the cross-sectional area of the helix rotor outside the helix rotor and, in terms of elevation, the height of the primary mixing zone is at least the same as the height of the helix rotor. 5. A method according to claim 1 or 4, characterised in that the primary mixing zones of the helix rotors merge with each other outside the helix rotors.
6. A method according to claim 1 , characterised in that a flocculant is used to aid the flocculation of solids in precipitation and/or crystallisation.
7. An apparatus for mixing one or several solutions in conjunction with a hydrometallurgical process such as precipitation, crystallisation or forming a suspension in solvent extraction, whereby the apparatus comprises a reactor (3), which consists of a base (6) and a cylindrical sidewall (5) rising upward from the base, and a mixer (1) located in the reactor, characterised in that the mixer (1) is a multi-part helix rotor mixer, which is adapted to provide mixing with a vertical circulation flow forming a homogenous, low mixing intensity, in which the primary mixing zone is over 70 % of the effective volume of the reactor.
An apparatus according to claim 7, characterised in that the helix rotor mixer (1) comprises at least three helix rotors (7), which are arranged in a reactor, a power device (8) to make the helix rotors (7) rotate, and several elongated vertical baffles (9) protruding from the sidewall of the reactor.
An apparatus according to claim 8, characterised in that the helix rotor (7) comprises a vertical rotation shaft (10), which is connected to a power device (8), and two or three helical members (11), which are fixed to the rotation shaft (10) by support arms (12) at a distance of a radius from the rotation shaft. 10. An apparatus according to claim 9, characterised in that the helical member (11) is circular in cross section.
11. An apparatus according to claim 9, characterised in that the helical member (11) is oval in cross section.
12. An apparatus according to claim 8, characterised in that the baffles (9) are at an angle of 5 - 15 degrees to the radius of the reactor.
13. An apparatus according to claim 8, characterised in that the baffles (9) are located in the vicinity of each helix rotor (7), downstream of its rotation direction.
14. An apparatus according to claim 8 , characterised in that when the number of helix rotors (7) is three, their diameter is at least 0.33 times the reactor diameter. 15. An apparatus according to claim 8 , characterised in that when the number of helix rotors (7) is five, and their diameter is at least 0.23 times that of the reactor diameter, one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor. 16. An apparatus according to claim 8 , characterised in that when the number of helix rotors (7) is five, one helix rotor is located in the centre of the reactor and the four others symmetrically around the central helix rotor, so that the diameter of the central helix rotor is greater than that of the rotors surrounding it.
17. An apparatus according to claim 8, characterised in that the rotation shafts (10) of the helix rotors (7) are arranged radially in relation to the vertical central shaft of the reactor (3). 18. An apparatus according to claim 9, characterised in that all the helix rotors (7) rotate in the same direction and the direction of rotation of the helical members (11) around the shaft (10) is the same as the rotation direction of the helix rotor. 19. An apparatus according to claim 9, characterised in that all the helix rotors (7) rotate in the same direction and the rotation direction of the helical members (11 ) around the shaft (10) differs from the rotation direction of the helix rotor.
20. An apparatus according to claim 15 or 16, characterised in that central helix rotor (7) rotates in a different direction to the helix rotors surrounding it.
EP10835537.1A 2009-12-08 2010-12-08 METHOD AND APPARATUS FOR CREATING A UNIFORM MIXTURE IN RELATION TO A HYDROMETALLURGICAL PROCESS Withdrawn EP2509709A4 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20096296A FI123597B (en) 2009-12-08 2009-12-08 Method and apparatus for separating solid particles from sludge and using the method and / or apparatus
PCT/FI2010/000074 WO2011070219A1 (en) 2009-12-08 2010-12-08 Method and apparatus to create uniform mixing in connection with a hydrometalurgical process

Publications (2)

Publication Number Publication Date
EP2509709A1 true EP2509709A1 (en) 2012-10-17
EP2509709A4 EP2509709A4 (en) 2016-01-06

Family

ID=41462762

Family Applications (1)

Application Number Title Priority Date Filing Date
EP10835537.1A Withdrawn EP2509709A4 (en) 2009-12-08 2010-12-08 METHOD AND APPARATUS FOR CREATING A UNIFORM MIXTURE IN RELATION TO A HYDROMETALLURGICAL PROCESS

Country Status (11)

Country Link
EP (1) EP2509709A4 (en)
CN (1) CN102665887B (en)
AU (1) AU2010329807A1 (en)
BR (1) BR112012013894A2 (en)
CA (1) CA2780852A1 (en)
CL (1) CL2012001477A1 (en)
EA (1) EA022724B1 (en)
FI (2) FI123597B (en)
PE (1) PE20130300A1 (en)
WO (2) WO2011070218A1 (en)
ZA (1) ZA201203911B (en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA3159264A1 (en) * 2012-06-21 2013-12-21 Suncor Energy Inc. Process for treating tailings using low sand-to-fines ratio, flocculation and dewatering
CN103936042A (en) * 2013-01-22 2014-07-23 贵阳铝镁设计研究院有限公司 Three-shaft stirring decomposing tank
CA2823459C (en) 2013-08-09 2015-06-23 Imperial Oil Resources Limited Method of using a silicate-containing stream from a hydrocarbon operation or from a geothermal source to treat fluid tailings by chemically-induced micro-agglomeration
BR112016024409A2 (en) 2014-04-30 2017-08-15 Dow Global Technologies Llc polymeric flocculants for treating aqueous mineral suspensions
BR112016024265A2 (en) 2014-04-30 2017-08-15 Dow Global Technologies Llc treating aqueous mineral suspensions with a polymeric flocculant
US20170216791A1 (en) 2014-07-31 2017-08-03 Dow Global Technologies Llc In-line dynamic mixing apparatus for flocculating and dewatering oil sands fine tailings
CN104226147B (en) * 2014-10-15 2016-08-17 浙江辰鸿纺织品科技有限公司 A kind of for window cloth slurry high efficiency dispersion mixing arrangement
WO2017034790A1 (en) 2015-08-25 2017-03-02 Dow Global Technologies Llc Flocculation of high-solids mineral slurries
AR108480A1 (en) 2016-05-27 2018-08-22 Dow Global Technologies Llc METHOD OF TREATMENT OF MINERAL SUSPENSIONS WITH HIGH CONTENT OF SOLIDS WITH POLYMER FLOCULANTS
US20190233310A1 (en) 2016-07-25 2019-08-01 Dow Global Technologies Llc Acoustic mixing for flocculant addition to mineral suspensions
CA3038070A1 (en) 2016-09-23 2018-03-29 Dow Global Technologies Llc Process for tailings remediation
US20210371316A1 (en) 2016-09-27 2021-12-02 Dow Global Technologies Llc Process for dewatering an aqueous process stream
CN106861501A (en) * 2017-03-20 2017-06-20 无锡科技职业学院 A kind of high-shear emulsifying dissolves mixing kettle
EP3680007B1 (en) * 2018-03-05 2023-06-07 Nippon Sosey Kogyo Co., Ltd. Rotary mixer in two-liquid mixture injection machine
CN109529703A (en) * 2018-11-28 2019-03-29 河南易成新能源股份有限公司 Graphite product ingredient mixing arrangement
CN112456672A (en) * 2019-09-09 2021-03-09 国家能源投资集团有限责任公司 Mine water treatment method and system
CA3182898A1 (en) * 2020-04-20 2021-10-28 Metso Outotec Finland Oy Mixing arrangement, mixer settler unit and use
CN119080378A (en) * 2024-11-05 2024-12-06 胜利油田万和石油工程技术有限责任公司 Oil drilling mud processing system

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR615110A (en) * 1926-04-26 1926-12-30 Mixer
NL52125C (en) * 1939-03-31 1942-03-16
DE1225951B (en) * 1961-08-10 1966-09-29 Wilhelm Heinrich Schmidt Mixing device
US4198376A (en) * 1974-02-14 1980-04-15 Rhone-Progil Vertical autoclave for bulk polymerization of vinyl chloride based polymers and copolymers
US5248485A (en) * 1990-04-04 1993-09-28 Outokumpu Oy Method for mixing liquid, solids and gas and for simultaneously separating gas or gas and solids from the liquid
CN2158301Y (en) * 1993-03-26 1994-03-09 郭洪臣 Double-shaft helice mixer
DE19901267B4 (en) * 1999-01-15 2006-08-10 Löhr, Anke, Dr. Mixing and treatment device
FI114783B (en) * 2001-06-25 2004-12-31 Outokumpu Oy Sludge sedimentation method and apparatus
FI123662B (en) * 2006-02-17 2013-08-30 Outotec Oyj Process and mixing plant for mixing gas in sludge in a closed reactor
CA2673982A1 (en) * 2008-07-28 2010-01-28 Hunton Energy Holdings, LLC Basic filtration of bitumen fines

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2011070219A1 *

Also Published As

Publication number Publication date
FI20096296A0 (en) 2009-12-08
WO2011070219A1 (en) 2011-06-16
FI124092B (en) 2014-03-14
FI20100318A0 (en) 2010-09-16
CN102665887A (en) 2012-09-12
ZA201203911B (en) 2013-04-24
WO2011070218A1 (en) 2011-06-16
CN102665887B (en) 2015-06-24
WO2011070219A8 (en) 2011-11-17
EA201290405A1 (en) 2013-01-30
AU2010329807A8 (en) 2012-07-19
FI123597B (en) 2013-07-31
PE20130300A1 (en) 2013-03-22
FI20100318L (en) 2011-06-09
CA2780852A1 (en) 2011-06-16
FI20096296L (en) 2011-06-09
EA022724B1 (en) 2016-02-29
BR112012013894A2 (en) 2016-05-03
EP2509709A4 (en) 2016-01-06
AU2010329807A1 (en) 2012-06-21
CL2012001477A1 (en) 2012-11-16

Similar Documents

Publication Publication Date Title
EP2509709A1 (en) Method and apparatus to create uniform mixing in connection with a hydrometalurgical process
US10369535B2 (en) Rapid stirring machine
FI121621B (en) Mixer for mixing sludge in a metallurgical process
AU2009295261B2 (en) A separation device with dual drives and a method of reducing donutting in a separation device
CN104411392B (en) Mixer
DE69811207T2 (en) LIQUID GAS VORTEX MIXER
US20090301948A1 (en) Method and apparatus for treating wastewater
CN102068955A (en) Flocculation reactor with special-shaped spoiler
US10865459B2 (en) Reactor for gas-liquid mass transfer
JPH07108371B2 (en) Method for generating double loop flow and corresponding device
US7275704B2 (en) Compound dispersing method and apparatus
JPWO2011040620A1 (en) Processing equipment
JPH0321338A (en) Apparatus for mixing viscous material
CN107456905A (en) A kind of filter cake beating apparatus and method and its application
US20140036618A1 (en) Device for bringing a liquid species into contact with a growing particulate solid species
RU2519113C2 (en) Method of control over disturbance of mesh-texture sludge
EP3603810A1 (en) Pressure vessel with magnetic disc for spinning
US12053749B2 (en) Mixing apparatus and method of operation
ES2388736T3 (en) Mixing device for divided solid waste
US20150299821A1 (en) Mixing method and device for solvent extraction, especially in hydrometallurgical processes
CN117919988A (en) Impeller for stirring
CN203155121U (en) Dispersion machine
EA020355B1 (en) An open pressurised agitated reactor and a method for mixing gas and slurry with each other
CN214916032U (en) Reaction kettle stirring device
CN109289579A (en) Double-layer convection formula agitating paddle

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20120628

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: OUTOTEC OYJ

RA4 Supplementary search report drawn up and despatched (corrected)

Effective date: 20151204

RIC1 Information provided on ipc code assigned before grant

Ipc: C02F 11/14 20060101ALI20151130BHEP

Ipc: B01F 3/12 20060101AFI20151130BHEP

Ipc: C02F 1/34 20060101ALI20151130BHEP

Ipc: B01F 7/16 20060101ALI20151130BHEP

Ipc: B01D 21/28 20060101ALI20151130BHEP

Ipc: C02F 1/52 20060101ALI20151130BHEP

Ipc: B01D 21/08 20060101ALI20151130BHEP

Ipc: B01F 7/24 20060101ALI20151130BHEP

Ipc: B01D 21/01 20060101ALI20151130BHEP

Ipc: C10G 1/00 20060101ALI20151130BHEP

Ipc: B01F 7/00 20060101ALI20151130BHEP

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20160601