A potentiometric, high-recovery, emission-reducing copper anode sludge treatment process

Abstract

This invention relates to the field of non-ferrous metal smelting technology and discloses a high-recovery, emission-reducing copper anode mud treatment process with controlled potential. Each step employs a controlled potential method to regulate the metal leaching rate and reduction rate, thereby reducing the loss rate of valuable metals in each step and improving the overall metal recovery rate. A sulfidation process is used to treat the antimony-bismuth removal solution, enriching antimony and bismuth in the form of sulfides. An evaporation crystallization method is used to open most of the copper in the anode mud in the form of crude copper sulfate. While enriching antimony and bismuth, the production of basic copper carbonate is significantly reduced, eliminating the "rotary kiln selenium distillation" and "water leaching copper separation" processes, and reducing system acid expansion caused by the "rotary kiln selenium distillation" process. By using the recycled reduction solution and secondary gold separation solution as acid sources for the antimony-bismuth removal process and the primary gold separation solution, the waste acid reuse rate and valuable element recovery rate can be improved. This effectively reduces the total wastewater discharge, simplifies the process flow, and improves the recovery rate of valuable metals.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal smelting technology, specifically to a controlled potential, high recovery rate, and emission-reducing copper anode sludge treatment process. Background Technology

[0002] Copper anode slime is a byproduct of the electrolytic refining of copper anode plates obtained from pyrometallurgical copper smelting. It contains a large amount of rare and precious metals such as gold, silver, platinum, palladium, selenium, and tellurium, as well as heavy metals such as copper, lead, bismuth, tin, and antimony. It is an important source of raw materials for the recovery of rare and precious metals and non-ferrous heavy metals. The types and recovery rates of its valuable elements have become one of the important factors affecting the economic benefits of copper smelting enterprises.

[0003] Currently, the most mature process for treating copper anode sludge is a process mainly consisting of "two pretreatment steps to remove antimony and bismuth—rotary kiln sulfation roasting and selenium distillation—water leaching for copper separation—chlorination for gold and tellurium separation—sodium sulfite for silver separation." However, the existing process suffers from difficulties in processing intermediate materials (carbon copper slag and antimony-bismuth purification slag), resulting in low antimony recovery rates. Valuable elements are severely dispersed; tellurium is dispersed in antimony-bismuth purification slag, carbon copper slag, and platinum-palladium concentrate, with a recovery rate of approximately 75%; antimony is dispersed in antimony-bismuth purification slag, carbon copper slag, and silver separation slag, with a recovery rate of less than 80%. The "two pretreatment steps to remove antimony and bismuth" generate a large amount of high-chloride wastewater, requiring significant sulfuric acid replenishment during the process, leading to severe acid expansion in the system, high wastewater output, and low reuse rates. Therefore, we need to propose a potential-controlled, high-recovery, emission-reducing copper anode sludge treatment process. Summary of the Invention

[0004] The purpose of this invention is to provide a high-recovery, emission-reducing copper anode sludge treatment process with controlled potential. Each step employs a controlled potential method, which effectively regulates the metal leaching and reduction rates at each stage, reduces the loss rate of valuable metals in each step, and improves the overall metal recovery rate. A sulfidation process is used to treat the antimony-bismuth removal solution, enriching antimony and bismuth in the form of sulfides. An evaporation crystallization method is used to open most of the copper in the anode sludge in the form of crude copper sulfate. While enriching antimony and bismuth, the production of basic copper carbonate is significantly reduced, improving the sales efficiency of copper metal. The "rotary kiln selenium distillation" and "water leaching copper separation" processes are eliminated, reducing the system acid expansion caused by the "rotary kiln selenium distillation" process. By using the recycled reduction solution and the secondary gold separation solution as the acid source for the antimony-bismuth removal process and the primary gold separation solution, the waste acid reuse rate and the recovery rate of valuable elements can be improved. This effectively reduces the total wastewater discharge, simplifies the process flow, and improves the recovery rate of valuable metals, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a potential-controlled, high-recovery, emission-reducing copper anode sludge treatment process, comprising the following steps:

[0006] S1. Copper Removal Process: Copper is removed from the anode mud using chemical methods to obtain copper removal slag and copper removal liquid. The proportion of other metals in the copper removal slag increases, providing good processing conditions for subsequent processes.

[0007] S2. Concentration and Crystallization: The copper removal solution is evaporated and concentrated to obtain crude copper sulfate crystals and the crystallized solution.

[0008] S3, Antimony and Bismuth Removal Process: Add acid to the copper removal slag for reaction, and filter to obtain antimony and bismuth removal slag and antimony and bismuth removal solution;

[0009] S4. Sulfidation process: The antimony-bismuth removal solution is subjected to sulfidation treatment to generate stable antimony sulfide and bismuth sulfide.

[0010] S5. Chlorination leaching process: including

[0011] Primary chlorination: Add acid and sodium chlorate to the antimony- and bismuth-removed residue, react, and filter to obtain primary chlorination leaching residue and primary chlorination leaching solution;

[0012] Secondary chlorination: Add acid and sodium chlorate to the primary chlorination leaching residue to react, and then filter to obtain secondary chlorination leaching residue and secondary chlorination leaching solution, and the secondary chlorination leaching solution is denoted as circulating solution A;

[0013] S6. Reduction process: A reducing gas is introduced into the primary chlorination leaching solution to carry out the reaction, and then filtered to obtain reduction residue and reduced solution. The reduced solution is denoted as circulating solution B.

[0014] Preferably, in step S1, a sulfuric acid solution with a concentration of 220 g / L-300 g / L is added to the anode mud for reaction. The reaction temperature is controlled at 50-90℃, the liquid-solid ratio between the sulfuric acid solution and the anode mud is 4-6:1, and the anode mud is aerated for 6-10 hours during the reaction to remove copper, thereby obtaining copper-removed slag and copper-removed liquid.

[0015] Preferably, in step 2, when the copper removal solution is heated and evaporated, the water content in the copper removal solution decreases, which increases the concentration of copper ions, reaches saturation, and forms crude copper sulfate crystals, thereby enriching copper ions.

[0016] Preferably, in step S3, the concentration of the acid solution is 220-300 g / L, the liquid-solid ratio of the acid solution to the copper removal slag is 6-10:1, the acid solution is a mixture of sulfuric acid and hydrochloric acid, wherein the concentration of sulfuric acid is 100-200 g / L, the concentration of hydrochloric acid is 50-150 g / L, the reaction temperature of the copper removal slag and the acid solution is 60-90℃, and the copper removal slag is subjected to antimony removal and bismuth removal under the condition of chloride ion concentration of 120-200 g / L. After the reaction proceeds for 2-4 hours, sulfur dioxide gas is continuously introduced into the mixture of acid solution and copper removal slag for 1-4 hours until the potential of the mixture is lower than 300 mV, in order to inhibit tellurium leaching.

[0017] Preferably, in step S4, during the sulfidation treatment, sodium hydrosulfide or hydrogen sulfide is added to the antimony-bismuth removal solution to react and enrich the antimony and bismuth in the solution, thereby obtaining sulfidation slag and sulfidation liquid.

[0018] Preferably, in step S5, during the primary chlorination, the acid solution added to the antimony-bismuth-removed slag is a mixed acid solution of sulfuric acid and hydrochloric acid, with a concentration of 220-300 g / L, wherein the concentration of sulfuric acid is 100-200 g / L, the concentration of hydrochloric acid is 50-150 g / L, and the concentration of chloride ions is 120-200 g / L. The liquid-solid ratio of the antimony-bismuth-removed slag to sodium chlorate to acid solution is 3-6:1, wherein the mass ratio of the antimony-bismuth-removed slag to sodium chlorate is 3:1. The reaction temperature for the primary chlorination is 60-90℃, the reaction time is 3-6 h, and after the reaction is completed, the potential is controlled to be above 1020 mV.

[0019] Preferably, during secondary chlorination, the acid added to the primary chlorination leaching residue is hydrochloric acid with a concentration of 100-160 g / L and a chloride ion concentration of 120-200 g / L. The liquid-solid ratio of the primary chlorination leaching residue to sodium chlorate and hydrochloric acid is 3-6:1, wherein the mass ratio of the primary chlorination leaching residue to sodium chlorate is 10:1. The reaction temperature for secondary chlorination is 60-90℃, and the reaction time is 3-6 hours. After the reaction is completed, the potential is controlled to be above 1020 mV, and the secondary chlorination leaching solution is returned to the next batch of primary chlorination leaching process.

[0020] Preferably, in step S6, sulfur dioxide gas is selected as the reducing gas. The sulfur dioxide gas reacts with the metal chlorides in the primary chlorination leaching solution to reduce the metal chlorides to elemental metals. After the reaction reaches a potential below 300mV, the enrichment of metals other than copper, antimony, and bismuth is achieved, and the reduced solution is returned to the next batch of antimony and bismuth removal process.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention employs a controlled potential method in each process, which can effectively regulate the metal leaching rate and reduction rate of each process, reduce the loss rate of valuable metals in each process, and improve the overall metal recovery rate of the process. A sulfidation process is used to treat the antimony-bismuth removal solution, enriching antimony and bismuth in the form of sulfides. An evaporation crystallization method is used to open most of the copper in the anode mud in the form of crude copper sulfate. While enriching antimony and bismuth, the amount of basic copper carbonate produced is significantly reduced, improving the sales efficiency of copper metal. The "rotary kiln selenium distillation" and "water leaching copper separation" processes are eliminated, reducing the system acid expansion caused by the "rotary kiln selenium distillation" process. By using the recycled reduction solution and the secondary gold separation solution as the acid source for the antimony-bismuth removal process and the primary gold separation solution, the waste acid reuse rate and the recovery rate of valuable elements can be improved. This effectively reduces the total wastewater discharge, simplifies the process flow, and improves the recovery rate of valuable metals. Attached Figure Description

[0023] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0025] Please see Figure 1 This invention provides a technical solution: a high-recovery, emission-reducing copper anode sludge treatment process with controlled potential, comprising the following steps:

[0026] S1. Copper Removal Process: Copper is removed from the anode mud using chemical methods to obtain copper removal slag and copper removal liquid. The proportion of other metals in the copper removal slag increases, providing good processing conditions for subsequent processes.

[0027] In step S1, a sulfuric acid solution with a concentration of 220 g / L-300 g / L is added to the anode mud for reaction. The reaction temperature is controlled at 50-90℃, and the liquid-solid ratio between the sulfuric acid solution and the anode mud is 4-6:1. During the reaction, the anode mud is aerated for 6-10 hours to remove copper, resulting in copper-removed slag and copper-removed liquid.

[0028] S2. Concentration and Crystallization: The copper removal solution is evaporated and concentrated to obtain crude copper sulfate crystals and the crystallized solution.

[0029] In step 2, when the copper removal solution is heated and evaporated, the water content in the solution decreases, which increases the concentration of copper ions until it reaches saturation and forms crude copper sulfate crystals, thus enriching the copper ions.

[0030] S3, Antimony and Bismuth Removal Process: Add acid to the copper removal slag for reaction, and filter to obtain antimony and bismuth removal slag and antimony and bismuth removal solution;

[0031] In step S3, the concentration of the acid solution is 220-300 g / L, the liquid-solid ratio of the acid solution to the copper removal slag is 6-10:1, the acid solution is a mixture of sulfuric acid and hydrochloric acid, wherein the concentration of sulfuric acid is 100-200 g / L, the concentration of hydrochloric acid is 50-150 g / L, the reaction temperature of the copper removal slag and the acid solution is 60-90℃, and the copper removal slag is subjected to antimony removal and bismuth removal under the condition of chloride ion concentration of 120-200 g / L. After the reaction has been carried out for 2-4 hours, sulfur dioxide gas is continuously introduced into the mixture of acid solution and copper removal slag for 1-4 hours until the potential of the mixture is lower than 300 mV, in order to inhibit tellurium leaching.

[0032] S4. Sulfidation process: The antimony-bismuth removal solution is subjected to sulfidation treatment to generate stable antimony sulfide and bismuth sulfide.

[0033] In step S4, during the sulfidation process, sodium hydrosulfide or hydrogen sulfide is added to the antimony-bismuth removal solution to react and enrich the antimony and bismuth in the solution, resulting in sulfidation slag and sulfidation liquid.

[0034] S5. Chlorination leaching process: including

[0035] Primary chlorination: Add acid and sodium chlorate to the antimony- and bismuth-removed residue, react, and filter to obtain primary chlorination leaching residue and primary chlorination leaching solution;

[0036] Secondary chlorination: Add acid and sodium chlorate to the primary chlorination leaching residue to react, and then filter to obtain secondary chlorination leaching residue and secondary chlorination leaching solution, and the secondary chlorination leaching solution is denoted as circulating solution A;

[0037] In step S5, during the primary chlorination, the acid solution added to the antimony-bismuth-removed slag is a mixed acid solution of sulfuric acid and hydrochloric acid, with a concentration of 220-300 g / L, wherein the concentration of sulfuric acid is 100-200 g / L, the concentration of hydrochloric acid is 50-150 g / L, and the concentration of chloride ions is 120-200 g / L. The liquid-solid ratio of antimony-bismuth-removed slag to sodium chlorate to acid solution is 3-6:1, wherein the mass ratio of antimony-bismuth-removed slag to sodium chlorate is 3:1. The reaction temperature for the primary chlorination is 60-90℃, and the reaction time is 3-6 h. After the reaction is completed, the potential is controlled to be above 1020 mV.

[0038] During secondary chlorination, the acid solution added to the primary chlorination leaching residue is hydrochloric acid with a concentration of 100-160 g / L and a chloride ion concentration of 120-200 g / L. The liquid-solid ratio of the primary chlorination leaching residue to sodium chlorate and hydrochloric acid is 3-6:1, and the mass ratio of the primary chlorination leaching residue to sodium chlorate is 10:1. The reaction temperature for secondary chlorination is 60-90℃, and the reaction time is 3-6 hours. After the reaction is completed, the potential is controlled above 1020 mV, and the secondary chlorination leaching solution is returned to the next batch of primary chlorination leaching process.

[0039] S6. Reduction process: A reducing gas is introduced into the primary chlorination leaching solution to carry out the reaction, and then filtered to obtain reduction residue and reduced solution. The reduced solution is denoted as circulating solution B.

[0040] In step S6, sulfur dioxide gas is selected as the reducing gas. The sulfur dioxide gas reacts with the metal chlorides in the primary chlorination leaching solution to reduce the metal chlorides to elemental metals. When the reaction reaches a potential below 300mV, the enrichment of metals other than copper, antimony, and bismuth is achieved, and the reduced solution is returned to the next batch of antimony and bismuth removal process.

[0041] The specific implementation process of this embodiment is as follows:

[0042] Weigh 200g of anode mud into a beaker, controlling the liquid-to-solid ratio at 6:1 and the acidity at 220g / L. Heat in a water bath at 70℃ for 6 hours, continuously bubbling air during the reaction. After the reaction, filter to obtain copper-removed slag and copper-removed liquid.

[0043] The copper removal solution was placed in a beaker and evaporated and concentrated. Crystallization was completed when the sulfuric acid concentration in the solution reached 340–440 g / L at a cold state. The solution was then filtered to obtain crude copper sulfate crystals and the resulting liquid. The copper removal residue was weighed and placed in a beaker, with the liquid-to-solid ratio controlled at 6:1, H₂SO₄ = 140 g / L, HCl = 70 g / L, and Cl₂... - =150 g / L, heated to 80℃ in a water bath for reaction, SO2 was introduced after 2 hours of reaction until the potential was below 300 mV, and the reaction was filtered to obtain antimony-removed bismuth residue and antimony-removed bismuth solution.

[0044] Weigh the antimony-bismuth removal solution obtained from the antimony removal process and place it in a beaker. Slowly add 32% wt sodium hydrosulfide solution to the bottom of the solution. Use titration to determine the endpoint. After the reaction is complete, filter to obtain sulfidation slag and sulfidation liquid.

[0045] Weigh the antimony-bismuth removal residue obtained from the antimony removal process into a beaker, controlling the liquid-to-solid ratio at 4:1, H2SO4 = 150 g / L, HCl = 80 g / L, Cl... - =150 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 3:1, heat to 70℃ and react for 3h. After the reaction is completed, the potential is measured to be 1034 mV. Filter to obtain primary chlorination leaching residue and primary chlorination leaching solution.

[0046] Weigh out the primary chlorination leaching residue and place it in a beaker, controlling the liquid-to-solid ratio at 4:1, H2SO4 = 150 g / L, HCl = 80 g / L, Cl... -=150 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 10:1, react at 70℃ for 3h, after the reaction is completed, the potential is measured to be 1024 mV, filter, and obtain secondary chlorination leaching residue and secondary chlorination leaching solution, wherein the secondary chlorination leaching solution is denoted as circulating liquid A.

[0047] Weigh the primary chlorination leachate obtained from the primary chlorination leaching process into a beaker, and control the reaction temperature at 35°C. o C is then introduced with SO2, and after the potential drops to the steady-state period, the reaction continues for 30 minutes, with the temperature increased to 80°C. o C. After the potential continues to drop steadily to 300mV, continue the reaction for 30 minutes. After the reaction is completed, filter to obtain reduction residue and reduction liquid, of which the reduction liquid is referred to as circulating liquid B.

[0048] The composition of the sample obtained in Example 1 was analyzed as follows:

[0049] Table 1 Material composition of each process

[0050]

[0051] Through the copper removal process, the leaching rates of copper and arsenic were 77.08% and 65.49%, respectively, and the copper and arsenic contents in the copper removal slag were reduced to 7.15% and 2.92%, respectively.

[0052] Through the antimony and bismuth removal process, the average leaching rates of antimony and bismuth were 81.35% and 85.27%, respectively, and the antimony and bismuth contents in the antimony and bismuth removal residue were reduced to 1.49% and 0.59%, respectively.

[0053] Through the sulfidation process, the sulfidation rates of copper, arsenic, antimony, and bismuth were 98.99%, 98.94%, 99.00%, and 98.99%, respectively.

[0054] Through primary and secondary chlorination leaching, the comprehensive leaching rates of selenium, tellurium, and gold were 99.82%, 98.58%, and 98.87%, respectively. The average contents of selenium, tellurium, and gold in the secondary chlorination leaching residue decreased to 0.07%, 0.27%, and 14.3 g / t, respectively.

[0055] Through the reduction process, the selenium, tellurium, and gold contents in the reduction residue were 59.24%, 15.96%, and 26118.50 g / t, respectively, with reduction rates of 99.79%, 97.80%, and 99.93%, respectively. Example 2

[0056] The similarities with Example 1 will not be repeated here; the differences are...

[0057] The specific implementation process of this embodiment is as follows:

[0058] Weigh 200g of anode mud into a beaker, controlling the liquid-to-solid ratio at 7:1 and the acidity at 240g / L. Heat in a water bath at 80℃ for 6 hours, continuously bubbling air during the reaction. After the reaction, filter to obtain copper-removing slag and copper-removing liquid.

[0059] The copper removal solution was placed in a beaker and evaporated and concentrated. When the sulfuric acid concentration in the solution was 340-440 g / L under cold conditions, crystallization was completed and the solution was filtered to obtain crude copper sulfate crystals and the crystallized solution.

[0060] Weigh out the copper-removing slag and place it in a beaker. Add the circulating liquid B obtained in Example 1, controlling the liquid-to-solid ratio at 4:1, H2SO4 = 150 g / L, HCl = 70 g / L, Cl... - =160 g / L, heated to 80℃ in a water bath for reaction, SO2 was introduced after 2 hours of reaction until the potential was below 300 mV, and filtered after the reaction was completed to obtain antimony-bismuth-removed slag and antimony-bismuth-removed liquid.

[0061] Weigh the antimony-bismuth removal solution obtained from the antimony removal process and place it in a beaker. Slowly add 32% wt sodium hydrosulfide solution to the bottom of the solution. Use titration to determine the endpoint. After the reaction is complete, filter to obtain sulfidation slag and sulfidation liquid.

[0062] Weigh the antimony-bismuth removal residue obtained from the antimony removal process and place it in a beaker. Add circulating liquid A, controlling the liquid-to-solid ratio at 3:1, H2SO4 = 140 g / L, HCl = 80 g / L, Cl... - =120 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 3:1, heat to 70℃ and react for 3h. After the reaction is completed, the potential is measured to be 1028 mV. Filter to obtain primary chlorination leaching residue and primary chlorination leaching solution.

[0063] Weigh out the primary chlorination leaching residue and place it in a beaker, controlling the liquid-to-solid ratio at 4:1, H2SO4 = 150 g / L, HCl = 80 g / L, Cl... - =180 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 10:1, react at 70℃ for 3h, after the reaction is completed, the potential is measured to be 1032 mV, filter, and obtain secondary chlorination leaching residue and secondary chlorination leaching solution, wherein the secondary chlorination leaching solution is denoted as circulating liquid A1.

[0064] Weigh the primary chlorination leachate obtained from the primary chlorination leaching process into a beaker, and control the reaction temperature at 35°C. o C is then introduced with SO2, and after the potential drops to the steady-state period, the reaction continues for 30 minutes, with the temperature increased to 80°C. o C. After the potential continues to drop steadily to 300mV, continue the reaction for 30 minutes. After the reaction is completed, filter to obtain reduction residue and reduction liquid, wherein the reduction liquid is denoted as circulating liquid B1.

[0065] The composition of the sample obtained in Example 2 was analyzed as follows:

[0066] Table 2 Material composition of each process

[0067]

[0068] Through the copper removal process, the leaching rates of copper and arsenic were 78.19% and 69.59%, respectively, and the copper and arsenic contents in the copper removal slag were reduced to 6.46% and 2.51%, respectively.

[0069] Through the antimony and bismuth removal process, the average leaching rates of antimony and bismuth were 82.15% and 89.65%, respectively, and the antimony and bismuth contents in the antimony and bismuth removal residue were reduced to 1.83% and 0.71%, respectively.

[0070] Through the sulfidation process, the sulfidation rates of copper, arsenic, antimony, and bismuth were 98.79%, 99.48%, 98.80%, and 99.19%, respectively.

[0071] Through primary and secondary chlorination leaching, the comprehensive leaching rates of selenium, tellurium, and gold were 99.72%, 99.58%, and 99.27%, respectively. The average contents of selenium, tellurium, and gold in the secondary chlorination leaching residue decreased to 0.08%, 0.08%, and 64.00 g / t, respectively.

[0072] Through the reduction process, the selenium, tellurium, and gold contents in the reduction residue were 41.51%, 25.50%, and 18615.90 g / t, respectively, with reduction rates of 99.69%, 98.80%, and 99.94%, respectively. Example 3

[0073] The similarities with the above embodiments will not be repeated, the differences are as follows:

[0074] The specific implementation process of this embodiment is as follows:

[0075] Weigh 200g of anode mud into a beaker, controlling the liquid-to-solid ratio at 6:1 and the acidity at 250g / L. Heat in a water bath at 80℃ for 8 hours, continuously bubbling air during the reaction. After the reaction, filter to obtain copper-removing slag and copper-removing liquid.

[0076] The copper removal solution was placed in a beaker and evaporated and concentrated. Crystallization was completed when the sulfuric acid concentration in the solution reached 340–440 g / L under cold conditions. The solution was then filtered to obtain crude copper sulfate crystals and the crystallized liquid. The copper removal slag was weighed and placed in a beaker, and the circulating liquid B1 obtained in Example 2 was added, controlling the liquid-to-solid ratio at 4:1, H2SO4 = 160 g / L, HCl = 80 g / L, and Cl... -=180 g / L, heated to 80℃ in a water bath for reaction, SO2 was introduced after 2 hours of reaction until the potential was below 300 mV, and filtered after the reaction was completed to obtain antimony-bismuth-removed slag and antimony-bismuth-removed liquid.

[0077] Weigh the antimony-bismuth removal solution obtained from the antimony removal process and place it in a beaker. Slowly add 32% wt sodium hydrosulfide solution to the bottom of the solution. Use titration to determine the endpoint. After the reaction is complete, filter to obtain sulfidation slag and sulfidation liquid.

[0078] Weigh the antimony-bismuth removal residue obtained from the antimony removal process and place it in a beaker. Add the circulating liquid A1 obtained in Example 2, controlling the liquid-to-solid ratio at 3:1, H2SO4 = 160 g / L, HCl = 80 g / L, Cl... - =150 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 3:1, heat to 70℃ and react for 3h. After the reaction is completed, the potential is measured to be 1023 mV. Filter to obtain primary chlorination leaching residue and primary chlorination leaching solution.

[0079] Weigh out the primary chlorination leaching residue and place it in a beaker, controlling the liquid-to-solid ratio at 3:1, H2SO4 = 160 g / L, HCl = 80 g / L, Cl... - =150 g / L, add sodium chlorate according to M dry antimony and bismuth desulfurization residue: M sodium chlorate = 10:1, react at 70℃ for 3h, after the reaction is completed, the potential is measured to be 1022 mV, filter, and obtain secondary chlorination leaching residue and secondary chlorination leaching solution, wherein the secondary chlorination leaching solution is denoted as circulating liquid A2.

[0080] Weigh the primary chlorination leachate obtained from the primary chlorination leaching process into a beaker, and control the reaction temperature at 35°C. o C is then introduced with SO2, and after the potential drops to the steady-state period, the reaction continues for 30 minutes, with the temperature increased to 80°C. o C. After the potential continues to drop steadily to 300mV, continue the reaction for 30 minutes. After the reaction is completed, filter to obtain reduction residue and reduction liquid, wherein the reduction liquid is denoted as circulating liquid B2.

[0081] The composition of the sample obtained in Example 3 is shown below:

[0082] Table 3 Material composition of each process

[0083]

[0084] Through the copper removal process, the leaching rates of copper and arsenic were 80.13% and 68.99%, respectively, and the copper and arsenic contents in the copper removal slag were reduced to 7.71% and 2.76%, respectively.

[0085] Through the antimony and bismuth removal process, the average leaching rates of antimony and bismuth were 85.32% and 83.52%, respectively, and the antimony and bismuth contents in the antimony and bismuth removal slag were reduced to 1.71% and 0.71%, respectively. Through the sulfidation process, the sulfidation rates of copper, arsenic, antimony, and bismuth were 99.29%, 99.31%, 99.11%, and 99.21%, respectively.

[0086] Through primary and secondary chlorination leaching, the comprehensive leaching rates of selenium, tellurium, and gold were 99.29%, 99.67%, and 99.35%, respectively. The average contents of selenium, tellurium, and gold in the secondary chlorination leaching residue decreased to 0.84%, 0.31%, and 57.00 g / t, respectively.

[0087] Through the reduction process, the selenium, tellurium, and gold contents in the reduction residue were 69.25%, 13.48%, and 23851.60 g / t, respectively, with reduction rates of 99.69%, 98.80%, and 99.94%, respectively.

[0088] In summary, the use of the controlled potential method in each process can effectively regulate the metal leaching rate and reduction rate, reduce the loss rate of valuable metals in each process, and improve the overall metal recovery rate of the process. The antimony and bismuth removal solution is treated with a sulfidation process to enrich antimony and bismuth in the form of sulfides. The evaporation crystallization method is used to open most of the copper in the anode mud in the form of crude copper sulfate. While enriching antimony and bismuth, the amount of basic copper carbonate produced is significantly reduced.

[0089] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A controlled-potential, high-recovery, emission-reducing copper anode sludge treatment process, characterized in that: Includes the following steps: S1. Copper Removal Process: Copper is removed from the anode mud using chemical methods to obtain copper removal slag and copper removal liquid. The proportion of other metals in the copper removal slag increases, providing good processing conditions for subsequent processes. A sulfuric acid solution with a concentration of 220 g / L-300 g / L is added to the anode mud for reaction. The reaction temperature is controlled at 50-90℃, and the liquid-solid ratio between the sulfuric acid solution and the anode mud is 4-6:

1. The anode mud is aerated for 6-10 hours during the reaction to remove copper, resulting in copper-removed slag and copper-removed liquid. S2. Concentration and Crystallization: The copper removal solution is evaporated and concentrated to obtain crude copper sulfate crystals and the crystallized solution. S3, Antimony and Bismuth Removal Process: Add acid to the copper removal slag for reaction, and filter to obtain antimony and bismuth removal slag and antimony and bismuth removal solution; The concentration of the acid solution is 220-300 g / L, and the liquid-solid ratio of the acid solution to the copper removal slag is 6-10:

1. The acid solution is a mixture of sulfuric acid and hydrochloric acid, wherein the concentration of sulfuric acid is 100-200 g / L and the concentration of hydrochloric acid is 50-150 g / L. The reaction temperature of the copper removal slag and the acid solution is 60-90℃. The copper removal slag is subjected to antimony and bismuth removal under the condition of chloride ion concentration of 120-200 g / L. After the reaction has been carried out for 2-4 hours, sulfur dioxide gas is continuously introduced into the mixture of acid solution and copper removal slag for 1-4 hours until the potential of the mixture is lower than 300 mV, in order to inhibit tellurium leaching. S4. Sulfidation process: The antimony-bismuth removal solution is subjected to sulfidation treatment to generate stable antimony sulfide and bismuth sulfide. S5. Chlorination leaching process: including Primary chlorination: Add acid and sodium chlorate to the antimony- and bismuth-removed residue, react, and filter to obtain primary chlorination leaching residue and primary chlorination leaching solution; Secondary chlorination: Add acid and sodium chlorate to the primary chlorination leaching residue, react, and filter to obtain secondary chlorination leaching residue and secondary chlorination leaching solution; During the primary chlorination process, the acid solution added to the antimony-bismuth-removed slag is a mixture of sulfuric acid and hydrochloric acid, with a concentration of 220-300 g / L. The concentration of sulfuric acid is 100-200 g / L, the concentration of hydrochloric acid is 50-150 g / L, and the concentration of chloride ions is 120-200 g / L. The liquid-solid ratio of the antimony-bismuth-removed slag to sodium chlorate to acid solution is 3-6:1, and the mass ratio of the antimony-bismuth-removed slag to sodium chlorate is 3:

1. The reaction temperature for the primary chlorination is 60-90℃, and the reaction time is 3-6 hours. After the reaction is completed, the potential is controlled to be above 1020 mV. During secondary chlorination, the acid solution added to the primary chlorination leaching residue is hydrochloric acid with a concentration of 100-160 g / L and a chloride ion concentration of 120-200 g / L. The liquid-solid ratio of the primary chlorination leaching residue to sodium chlorate and hydrochloric acid is 3-6:1, and the mass ratio of the primary chlorination leaching residue to sodium chlorate is 10:

1. The reaction temperature for secondary chlorination is 60-90℃, and the reaction time is 3-6 hours. After the reaction is completed, the potential is controlled above 1020 mV, and the secondary chlorination leaching solution is returned to the next batch of primary chlorination leaching process. S6. Reduction process: A reducing gas is introduced into the primary chlorination leaching solution to carry out the reaction, and then filtered to obtain reduction residue and reduced solution. Sulfur dioxide is used as the reducing gas. The sulfur dioxide reacts with the metal chlorides in the primary chlorination leaching solution to reduce the metal chlorides to elemental metals. When the reaction reaches a potential below 300mV, the metals other than copper, antimony, and bismuth are enriched. The reduced solution is then returned to the next batch of antimony and bismuth removal process.

2. The copper anode sludge treatment process with controlled potential, high recovery rate, and emission reduction according to claim 1, characterized in that: In step 2, when the copper removal solution is heated and evaporated, the water content in the solution decreases, which increases the concentration of copper ions until it reaches saturation and forms crude copper sulfate crystals, thus enriching the copper ions.

3. The copper anode sludge treatment process with controlled potential, high recovery rate, and emission reduction according to claim 1, characterized in that: In step S4, during the sulfidation process, sodium hydrosulfide or hydrogen sulfide is added to the antimony-bismuth removal solution to react and enrich the antimony and bismuth in the solution, resulting in sulfidation slag and sulfidation liquid.

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