Method for enriching and recovering indium in lead copper matte

Abstract

The invention discloses a method for enriching and recovering indium in lead copper matte, which comprises the following steps of: firstly, carrying out pressurized oxidation acid leaching on the lead copper matte, leaching copper and indium in the lead copper matte into a solution, and obtaining leached slurry after the reaction is finished; adding a neutralizing agent into the leaching slurry, stirring for reaction, neutralizing excessive sulfuric acid, and performing liquid-solid separation after the reaction is finished to obtain filtrate and filter residues; adding an additive A into the obtained filtrate, heating and stirring to precipitate the solution, and then carrying out liquid-solid separation to obtain filter residues which are indium-rich residues and can be used as raw materials for recovering indium, and using the filtrate for recovering copper. According to the method, the grade of indium in the indium-rich slag can be improved by 5-10 times compared with that of lead copper matte, follow-up indium recovery is facilitated, and the dual effect that indium enrichment and purification and Fe and As removal of the lead copper matte leachate are synchronously completed is achieved.

Description

Technical Field

[0001] The invention belongs to the field of metal extraction in hydrometallurgy, and in particular relates to a method for enriching and recovering indium in lead matte. Background Art

[0002] Lead matte is a copper-rich intermediate material produced in the lead smelting process. It is mainly used as a raw material for copper recovery. For enterprises that use lead and zinc combined smelting, the lead matte produced by the lead system will contain a small amount of indium. Since indium is a rare metal with high value, it should be recycled from the perspective of economic benefits. At present, the mainstream process for recovering indium is the "leaching-extraction" process. However, due to the low grade of indium in lead matte, generally 0.05% to 0.30%, the indium concentration in the leachate obtained by direct leaching is low, and the recovery cost of the extraction process is high, and the recovery rate is low. Patent CN110607441.A adopts the method of circulating leaching and enriching indium in the lead matte leachate, enriching the indium in the solution to more than 1.0g / L, and then sending it to the indium extraction section to recover indium. This method is only feasible for materials with high indium content, and is not feasible for lead matte with low indium grade. Because lead matte contains a certain amount of arsenic and iron, as the number of leaching liquid cycles increases, the As and Fe content in the solution also increases. During the pressurized leaching process, iron will precipitate in the form of ferric arsenate or ferrovanadium. At this time, indium will enter the precipitate together with the iron. For lead matte with a low indium content, the indium in the leachate cannot be enriched to more than 1.0g / L. The author found in actual experiments that when the lead matte contains 0.1% indium, it is difficult to increase the indium in the solution after it is enriched to 300mg / L. Patent CN104357661.A uses direct pressurized leaching to recover indium from lead matte. After the leaching liquid recovers copper, it uses P204 to extract and recover indium. This method is also only applicable to lead matte with a higher indium grade. Summary of the invention

[0003] The problem to be solved by the present invention is to enrich low-grade indium in lead matte to facilitate subsequent recovery of indium, which is specifically achieved through the following technical scheme.

[0004] A method for enriching and recovering indium in lead matte comprises the following steps:

[0005] (1) Leaching: subjecting lead matte to pressurized oxidation acid leaching, leaching as much indium as possible into the solution while ensuring the leaching rate of copper, to obtain a leached slurry;

[0006] (2) Neutralization: adding a neutralizing agent to the leaching slurry obtained in step (1), heating and stirring to react, neutralizing the excess sulfuric acid in the solution, and then filtering to obtain a filtrate and a filter residue, wherein the filter residue is sent to a lead smelting system to recover lead and silver, and the filtrate is used to recover copper and indium;

[0007] (3) Precipitation: Add additive A to the filtrate obtained in step (2), heat and stir to produce precipitation, and then filter. The obtained filter residue is indium-rich residue, which can be used to recover indium, and the filtrate is used to recover copper.

[0008] Furthermore, in step (1), the indium content in the raw material lead matte is within the range of 0.05% to 0.3%, and the conditions of oxygen pressure acid leaching are controlled as follows: reaction temperature 100 to 150° C., reaction time 4 to 8 h, liquid-to-solid ratio (volume-to-mass ratio) 5 to 10 ml / g, ferrous sulfate or ferric sulfate in an amount of 1.0% to 3.0% by mass of the lead matte is added as a catalyst, pure oxygen or compressed air is passed through the reaction process, the reaction pressure is maintained between 1.0 and 1.3 MPa, and the sulfuric acid concentration at the reaction end point is controlled to be 50 to 100 g / L;

[0009] The neutralizing agent in step (2) is one or a combination of copper-containing materials such as copper oxide, zinc-copper slag, basic copper carbonate, etc., the reaction temperature is controlled between 50 and 70° C., the reaction time is 1.0 to 3.0 h, the amount of the neutralizing agent added is determined according to the initial sulfuric acid concentration of the solution, and the sulfuric acid concentration of the solution at the reaction end point is controlled to be 10 to 30 g / L;

[0010] The additive A in step (3) is one or a combination of sodium persulfate, ammonium persulfate, potassium persulfate, sodium sulfate, potassium sulfate, calcium carbonate, calcium hydroxide and calcium oxide. During the reaction, the solution temperature is controlled at 90-100° C., the reaction time is 3-6 hours, and the amount of the additive added is 2-10 times the amount of iron ions in the solution.

[0011] Compared with the prior art, the beneficial effects and outstanding advantages of the present invention are:

[0012] 1. The indium enrichment grade is high. The indium grade in indium-rich slag can be increased by 5 to 10 times compared with lead matte;

[0013] 2. The method provided by the present invention is to first leach indium from lead matte into a solution, and then control the precipitation of iron and arsenic in the solution so that indium, iron and arsenic are precipitated together into slag to achieve the purpose of enriching indium. The present invention can enrich more than 85% of indium in the solution into slag to obtain indium-rich slag with an indium content of more than 0.7%.

[0014] 3. While enriching indium, the lead matte leaching solution is also purified, and the iron and arsenic in the solution are precipitated into the slag, which is more conducive to the subsequent copper recovery; the process operation is simple and the reagent cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a process flow chart of a method for enriching and recovering indium in lead matte. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is described in more detail below through specific embodiments, but the scope of the present invention is not limited to these embodiments.

[0017] like Figure 1 As shown, the present invention provides a method for enriching and recovering indium in lead matte, and the method comprises the following steps:

[0018] S1) leaching: subjecting the lead matte to pressurized oxidation acid leaching to obtain a leaching slurry;

[0019] S2) Neutralization: adding a certain amount of neutralizing agent to the leached slurry obtained in S1), heating and stirring to react, neutralizing the excess sulfuric acid in the solution, and then filtering to obtain a filtrate and a filter residue, and the filter residue is sent to a lead smelting system to recover lead and silver;

[0020] S3) precipitation: adding a certain amount of additive A to the filtrate obtained in S2), heating and stirring to produce precipitation, and then filtering to obtain a filter residue rich in indium.

[0021] Furthermore, the indium content in the raw material lead matte in S1) is between 0.05% and 0.3%.

[0022] Further, the oxygen pressure leaching conditions in S1) are: atmosphere is pure oxygen or compressed air, reaction pressure is 1.0-1.3 MPa, reaction temperature is 100-150° C., reaction time is 4-8 h, liquid-solid ratio is 5-10 ml / g, catalyst is added in an amount of 1.0%-3.0% by mass of lead matte, and sulfuric acid concentration at the reaction end point is controlled at 50-100 g / L;

[0023] Furthermore, the catalyst is ferrous sulfate or ferric sulfate.

[0024] Furthermore, the process parameters of the neutralization reaction in S2) are: controlling the reaction temperature between 50 and 70° C., the reaction time between 1.0 and 3.0 h, the amount of neutralizer added is determined according to the initial sulfuric acid concentration of the solution, and controlling the sulfuric acid concentration of the solution at the reaction endpoint between 10 and 30 g / L.

[0025] Furthermore, the neutralizing agent is a copper-containing material, and the copper-containing material is one or more combinations of copper oxide, zinc-copper slag, and basic copper carbonate.

[0026] Furthermore, the amount of additive A added in S3) is 2 to 10 times the amount of iron ions in the filtrate, the reaction temperature is controlled at 90 to 100° C., and the reaction time is 3.0 to 6.0 h.

[0027] Furthermore, the additive A in S3) is one or a combination of sodium persulfate, ammonium persulfate, potassium persulfate, sodium sulfate, potassium sulfate, calcium carbonate, calcium hydroxide and calcium oxide.

[0028] Indium is prepared by the above method.

[0029] Example 1

[0030] 350g of ground lead matte (Cu 37.23%, In 0.091%, As 3.95%, Fe1.23%) was placed in a pressure reactor, and 3500ml of a 140g / L sulfuric acid solution and 3.5g of ferrous sulfate were added. The reaction was carried out at 110°C, with air passing to maintain the pressure in the reactor at 1.25MPa and exhaust gas for 5.0h. After the reaction was completed, 150g of zinc-copper slag was added to the slurry, and the reaction was continued for 3.0h. 3500ml of filtrate was obtained by filtration, and the composition was: Cu 52.56g / L, In82mg / L, Fe 1148mg / L, As3125mg / L, H 2 SO 4 20g / L.

[0031] 10 g of sodium persulfate was added to the filtrate, the temperature was raised to a near boiling state, the mixture was stirred for reaction for 4.0 h and then filtered to obtain 36.94 g of filter residue (dry weight), which contained 0.76% indium.

[0032] Example 2

[0033] 350g of ground lead matte (Cu 41.82%, In 0.10%, Fe 0.68%, As 1.83%) was placed in a pressure reactor, and 3500ml of a 140g / L sulfuric acid solution and 7.0g of ferrous sulfate were added. The mixture was reacted for 5.0h at 120°C with air passing to maintain the pressure in the reactor at 1.25MPa and exhaust gas. After the reaction, 180g of zinc-copper slag was added to the slurry, and the reaction was continued for 3.0h. 3500ml of filtrate was obtained, and the composition was as follows: Cu 60.45g / L, In 92mg / L, Fe 1143.2mg / L, As 1182.4mg / L, H 2 SO 4 15g / L.

[0034] 15 g of ammonium persulfate was added to the filtrate, and the mixture was reacted at 95° C. for 3.0 h. The mixture was filtered to obtain 40.2 g of filter residue (dry weight), which contained 0.80% indium.

[0035] Example 3

[0036] 350g of ground lead matte (Cu39.82%, In 0.15%, Fe 0.98%, As1.53%) was placed in a pressure reactor, and 3500ml of a 130g / L sulfuric acid solution and 5.0g of ferrous sulfate were added. The reaction was carried out at 140°C, with air passing to maintain the pressure in the reactor at 1.25MPa and exhaust gas for 5.0h. After the reaction was completed, 150g of zinc-copper slag was added to the slurry, and the reaction was continued for 3.0h. 3500ml of filtrate was obtained, and the composition was: Cu 55.45g / L, In113mg / L, Fe 1245.2mg / L, As1442.4mg / L, H 2 SO 4 25g / L.

[0037] 20 g of sodium sulfate was added to the filtrate, and the mixture was reacted at 95° C. for 3.0 h. The mixture was filtered to obtain 53.1 g of filter residue (dry weight), which contained 0.91% indium.

[0038] The above is a detailed introduction to a method for enriching and recovering indium in lead matte provided in the embodiment of the present application. The description of the above embodiment is only used to help understand the method and its core idea of ​​the present application; at the same time, for those of ordinary skill in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0039] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0040] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0041] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A method for enriching and recovering indium in lead matte, characterized in that: The method comprises the following steps: S1) leaching: subjecting the lead matte to pressurized oxidation acid leaching to obtain a leaching slurry; S2) Neutralization: adding a certain amount of neutralizing agent to the leached slurry obtained in S1), heating and stirring to react, neutralizing the excess sulfuric acid in the solution, and then filtering to obtain a filtrate and a filter residue, and the filter residue is sent to a lead smelting system to recover lead and silver; S3) precipitation: adding a certain amount of additive A to the filtrate obtained in S2), heating and stirring to produce precipitation, and then filtering to obtain a filter residue rich in indium.

2. The method according to claim 1, characterized in that The indium content in the raw material lead matte in S1) is 0.05% to 0.3%.

3. The method according to claim 1, characterized in that The oxygen pressure leaching conditions in S1) are: atmosphere of pure oxygen or compressed air, reaction pressure of 1.0-1.3 MPa, reaction temperature of 100-150°C, reaction time of 4-8 h, liquid-solid ratio of 5-10 ml / g, addition of a catalyst of 1.0%-3.0% by mass of lead matte, and sulfuric acid concentration at the reaction end point controlled at 50-100 g / L.

4. The method according to claim 3, characterized in that The catalyst is ferrous sulfate or ferric sulfate.

5. The method according to claim 1, characterized in that The process parameters of the neutralization reaction in S2) are: controlling the reaction temperature between 50 and 70° C., the reaction time between 1.0 and 3.0 h, the amount of neutralizer added is determined according to the initial sulfuric acid concentration of the solution, and controlling the sulfuric acid concentration of the solution at the reaction end point to be between 10 and 30 g / L.

6. The method according to claim 1, characterized in that The neutralizing agent is a copper-containing material, and the copper-containing material is one or more combinations of copper oxide, zinc-copper slag, and basic copper carbonate.

7. The method according to claim 1, characterized in that The amount of additive A added in S3) is 2 to 10 times the amount of iron ions in the filtrate, the reaction temperature is controlled at 90 to 100° C., and the reaction time is 3.0 to 6.0 hours.

8. The method according to claim 1, characterized in that The additive A in S3) is one or a combination of sodium persulfate, ammonium persulfate, potassium persulfate, sodium sulfate, potassium sulfate, calcium carbonate, calcium hydroxide and calcium oxide.

9. Indium, characterized in that: The indium is prepared by the method according to any one of claims 1 to 8.

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