Methods for pre-separation of oxides and release agents on copper anode surface and methods for resource utilization of slag.

Abstract

This invention discloses a method for pre-separating oxides and release agents from the surface of copper anodes and a method for resource utilization of the slag. The method involves circulating a sulfuric acid solution into a continuous pre-separation reaction tank; immersing the copper anode body in the sulfuric acid solution, introducing gas, controlling the initial concentration of the sulfuric acid solution, heating to a certain temperature, reacting for a certain time, and after the reaction is complete, hoisting the copper anode from the mixture for electrolytic refining; and filtering the mixture to obtain a pre-separated liquid and copper-barium mixed slag. This invention, by pre-separating oxides and release agents from the surface of the copper anode, can significantly reduce the occurrence of anode passivation, lower the cell voltage during subsequent copper electrolytic refining, reduce electrolytic energy consumption, improve the quality of copper anode sludge, and reduce the cost of copper anode sludge treatment. The copper-barium mixed slag from the process can be subjected to a two-stage pressure leaching using waste acid from the secondary final liquid produced in the electrolyte purification process, fully recovering copper while obtaining reusable barium sulfate, effectively improving resource utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of copper electrolytic refining technology, specifically to a method for pre-separation of oxides and release agents on the surface of copper anodes and a method for resource utilization of slag. Background Technology

[0002] Currently, controlling anode passivation and reducing energy consumption in copper electrolysis remains a significant challenge for the industry. Oxides and release agents on the copper anode surface are key factors in anode passivation. During copper anode casting, residual oxygen in the molten copper and oxygen abundant in the air are mostly released onto the copper surface and form oxides that coat the anode surface. Simultaneously, to facilitate demolding, a release agent (mainly barium sulfate) is typically sprayed onto the mold surface, with some of this agent adhering to the anode surface. During electrolysis, because both the anode surface oxides and the release agent are semiconductors or even insulators, they hinder anode dissolution, leading to anode passivation. Furthermore, the release agent deposits at the bottom of the electrolytic cell, entering the copper anode sludge and reducing its quality, thus increasing processing costs.

[0003] Therefore, it is of great significance to develop a method that can reduce electrolysis energy consumption, improve the quality of copper anode mud, reduce the cost of copper anode mud treatment, and enhance the efficiency of resource utilization. Summary of the Invention

[0004] This invention discloses a method for pre-separation of oxides and release agents on the surface of copper anodes and a method for resource utilization of slag, in order to solve any of the above-mentioned and other potential problems in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for pre-separation of oxides and release agents on the surface of copper anodes, the pre-separation method specifically including the following steps:

[0006] S1) The sulfuric acid-containing solution is circulated into a continuous pre-separation reaction tank;

[0007] S2) Immerse the copper anode body in the sulfuric acid solution, blow in gas, control the initial concentration of the sulfuric acid solution, heat to a certain temperature, react for a certain time, and after the reaction is completed, lift the copper anode out of the mixture and send it for electrolytic refining.

[0008] S3) Filter the mixture from S2) to obtain a pre-separated liquid and a copper-barium mixed slag.

[0009] Furthermore, the sulfuric acid solution in S1) is the secondary final solution produced by the copper electrolyte purification process, that is, the solution after electrowinning to remove copper and impurities.

[0010] Furthermore, the gas in S2) is air, the initial sulfuric acid concentration is 250-300 g / L, the temperature is 60-70°C, and the reaction time is 3-5 minutes.

[0011] Furthermore, the average copper leaching rate in the pre-separation method is not less than 97.6%.

[0012] Another object of the present invention is to provide a method for the resource utilization of copper-barium mixed slag obtained by the separation method described above, the method specifically including the following steps:

[0013] Step 1) Primary separation of copper and barium: The obtained copper and barium mixed slag, the secondary final liquid produced by the copper electrolyte purification process, and the secondary leachate obtained from the secondary separation of copper and barium are subjected to a pressurized oxidation reaction under certain solid-liquid ratio, temperature, and pressure conditions. After the reaction is completed, the mixture is filtered to obtain primary leachate and primary barium sulfate slag.

[0014] Step 2) Secondary separation of copper and barium: The primary barium sulfate residue obtained in step 1) is mixed with the secondary final liquid produced in the copper electrolyte purification process. After mixing, a secondary pressure leaching is performed. After the reaction is completed, the mixture is filtered and washed to obtain a secondary leaching solution and a secondary barium sulfate residue.

[0015] Step 3) Return the pre-separated liquid and primary leaching liquid obtained in Step 2) to the electrolysis system, and reuse the secondary barium sulfate residue in the copper casting process of the smelting anode furnace.

[0016] Furthermore, the specific process parameters in step 1) are: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 90-95°C, leaching time ≥4h, sulfuric acid concentration 120-150 g / L, and liquid-solid ratio 8-9:1.

[0017] Furthermore, the specific process parameters in step 2) are: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 95-100℃, leaching time ≥4h, sulfuric acid concentration 200-250 g / L, and liquid-solid ratio 8-9:1.

[0018] Furthermore, the copper removal rate of the method reaches over 99.6%, and the leachate is returned to the copper electrolysis process for reuse; the obtained barium sulfate residue contains no less than 58% barium, which is equivalent to a barium sulfate content of over 98.6%.

[0019] The beneficial effects of this invention are as follows: In the first stage, the copper anode is effectively removed from its surface by secondary final solution acid washing, thus perfectly solving the anode passivation problem during copper electrolysis. In the second stage, the copper-barium mixed slag obtained from the first stage acid washing is subjected to two-stage pressure leaching, resulting in primary and secondary separation of copper and barium to obtain barium sulfate slag and copper sulfate solution. The barium sulfate slag contains less than 0.5% copper and more than 57% barium (equivalent to more than 98% barium sulfate), meeting the requirements for use as a release agent in copper anode casting. The copper sulfate solution can be completely returned to the electrolysis process, achieving effective separation of copper and barium and efficient utilization of barium sulfate. Simultaneously, the entire process fully utilizes the waste acid in the secondary final solution produced during the electrolyte purification process, resulting in zero chemical reagent consumption costs. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of a method for pre-separating oxides and release agents on the surface of a copper anode according to the present invention. Detailed Implementation

[0021] like Figure 1 As shown, the present invention provides a method for pre-separation and resource utilization of oxides and release agents on the surface of copper anodes, comprising the following steps:

[0022] S1) Pre-separation of surface oxides and release agent: A continuous pre-separation reaction tank is set up. The high-acid (copper, arsenic, and nickel removal) secondary final liquid produced in the copper electrolyte purification process is circulated into the reaction tank. Process waste acid with a sulfuric acid concentration of 400 g / L is circulated in, immersing the anode body in the acidic solution. Leaching is carried out under certain acid concentration and temperature conditions. After reacting for 3-5 minutes, the copper anode is hoisted out and sent for electrolytic refining. The mixed solution is filtered to obtain copper sulfate solution and copper-barium mixed slag.

[0023] S2) Copper-barium primary separation: The copper-barium mixed slag obtained in S1) is subjected to a pressure oxidation reaction with the secondary final liquid produced in the copper electrolyte purification process and the secondary leachate obtained from the secondary separation of copper and barium under certain solid-liquid ratio, temperature and pressure conditions. After the reaction is completed, the mixture is filtered to obtain primary leachate and primary barium sulfate slag.

[0024] S3) Secondary separation of copper and barium: The secondary final liquid produced by the primary barium sulfate slag and copper electrolyte purification process is mixed and then subjected to secondary pressure leaching. After the reaction is completed, the mixture is filtered and washed to obtain secondary leachate and secondary barium sulfate slag.

[0025] The copper sulfate solution obtained in step S1) is returned to the copper electrolysis process as a supplementary electrolyte.

[0026] The primary leachate obtained in step S2) is returned to the copper electrolysis process as a supplementary electrolyte.

[0027] The secondary leachate obtained in step S3) is reused as the mother liquor in step S2), and the secondary barium sulfate slag is sent to the copper casting process of the smelting anode furnace as a release agent.

[0028] Furthermore, in step S1), the pre-separation process of surface oxides and release agent is controlled with a sulfuric acid concentration of 250-280 g / L, a temperature of 60-70°C, a reaction time of 3-5 minutes, and air blowing at normal pressure. The blowing intensity is required to generate a bubble film on the surface of the reaction solution.

[0029] Furthermore, the control parameters for the copper-barium separation process in S2) are as follows: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 90-95°C, leaching time ≥4h, sulfuric acid concentration 120-150 g / L, and liquid-solid ratio 8-9:1.

[0030] Furthermore, the control parameters for the copper-barium secondary separation process (S2) are: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 95-100℃, leaching time ≥4h, sulfuric acid concentration 200-250 g / L, and liquid-solid ratio 8-9:1.

[0031] The present invention will be further described below with reference to specific embodiments:

[0032] Examples 1-2

[0033] The experiment was conducted according to the above method. The experiment content of Example 1 is stage one, including step S1: pre-separation of surface oxide and release agent, with a total of three sets of experiments.

[0034] The process parameters for Example 1 are shown in the table below:

[0035]

[0036]

[0037] The results of the pre-separation experiment (S1) of surface oxides and release agent are shown in the table below:

[0038] Table 2. Composition of the pre-separation liquid obtained from the pre-separation process of surface oxides and release agent / g / L:

[0039] Table 3. Composition of copper-barium mixed slag obtained from the pre-separation process of surface oxides and release agents / %

[0040]

[0041] Table 4. Electrolytic cell voltage during the first 0-3 hours of electrolytic refining for anodes with and without pre-separation:

[0042]

[0043]

[0044] After the oxides and release agent on the copper anode surface are pre-separated, the appearance quality of the copper anode surface is improved, and the electrolytic cell voltage of the treated copper anode decreases, thus solving the passivation problem in the electrolysis process.

[0045] The experiment was conducted according to the above method. Example 2's experiment was stage two, including steps (S2) and (S3): primary and secondary separation of copper and barium, totaling three sets of experiments. The experimental parameters for Example 2 are shown in the table below:

[0046]

[0047]

[0048] The results of the copper-barium separation experiment (S2) are shown in the table below:

[0049] Table 5. Composition of the primary leachate obtained from the first copper-barium separation experiment (S2) / g / L:

[0050] Table 6. Composition of primary barium sulfate slag obtained from the primary copper-barium separation experiment (S2) / %:

[0051] In this process, the secondary leaching solution is returned as mother liquor to the primary copper-barium separation step. This fully utilizes the sulfuric acid in the secondary leaching solution, effectively reducing the initial acidity of the leaching process, lowering processing costs, and effectively resolving the system's water balance issue. The average copper leaching rate is 97.6%, while barium is virtually not leached out.

[0052] The results of the copper-barium secondary separation experiment (S3) are shown in the table below:

[0053] Table 7 Composition of the secondary leachate obtained from the copper-barium secondary separation experiment (S3) / g / L

[0054]

[0055]

[0056] Table 8. Composition of secondary barium sulfate slag obtained from the secondary separation experiment of copper and barium (S3) / %:

[0057]

[0058] After two copper-barium separation processes, the copper removal rate reached over 99.6%, and the leachate was returned to the copper electrolysis process for reuse. The resulting barium sulfate slag contained 58% barium, which translates to a barium sulfate content of over 98.6%, fully meeting the standards for release agents used in copper anode casting and achieving the goal of comprehensive utilization of copper and barium.

[0059] The foregoing has provided a detailed description of a method for pre-separation of copper anode surface oxides and release agents, as well as a method for resource utilization of slag, provided in the embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas; furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

[0060] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0061] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0062] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0063] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A method for the resource utilization of copper-barium mixed slag, characterized in that, The copper-barium mixed slag is obtained by a pre-separation method, which specifically includes the following steps: S1) The sulfuric acid-containing solution is circulated into a continuous pre-separation reaction tank; S2) Immerse the copper anode body in the sulfuric acid solution, blow in gas, control the initial concentration of the sulfuric acid solution, heat to a certain temperature, react for a certain time, and after the reaction is completed, lift the copper anode out of the mixture and send it for electrolytic refining. S3) Filter the mixture from S2) to obtain a pre-separated liquid and a copper-barium mixed slag; The method for resource utilization specifically includes the following steps: Step 1) Primary separation of copper and barium: The obtained copper and barium mixed slag, the secondary final liquid produced by the copper electrolyte purification process, and the secondary leachate obtained from the secondary separation of copper and barium are subjected to a pressurized oxidation reaction under certain solid-liquid ratio, temperature, and pressure conditions. After the reaction is completed, the mixture is filtered to obtain primary leachate and primary barium sulfate slag. Step 2) Secondary separation of copper and barium: The primary barium sulfate residue obtained in step 1) is mixed with the secondary final liquid produced in the copper electrolyte purification process. After mixing, a secondary pressure leaching is performed. After the reaction is completed, the mixture is filtered and washed to obtain a secondary leaching solution and a secondary barium sulfate residue. Step 3) Return the obtained pre-separated liquid and primary leaching liquid to the electrolysis system, and use the secondary barium sulfate slag for the copper casting process in the smelting anode furnace.

2. The method according to claim 1, characterized in that, The sulfuric acid solution in S1) is the secondary final solution produced by the copper electrolyte purification process.

3. The method according to claim 1, characterized in that, The gas in S2) is air, the initial sulfuric acid concentration is 250-300 g / L, the temperature is 60-70℃, and the reaction time is 3-5 minutes.

4. The method according to claim 1, characterized in that, The specific process parameters in step 1) are as follows: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 90-95℃, leaching time ≥4h, sulfuric acid concentration 120-150 g / L, and liquid-solid ratio 8-9:

1.

5. The method according to claim 1, characterized in that, The specific process parameters in step 2) are as follows: air oxidation, leaching pressure 0.8-1.2 MPa, leaching temperature 95-100℃, leaching time ≥4h, sulfuric acid concentration 200-250 g / L, and liquid-solid ratio 8-9:1.

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