RU2286212C1 - Method of control over the floatation process - Google Patents

Abstract

FIELD: mining industry; methods of control over the technological processes.

SUBSTANCE: the invention is pertaining to the control over the technological processes and may be used at automated control over operations of the ore mills, in particular, at the floatation separation of the converter matte. The technical result of the invention is the increased degree of separation of the metals contained in the feedstock. The method includes measurement the contents of metals in the feeding of the rough floatation and in the intermediate products (IP) of the floatation, sent to the additional grinding, measurement of the volumetric consumptions and the mass shares of the solid pulp with the calculation of the mass consumptions of the metals at the inlet into the main flotation and in the IP of the floatation with the subsequent determination of the difference of the extractions the depressed and floated metals (FM) as the chambered product of the main rough flotation. Using variation of the consumption of reactants, the degrees of aeration and the levels of the pulp in the chambers of flotation machines it is possible reach the greatest difference of extractions of the depressed product IP in the chambered product of the rough flotation. Then the mass consumption of FM into IP from the cleaner flotation sent to the regrinding is kept of no more than the permissible limit by changing of the consumption of the gatherer in the cleaner flotation. At that in the case of exceeding the permissible limit of the mass consumption of FM, the consumption of the gatherer is reduced, and in the case of reduction of the mass consumption of FM below the permissible limit, the consumption of the gatherer is increased.

EFFECT: the invention ensures the increased degree of extraction of the metals contained in the feedstock.

5 cl, 2 ex, 1 dwg

Description

The present invention relates to process control and can be used in the automated control of flotation concentration plants, in particular in the flotation separation of copper-Nickel matte.

A known method of flotation (AS No. 107956, 03 D 1/02, publ. 1957), in which the ore is divided into several parts separately subjected to flotation, with each part of the ore with the exception of one subjected to flotation together with the concentrate obtained by flotation of one of the other parts. The disadvantage of this method is that a significant part of the circulating flows contains substandard fractions, which are impractical to supply to the input of the flotation process, since this increases circulation and reduces the flotation time. Substandard components of the circulation flows, it is advisable to isolate and regrind to condition.

There is a method of flotation concentration of minerals (A.Z. Rulnova, A.E. Golubova, I.M.Sonina. V.L. Zabelin. Automation of processing plants abroad. Overview information of the Central Research Institute is in bloom of economics and information. - M .: Issue 3, 1985, p.37), according to which in copper flotation the main control criterion is to maintain a given upper limit of the copper content in the tails. The only measurable flow in flotation is the consumption of copper intermediate products, which, in principle, regulates the circulating load. When the flow of intermediate products increases, the setting of the copper content in the concentrate of the first purification decreases. This increases the amount of concentrate in the first purification and accordingly reduces the flow of intermediate products. The disadvantage of this method is that the circulating products in some situations are not processed, but sent to the head of the flotation process. There is also no control of the main flotation in order to prepare rough concentrates for separation in the control and cleaning flotations in order to better separate the components.

The closest adopted as a prototype is a method for controlling the flotation-flotation concentration cycle (AS No. 1546161, 03 D 1/00, publ. 1990), based on the measurement of metal content and solid consumption in flotation products and changes in the number of products flotation directed to grinding, while taking into account the change in the content of splices of useful minerals with minerals of waste rock, measure the metal content and solid consumption in the intermediate flotation products and with a decrease in the metal content and an increase in the consumption of t erdogo intermediates directed to additional milling, while increasing the content of metal intermediates sent directly to the main power flotation. In common with the prototype and the claimed method is that the circulation products in the prototype in some cases are sent for regrinding.

The disadvantage of this method is that with an increase in the metal content, the entire circulation stream is directed to the main flotation supply. Such actions are justified if the task is to separate metals from waste rock. In the case of separation of raw materials in which there is no gangue, such as Feinstein, such actions will reduce the degree of separation of metals contained in Feinstein and increase the amount of polluting metals in concentrates.

The second disadvantage of the prototype is the low level of technical support of the method in terms of obtaining such important information as the mass flow of metals and metal extraction from the operations of the flotation process, which does not allow to increase the accuracy of decision-making when managing technological operations of the flotation process.

The third disadvantage is that the hydroclone of the classification of the intermediate product cannot work efficiently with a variable input stream, in such conditions the hydrocyclone cannot provide the specified subtlety of cutoff of the finished class.

The objective of the invention is to provide the lowest possible content of polluting metals in the resulting concentrates under conditions of variable dissemination of the composition of the feedstock.

As a result of solving this problem, the following technical result was obtained: the degree of disclosure of splices of the feedstock was increased and the degree of separation of metals contained in the feedstock was increased.

The essence of the invention lies in the fact that during flotation separation of metals contained in the feedstock, the work of redistribution of flotation is successively optimized, while at the entrance to the main flotation and in the intermediate flotation products, the metal contents, volumetric flows and weight fractions of solid pulp are measured, then the mass pulp is calculated metal consumption at the entrance to the main flotation and in the intermediate flotation products, after which the difference between the extracts of the depressed and floated metals in the chamber product is determined Noah flotation by the equation:

? E = 100 · (G _dk / G -G _{DWR fc} / G _fvh)

where ΔЕ is the difference between the extracts of the depressed and floated metals in the chamber product of the main flotation,%;

G _dc - mass flow rate of the depressed metal in the chamber product of the main flotation, t / h;

G _dvh - mass flow rate of the depressed metal at the entrance to the main flotation, t / h;

G _fc - mass flow rate of the floated metal in the chamber product of the main flotation, t / h;

G _fvh - mass flow rate of the floated metal at the entrance to the main flotation, t / h,

then, the greatest difference in the extracts of the depressed and floated metals into the chamber product of the main flotation is achieved by changing the consumption of reagents for the main flotation, the degree of aeration, and the pulp levels in the chambers of the flotation machines.

After reaching the greatest difference in the extracts of the depressed and floated metals into the chamber product of the main flotation, the degree of aeration and pulp levels do not change further.

The optimal value of the extraction of flotation metal into the chamber product of the main flotation is supported only by a change in the consumption of reagents.

The quality of the final concentrates is significantly affected by intergrowths of metal compounds, the amount of which depends on the grain size of the feedstock (impregnation).

The point characterizing, ultimately, the entire course of the flotation separation of metals, is the output of the intermediate product from the rough flotation containing the floated metal.

The flow rate of the metal to be flotated in the intermediate product from the roughing flotation, sent for regrinding, is maintained no higher than the permissible limit by changing the collector flow rate to the cleaning flotation, in this case, if the mass flow rate of the flotation metal exceeds the allowable limit, the collector flow rate is reduced, and if the mass flow rate of the floating metal is reduced below allowable flow rate collector increase.

At first glance, such actions look illogical, since with an increase in the consumption of the intermediate product by a decrease in the consumption of the collector in the cleaning operation, the consumption of the intermediate product not only does not decrease, but increases even more. However, in the future, after additional grinding of the splices that have passed into the intermediate product, the degree of disclosure of metal compounds will increase, and when minerals pass through the screening operation again, the floated metal contained in them will pass into the foam product (technological concentrate) and the consumption of the intermediate product containing splices will decrease.

To determine the working values of the extracts of the depressed and floated metals in the chamber product of the main flotation, the last three calculated values of the extracts of metals by the moving average method on the time interval, which is determined by the equation, are used:

Δτ = V _ff / Q _rp ,

where Δτ is the time interval for calculating the average extraction, h;

V _ff - the front of the main flotation, m ³ ;

Q _RP - volumetric flow rate of the main flotation, m ³ / h

To maintain the quality of the concentrate with the depressed metal passing through the control flotation, the upper permissible limit for the extraction of the floated metal into the chamber product of the main flotation is set, which is taken to be 20% in case of separation of the matte.

To prevent deterioration in the quality of concentrates by timely sending to the regrinding an increasing flow of splices in the intermediate product from roughing flotation, which is associated either with the enlargement of particles after grinding, or with a change in the impregnation of the feedstock, the ratio of the mass flow rate of the floated metal in the intermediate from the roughing flotation to the mass flow rate of the feedstock support in the range from 0.14 to 0.15.

To ensure the stability of all operations of the flotation process, such important technological quantities as the flow rate and pulp density at the entrance to the main flotation are kept stable.

The drawing shows a block diagram of the implementation of the proposed method. The proposed method is as follows. After grinding, the feedstock in the form of pulp 14 is mixed with the pulp stream from regrinding, and the resulting pulp mixture is fed to the inlet of the control classification hydrocyclone 13. The combined discharge of the hydrocyclone 13 and the by-product hydrocyclone 11 is fed to the main flotation inlet. The foam product of the main flotation enters the cleanup flotation, and the chamber product goes to the control flotation. The volumetric flow rate of the main flotation supply is measured by flow meters 1 and 7. The content of the flotated and depressed components and the weight fraction of solid in the feed of the main flotation, the chamber product of the main flotation, and in the intermediate product from the purification are measured by a COURIER-30XP automatic X-ray spectral analyzer (5) with sampling lines, respectively, 2 , 4 and 6. The volumetric flow rate of the total intermediate product is measured by the flow meter 12. The volumetric flow rate of the intermediate product from the cleaning operation is measured by the flow meter 15. The flow rate of the collector (xanto The Senate) to the main flotation, flotation and the flotation is supported by a control feeders respectively 3, 8 and 10. The consumption of alkali in the flotation support 9 dispenser.

Information from the sensors enters the information and computer complex and is displayed on the workstations of the operator-technologist. Depending on the change in the values of the parameters of the technological quantities, the operator changes the tasks for the dispensers for the consumption of reagents.

Example I

Initial mode:

The performance of the crushed Feinstein of the Feinstein grinding section is 22 t / h.

The main flotation.

The volumetric flow rate of the main flotation feed pulp is 110 m ³ / h;

The weight fraction of solid in the feed pulp of the main flotation is 30.01%;

Cu content in the solid phase of the pulp of the main flotation

- 31.35%;

The Ni content in the solid phase of the pulp of the main flotation is 39.14%;

Mass consumption of Cu in the feed pulp of the main flotation - 13.82 t / h;

The mass flow rate of Ni in the feed pulp of the main flotation is 17.25 t / h;

The flow rate of a solution of potassium butyl xanthate in the main flotation is 0.75 l / min (45 l / h);

The specific consumption of a solution of potassium butyl xanthate in the main flotation is 3.25 l / t Cu.

Output indicators of the main flotation.

The volumetric flow rate of the pulp of the chamber product of the main flotation is 100.8 m ³ / h;

The weight fraction of the solid in the pulp of the chamber product of the main flotation is 15.54%;

The Cu content in the solid phase of the pulp of the chamber product of the main flotation is 14.31%;

The Ni content in the solid phase of the pulp of the chamber product of the main flotation is 63.85%;

Mass consumption of Cu in the pulp of the chamber product of the main flotation is 2.6 t / h;

The mass flow rate of Ni in the pulp of the chamber product of the main flotation is 11.61 t / h;

Extraction of Cu in the chamber product of the main flotation in the time interval of the main flotation (18 min) - 18.81%;

Extraction of Cu in the foam product of the main flotation at the time interval of the main flotation (18 min) - 81.19%;

Extraction of Ni in the chamber product of the main flotation at the time interval of the main flotation (18 min) - 67.34%;

The extraction of Ni in the foam product of the main flotation in the time interval of the main flotation (18 min) is 32.66%.

Disturbance:

The moving average extraction of Cu in the solid phase of the pulp of the chamber product of the main flotation increased to 21% due to the enlargement of the fineness of the grinding and an increase in the content of splices in the pulp of the feed of the main flotation.

The purpose of the control action:

To increase the collector's effect on large fractions of pulp and intergrowths of the solid phase of the pulp of the main flotation in order to remove them into the foam product of the main flotation and then clean them up to the conditioned (second cleanup) and substandard (to regrind) components.

Control action:

Set the task to system 3 (Fig. 1) of stabilizing the flow rate of a solution of potassium butyl xanthate in the main flotation up to the level: (45 + (((20-18.81) / 18.81) · 45)) / 60 = 0.8 l / min

System response:

An increase in the current yield value of the foam product of the main flotation began, which required the correction of the reagent regime for clean flotation.

The consumption of the mid-product of the flotation process increased in proportion to the increase in the content of substandard fractions in the solid phase of the pulp of the foam product of the main flotation.

The extraction of Cu into the chamber product of the main flotation returned to the level of 17.8% after a time interval of 18 minutes.

Example II

Initial mode:

The performance of the crushed Feinstein of the Feinstein grinding section is 22 t / h.

Recycling flotation.

The volumetric flow rate of industrial product pulp from rough flotation is 38.24 m ³ / h;

The weight fraction of the solid product in the pulp of the intermediate product of flotation flotation is 15.25%;

The Cu content in the solid phase of the pulp by-product flotation flotation - 40.09%;

Mass flow rate of Cu in the pulp of the by-product flotation flotation - 2,708 t / h;

The flow rate of a solution of potassium butyl xanthate in the first recycle flotation is 0.24 l / min, (14.4 l / h).

Disturbance:

The mass flow rate of Cu in the pulp of the intermediate product from rough flotation increased to - 3.2 t / h;

The purpose of the control action:

To reduce the impact of the collector on large fractions of pulp and intergrowths of the solid phase of the pulp in the first recycle flotation in order to bring them into the intermediate product and further regrind large fractions and open the intergrowths.

Control action 1:

Set the task to system 8 (Figure 1) of stabilizing the flow rate of a solution of potassium butyl xanthate in the first purge flotation up to the level: (14.4 - (((3.2-2.708) / 2.788) · 14.4)) / 60 = 0 , 19 l / min.

System response:

The mass flow rate of Cu in the pulp of the intermediate product from the rough flotation increased even more, up to 3.7 t / h.

The weight fraction of the solid product in the pulp of the by-product flotation increased.

The Cu content in the solid phase of the pulp of the by-product flotation flotation increased.

The volumetric flow rate of the pulp of an industrial hydrocyclone increased.

The flow of sand unloading industrial hydrocyclone increased.

The contaminant metal content in the process concentrate of flotation flotation remained unchanged.

An additional stream of coarse fractions and intergrowths, submitted for cleaning flotation, was sent for regrinding.

After a period of time equal to the main flotation time of 18 minutes, a tendency began to decrease in the mass flow of Cu in the pulp of the by-product of flotation flotation.

Control action 2:

The task of stabilizing the flow rate of a solution of potassium butyl xanthate in the first cleanup flotation at the level of 0.24 l / min (14.4 l / h) was restored.

An industrial verification of the proposed method for controlling the Feinstein separation process in comparison with the known method has shown its higher accuracy and control efficiency to ensure improved indicators of the Feinstein separation. So, when implementing the control method, the sum of the second metals in the obtained concentrates (nickel content in copper concentrate + copper in nickel) was reduced by 0.2%.

Due to the increase in the proportion of nickel in nickel concentrate, the recovery of nickel oxide in tube furnaces increased by 0.2%.

Information sources

1. A.S. No. 107956, B 03 D 1/02, Method for the flotation of ores.

2. A.Z. Rulnova, A.E. Golubova, I.M. Sonina. V.L. Zabelin. Automation of processing plants abroad. Overview of the Central Research Institute is the color of the economy and information. - M .: Issue 3, 1985.p.59.

3. A.S. No. 1546161, B 03 D 1/00. The method of controlling the grinding-reduction cycle of enrichment (prototype).

Claims (5)

1. A method of controlling the flotation process, including measuring the metal content in the intermediate flotation products and changing the amount of intermediate flotation products sent for grinding, characterized in that at the inlet of the main flotation and in the intermediate flotation products, volumetric flows and weight fractions of solid pulp are additionally measured, and at the entrance to the main flotation, the metal content is also measured, then the mass flow rates of metals at the entrance to the main flotation and in the intermediate flotation products, calculated after e this determines the difference between the extracts of the depressed and floated metals in the chamber product of the main flotation according to the equation ? E = 100 · (G _dk / G -G _{DWR fc} / G _fvh) where ΔЕ is the difference between the extracts of the depressed and floated metals in the chamber product of the main flotation,%; G _dc - mass flow rate of the depressed metal in the chamber product of the main flotation, t / h; G _dvh - mass flow rate of the depressed metal at the entrance to the main flotation, t / h; G _fc - mass flow rate of the floated metal in the chamber product of the main flotation, t / h; G _fvh - mass flow rate of the floated metal at the entrance to the main flotation, t / h, then the greatest difference between the extracts of the depressed and floated metals in the chamber product of the main flotation is achieved by changing the consumption of reagents for the main flotation, the degree of aeration and the pulp levels in the chambers of the flotation machines, after that the degree of aeration and pulp levels do not change, and the optimal value of the extraction of the floated metal into the chamber product main flotation support by changing the flow rate of the reagents, then the mass flow rate of the metal to be floated in the intermediate product from the roughing flotation sent for regrinding, it is maintained no higher than the permissible limit by changing the collector flow rate to clean flotation, in this case, if the mass flow rate of the floated metal exceeds the permissible limit, the collector flow rate is reduced, and if the mass flow rate of the floated metal falls below the permissible limit, the collector flow rate is increased. 2. The method according to claim 1, characterized in that the extraction of the depressed and floated metals in the chamber product of the main flotation is calculated as the moving average of the last three values of the metal extracts on the time interval, which is determined by the equation Δτ = V _ff / Q _rp , where Δτ is the time interval for calculating the average extraction, h; V _ff - the front of the main flotation, m ³ ; Q _RP - volumetric flow rate of the main flotation, m ³ / h 3. The method according to claim 1, characterized in that in the case of separation of the Feinstein, the upper limit of the extraction of the floated metal into the chamber product of the main flotation is taken to be 20%. 4. The method according to claim 1, characterized in that in the case of separation of the Feinstein, the ratio of the mass flow rate of the metal to be floated in the intermediate product from recycle flotation to the mass flow rate of the feedstock is maintained in the range from 0.14 to 0.15. 5. The method according to claim 1, characterized in that the main flotation process is carried out at a stable flow rate and pulp density at the entrance to the main flotation.