RU2167209C1 - Method of processing sulfide copper-zinc materials - Google Patents

Abstract

FIELD: metallurgy; processing sulfide polymetallic materials containing zinc, copper and iron. SUBSTANCE: proposed method includes autoclave oxidizing leaching of part of ground starting material under pressure of oxygen at temperature above sulfur melting point and mole ratio of H₂SO₄:Zn equal to (0.85-1.12) for obtaining zinc-containing solution and insoluble residue containing copper, zinc, iron in form of sulfides, lead and precious metals followed by direction of zinc-containing solution to next leaching stage to which part of starting material is fed; leaching at second stage is performed by autoclave oxidizing method at temperature above sulfur melting point and mole ratio of H₂SO₄:Zn equal to (0.85 - 1.12), thus obtaining solution containing at least 100 g/l of zinc and insoluble residue containing copper, zinc, iron and precious metals; insoluble residues are directed for processing by known methods. EFFECT: enhanced efficiency of processing sulfide copper-and-zinc materials at low content of zinc; increased throughput of process and improved quality of commercial product. 1 tbl, 3 ex

Description

 The invention relates to hydrometallurgy and can be used in the processing of sulfide polymetallic materials containing zinc, copper and iron.

 The problem of processing poor in zinc content (up to 18% Zn) sulfide copper-zinc materials is currently gaining great importance. These zinc-containing materials practically do not participate in the technological process, since known processing methods, as a rule, do not allow zinc solutions suitable for obtaining marketable products due to the low zinc content in them.

For example, there is a known method for processing sulfide copper-zinc polymetallic concentrates, in which the initial ground material is subjected to autoclave oxidative leaching under oxygen pressure at an elevated temperature, followed by exposure of the suspension in a non-oxidizing atmosphere at a temperature above the melting point of sulfur, and leaching is carried out until oxidation of 25- 50% copper sulfide at an initial pulp pH above 1.0 and a temperature of 160-200 ^o C (ed. St. USSR N 1788050, IPC C 22 B 3/04, publ. 15.01.93, Bull. N 2).

 The known method does not allow to efficiently process the above-mentioned copper-zinc materials with a small (up to 18%) zinc content and to obtain solutions suitable for the zinc content for the production of cathode zinc or zinc sulfate.

 The closest analogue to the claimed invention is a method for processing sulfide copper-zinc materials, including autoclave oxidative leaching of a portion of the crushed starting material under oxygen pressure at a temperature above the melting point of sulfur to obtain a zinc-containing solution and an insoluble residue containing copper, zinc, iron in the form of sulfides, lead and precious metals, the direction of the obtained zinc-containing solution to the next stage of leaching at atmospheric pressure, to the cat Rui fed part of the source material, preparation of Zn-containing solution and the insoluble residue and the zinc solution purification from admixtures (RF Patent N 2023728, IPC C 22 B 3/08, publ. 30.11.94, Bul. 22 N).

 In this case, the second leaching stage in the known method is aimed at neutralizing the free acid of the solution of the first stage with a part of the initial zinc-containing material.

 The known method also provides for the direction obtained after the first stage of the residue containing sulfur, copper, zinc, iron in the form of sulfide, lead and silver, to leach a solution of sulfuric acid at a temperature below the boiling point of the mixture at atmospheric pressure in the presence of finely dispersed oxygen with an excess of acid to obtain an excess of acid to obtain a solution containing free acid in an amount of 60-169 g / l, 2-3 g / l of ferric iron and the residue.

 The disadvantage of this method is its low efficiency in the processing of copper-zinc materials with a low (up to 18%) zinc content, since the concentration of zinc in the solution necessary for its further extraction into commercial products is not provided. In addition, the high extraction of copper (up to 50%) and iron (up to 15%) into the solution makes it practically unsuitable for both zinc production by electrolysis and zinc sulfate production.

 The invention is aimed at developing a simple and effective method for processing copper-zinc materials with a small (up to 18%) zinc content, which allows to obtain solutions with a zinc content of at least 100 g / l, suitable for subsequent production of cathode zinc or zinc sulfate.

 The technical result of the proposed method is to increase the extraction of zinc in a commodity solution while reducing the content of copper and iron impurities in the latter.

The technical result noted above is achieved by the fact that in the method for processing sulfide copper-zinc concentrates, including autoclave oxidative leaching of a portion of the crushed starting material under oxygen pressure at a temperature above the melting point of sulfur to obtain a zinc-containing solution and an insoluble residue containing copper, zinc, iron in the form sulfides, lead and precious metals, the direction of the obtained zinc-containing solution to the next stage of leaching, which serves part of the outcome th material, obtaining zinc-containing solution and the insoluble residue and the zinc solution purification from impurities autoclave oxidative leaching process in a first step carried out at a molar ratio of H ₂ SO _4: Zn, 0.85 -1.12, leaching in the second step is carried out by autoclave oxidative leaching at temperatures above the melting point of sulfur and a molar ratio of H ₂ SO ₄ : Zn equal to 0.85 - 1.12, to obtain a solution containing at least 100 g / l of zinc, and insoluble residues containing copper, iron, lead and precious metals sent for processing by known methods.

 The essence of the proposed method is as follows.

The studies showed that the two-stage treatment of sulfide copper-zinc material, in which the crushed starting material is divided into two parts, of which one is subjected to autoclave oxidative leaching under oxygen pressure at a temperature above the melting point of sulfur and the experimentally established molar ratio of H ₂ SO ₄ and Zn to obtain a zinc-containing solution, which, in turn, is sent to the autoclave oxidative leaching at a temperature above the point melting sulfur and the experimentally established molar ratio of H ₂ SO ₄ and Zn, to which the remainder of the initial ground material is fed, and processing insoluble residues, provides a significant reduction in the content of copper and iron impurities in the commercial zinc-containing solution and obtains the specified solution with a content of at least 100 g / l of zinc.

It was found that conducting autoclave oxidative leaching in the first stage at a molar ratio of H ₂ SO ₄ : Zn of less than 0.85 leads to a decrease in the zinc content in the solution, while an excess of the claimed ratio (more than 1.12) contributes to an increase in the content in the commodity solution copper and iron (see table, experiments NN 4, 5).

Carrying out autoclaved oxidative leaching in the second stage with a molar ratio of H ₂ SO ₄ : Zn less than the declared lower limit of 0.85 leads to a decrease in the zinc content in the solution (experiment No. 8), while exceeding the value of the claimed ratio (more than 1.12 ) helps to increase the content in the commodity solution of copper and iron (experiment No. 9).

 It was experimentally found that during the autoclave leaching process at a temperature below the melting point of sulfur, the zinc content in the solution decreases (experiment No. 6).

 In addition, there is know-how regarding the separation of liquid and solid phases after each leaching stage, as a result of which a well-washed residue and washing water is provided, consisting of at least 85% of the mother liquor and sent to the general cycle.

 The following are examples confirming the possibility of implementing the claimed invention to obtain the above technical result.

Example 1
The experiments were carried out with a concentrate containing,%: 3 zinc, 19.3 copper, 32.7 iron, 41.2 sulfur.

Part of the crushed material (300 g) was pulped up with a solution containing sulfuric acid and zinc sulfate. The liquid part of the pulp was composed of reverse electrolyte (64.5 ml) and a second stage autoclave leaching solution (367.5 ml). The molar ratio of H ₂ SO ₄ : Zn was 1.12.

The resulting pulp was placed in an autoclave (1 L volume) with mechanical stirring. Autoclave oxidative leaching was carried out under an oxygen pressure of 0.3 MPa at a temperature of 120 ^o C.

 As a result of the first leaching stage, a zinc-containing solution was obtained, the zinc content was 122 g / l, and an insoluble residue containing,%: 19.6 copper, 0.15 zinc, 33.6 iron in the form of sulfides, lead and precious metals.

The resulting zinc-containing solution was sent to the second leaching stage, to which the remainder of the starting material (300 g) was fed, while the molar ratio of H ₂ SO ₄ : Zn was 1.12.

Autoclave oxidative leaching was carried out under an oxygen pressure of 0.3 MPa and a temperature of 120 ^o C.

 The result was a solution containing 122 g / l of zinc and an insoluble residue containing,%: 19.1 copper, 0.16 zinc, 33.8 iron, lead and noble metals.

 The insoluble residues after the first and second leaching stages are combined and sent for processing by known methods, for example, autogenous smelting, followed by copper cathode and precious metals.

 The results of the experimental studies are shown in the table (experiments NN 1-9).

Example 2
The experiments were carried out with a concentrate containing,%: 10 zinc, 15.8 copper, 29.2 iron, 40.5 sulfur.

Part of the crushed material (300 g) was pulped up with a solution containing sulfuric acid and zinc sulfate. The liquid part of the pulp was composed of reverse electrolyte (132 ml) and a second stage autoclave leaching solution (318 ml). The molar ratio of H ₂ SO ₄ : Zn was 0.85.

The resulting pulp was placed in an autoclave (1 L volume) with mechanical stirring. Autoclave oxidative leaching was carried out under an oxygen pressure of 0.4 MPa at a temperature of 120 ^o C.

 As a result of the first leaching stage, a zinc-containing solution was obtained (zinc content 136 g / l) and an insoluble residue containing,%: 16.8 copper; 0.1 zinc; 31.1 iron in the form of sulfides, lead and precious metals.

The resulting zinc-containing solution was sent to the second leaching stage, to which the remainder of the starting material (300 g) was fed, while the molar ratio of H ₂ SO ₄ : Zn was 1.12.

Autoclave oxidative leaching was carried out under an oxygen pressure of 0.4 MPa and a temperature of 120 ^o C.

 The result was a solution containing 136 g / l of zinc and an insoluble residue containing,%: 16.5 copper; 0.11 zinc; 31.3 iron, lead and noble metals, which are combined with the insoluble residue of the first leaching stage and sent to autogenous smelting, followed by cathode copper production.

 The results of experimental studies are shown in the table (experiments NN 10, 11).

Example 3
The experiments were carried out with a concentrate containing,%: 18 zinc, 12.8 copper, 24.2 iron, 40.0 sulfur.

Part of the crushed material (300 g) was pulped up with a solution containing sulfuric acid and zinc sulfate. The liquid part of the pulp was composed of reverse electrolyte (457 ml) and a second stage autoclave leaching solution (177 ml). The molar ratio of H ₂ SO ₄ : Zn was 0.85.

The resulting pulp was placed in an autoclave (1 L volume) with mechanical stirring. Autoclave oxidative leaching was carried out under an oxygen pressure of 0.5 MPa at a temperature of 120 ^o C.

 As a result of the first leaching stage, a zinc-containing solution was obtained (zinc content 155 g / l) and an insoluble residue containing,%: 14.2 copper; 0.52 zinc; 27.1 iron in the form of sulfides, lead and precious metals.

The resulting zinc-containing solution was sent to the second leaching stage, to which the remainder of the starting material (300 g) was fed, while the molar ratio of H ₂ SO ₄ : Zn was 1.12.

Autoclave oxidative leaching was carried out under an oxygen pressure of 0.5 MPa and a temperature of 120 ^o C.

 The result was a solution containing 155 g / l of zinc and an insoluble residue containing,%: 14.1 copper; 0.51 zinc; 27.0 iron, lead and noble metals, which are combined with the insoluble residue of the first leaching stage and sent to autogenous smelting, followed by cathode copper production.

 The results of the experimental studies are shown in the table (experiments NN 12, 13).

 The table above compares the indicators of the proposed method (experiments NN 1, 2, 3, 7, 10, 12) and experiments, the conditions for which go beyond the limits regulated by the claims (experiments NN 4, 5, 6, 8, 9, 11 , thirteen).

 As can be seen from the materials presented, only the totality of the claimed features provides the opportunity to achieve optimal performance of the processing process of sulfide copper-zinc materials. In violation of the claimed ratios of the components, a deterioration in the desired characteristics is observed (experiments NN 4, 5, 6, 8, 9, 11, 13).

 Thus, the claimed invention successfully solves the problem of efficient processing of sulfide copper-zinc materials with a low zinc content, allows for optimal process performance and quality of a commercial product.

Claims (1)

A method of processing sulfide copper-zinc concentrates, including autoclave oxidative leaching of a portion of the crushed starting material under oxygen pressure at a temperature above the melting point of sulfur to obtain a zinc-containing solution and an insoluble residue containing copper, zinc, iron in the form of sulfides, lead and precious metals, the direction of the obtained zinc-containing solution to the next leaching stage, which serves part of the source material, obtaining a zinc-containing solution and non-growth Orim residue and the zinc solution purification from impurities, characterized in that the autoclave oxidative leaching process in a first step carried out at a molar ratio of H ₂ SO _4: Zn, equal to 0.85 - 1.12, the second leaching step is carried out by autoclave oxidative leaching temperature above the melting point of sulfur and a molar ratio of H ₂ SO ₄ : Zn equal to 0.85 - 1.12, to obtain a solution containing at least 100 g / l of zinc, and insoluble residues containing copper, iron, lead and precious metals direct for processing and known methods.

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