Method for enriching and recovering gold from copper anode slime

Abstract

The invention relates to the technical field of rare and noble metal metallurgy, in particular to a method for enriching and recovering gold from copper anode slime, which specifically comprises the following steps: (1) adding a preset amount of concentrated sulfuric acid into the copper anode slime, mixing and curing for a preset time to obtain cured slag, adding water into the cured slag, dissolving copper sulfate in the cured slag into water, and stirring to obtain a concentrated sulfuric acid solution; filtering to separate out copper to obtain a first filter residue; (2) adding a preset amount of hydrochloric acid solution into the first filter residue, heating to a preset temperature, introducing chlorine to control the dissolution potential of the solution, carrying out selective dissolution and liquid preparation treatment on gold in the solution, and filtering to obtain tellurium-rich residue and a chloroauric acid solution; (3) carrying out flotation silver removal pretreatment on the tellurium-rich slag to obtain second filter residues, activating the second filter residues, and filtering to obtain third filter residues and an activating solution; the method has the advantages of being low in reagent cost, simple in technological process, environmentally friendly, easy to industrialize and the like, the gold recovery rate is high, and the gold recovery rate can reach 98% or above.

Description

Technical Field

[0001] The invention relates to the technical field of rare and precious metal metallurgy, and in particular to a method for enriching and recovering gold from copper anode mud. Background Art

[0002] Gold is a kind of precious metal. Due to its unique metallic properties and financial attributes, it has been sought after by everyone from ancient times to the present. Copper anode mud is a by-product produced in the process of electrolytic copper. This by-product is rich in precious metals such as gold, silver, platinum, palladium, and valuable metals such as copper, selenium, and tellurium. More than 60% of selenium and tellurium and more than 40% of gold and silver in my country come from copper anode mud. Extraction from copper anode mud is one of the important sources of gold in the world. As the price of gold continues to rise, the composition of copper anode mud is complex. Controlling the recovery cost and yield of gold in copper anode mud directly affects the economic benefits of the recycling company.

[0003] At present, the comprehensive recovery of copper anode mud usually adopts sulfuric acid roasting to separate silver and copper, alkaline roasting to separate and recover selenium and tellurium, and chlorination leaching and oxalic acid reduction to recover gold. Some precious metals such as gold will be dispersed by tellurium, resulting in the dispersion of precious metals such as gold. At the same time, during the process of chlorination dissolution of gold, tellurium will also partially dissolve into the solution, resulting in low gold and tellurium recovery rates. Therefore, it is of great significance to solve the problem of how to recover gold efficiently and at low cost.

[0004] Invention patent CN201711081760.X discloses a method for recovering rare precious metals from copper anode mud copper separation liquid, comprising the following steps: Step 1: copper anode mud copper separation liquid is strengthened to reduce rare precious metals, copper anode mud copper separation liquid is added to an acid-resistant reaction container with a heating device and a stirring device, the stirring device is turned on for stirring, the heating device is turned on for heating, an acidity regulator is added at a certain temperature, the acidity of the solution is controlled to be 0.5-75g / L, and when the solution temperature rises to 75-95°C, a reducing agent for rare precious metals is added, and the reaction is carried out for 0.5-1h to reduce the rare precious metals; Step 2: ultrafine particles are precipitated to purify the copper separation liquid in coordination with the rare precious metals, and after the reaction of step 1 is completed, the reaction temperature is maintained. A co-precipitant is added at a certain degree, and after reacting for 0.5-2h, solid-liquid separation is performed to obtain a rare precious metal concentrate and a copper separation liquid with a lower impurity content than before treatment, and rare precious metals such as gold, silver, platinum, palladium, selenium and tellurium are refined from the rare precious metal concentrate; the reducing agent in the step 1 is a reducing agent composed of one or a mixture of any three of cuprous chloride, sodium sulfite and sodium pyrosulfite, and copper powder is added, and the dosage is 0.1-5g / L; the co-precipitant in the step 2 is a mixture composed of one or a mixture of any two or more of aluminum oxide, aluminum sulfate, polyferric sulfate, ferric oxide, antimony oxide and arsenic trioxide, and active copper smelting dust is added, and the dosage is 0.1-5g / L. The present invention can pretreat the copper separation liquid through the process, which can effectively purify it and reduce the impurity content. The focus is on the efficient and coordinated recovery of rare and precious metals, so that the ionic and ultrafine particle rare and precious metals dissolved and dispersed in the copper separation liquid are effectively reduced and enriched to obtain rare and precious metal concentrates. The obtained concentrate has high valuable element grade and single element state, is a high-quality raw material source for recovering rare and precious metals, and has the advantages of strong process adaptability, high reduction rate, few impurities and high efficiency.

[0005] Invention patent CN201010179026.9 discloses a method for recovering gold, silver, bismuth, antimony and copper from lead anode mud, which is characterized by: 1. hydrochloric acid leaching, 2. smelting leaching slag, 3. silver electrolysis, 4. chlorination gold extraction, 5. sodium sulfide silver precipitation, 6. hydrolysis antimony precipitation, 7. neutralization bismuth precipitation, 8. iron replacement copper. The method of the present invention is completed by pre-oxidation treatment before wet leaching of lead anode mud, hydrochloric acid leaching at room temperature, sodium sulfide silver precipitation, hydrolysis antimony precipitation, neutralization bismuth precipitation, replacement copper precipitation, smelting leaching slag, silver electrolysis, chlorination gold extraction, and realizes the comprehensive extraction of gold, silver, bismuth, antimony and copper valuable metals from lead anode mud. The process is continuous, with low energy consumption, low pollution, easy operation and high extraction rate. It is suitable for the extraction of valuable metals from lead anode mud in the field of metal smelting.

[0006] The above methods have obvious advantages, but the gold-containing materials are all made into liquid with strong acid, and then a large amount of alkaline reagents are added to adjust the acidity, and then a large amount of oxalic acid is added to reduce the gold. This process will inevitably lead to the hydrolysis and co-precipitation of other metals during the acid adjustment process, resulting in the gold content being affected. A large amount of organic reducing reagents are added during the reduction process, and flocculants need to be added to produce ultrafine gold particles, which increases the reagent consumption and the difficulty of post-reduction liquid treatment and the unstable gold yield. As a result, the gold yield and enrichment multiple cannot be guaranteed, the auxiliary material consumption is large, and the process flow is long.

[0007] Therefore, based on the existing process of enriching and recovering gold from copper anode mud, it is of great significance to develop a process for enriching and recovering gold from copper anode mud with low auxiliary material consumption, high gold yield, environmental friendliness, low cost and short process. Summary of the invention

[0008] Features and advantages of the invention are set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0009] In order to overcome the problems of the prior art, the present invention provides a method for enriching and recovering gold from copper anode mud, which specifically comprises the following steps: (1) Add a preset amount of concentrated sulfuric acid to the copper anode mud and mix and mature for a preset time to obtain a mature slag. After the volatilized gas is absorbed by water during the maturation process, a first solution is obtained. Sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain a first filter residue; (2) After adding a preset amount of hydrochloric acid solution to the first filter residue and heating it to a preset temperature, chlorine gas is introduced and the dissolution potential of the solution is controlled, and the gold in the solution is selectively dissolved and treated to make a liquid, and then filtered to obtain a tellurium-rich residue and a chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, the second filter residue is activated, and the third filter residue and activation solution are obtained by filtration; (4) After heating the chloroauric acid solution to drive out the chlorine, the heating is stopped, and the third filter residue is added to the chloroauric acid solution. The redox potential of the solution is controlled to drop to a preset range and then the gold is replaced until the gold in the solution is completely replaced. The crude gold powder and tellurium chloride filtrate are obtained by filtration. The crude gold powder is purified to obtain metallic gold. The tellurium chloride filtrate is converted into tellurium oxide by neutralization and precipitation with alkaline solution, and then dissolved with alkali into sodium tellurate solution and sent to the electrolysis section for electrolysis to obtain metallic tellurium.

[0010] Preferably, the liquid-solid ratio of concentrated sulfuric acid to copper anode mud is 0.4-1.8:1, the aging temperature is 200°C-730°C, the aging time is 1.5h-4.5h, and the leaching solid-liquid ratio is 1:3-5.

[0011] Preferably, in step (2), the concentration of the hydrochloric acid solution is 1 mol / L-6 mol / L, the liquid-to-solid ratio of the hydrochloric acid solution to the first filter residue is 3-8:1, the heating temperature is 50°C-90°C, and the dissolution potential is 730mv-1050mv.

[0012] Preferably, in step (3), the activation treatment comprises the following steps: adding the second filter residue to pure water, heating and adding a preset amount of reducing agent for activation treatment, filtering to obtain an activated third filter residue and an activation liquid, and sending the activation liquid to a wastewater treatment section; wherein the liquid-to-solid ratio of the second filter residue to the activation liquid is 1-3:1; the reduction temperature is 40°C-90°C; the mass ratio of the reducing agent to the second filter residue is 0.01-0.1:1, and the reduction time is 0.5h-4h.

[0013] Preferably, the reducing agent is one or more of ascorbic acid, hydrazine hydrochloride, potassium borohydride and hydrazine hydrate mixed in any ratio.

[0014] Preferably, in step (4), the chlorine removal temperature is 50°C-110°C, and the chlorine removal time is 0.5h-1.5h; during the replacement process, the solution redox potential is 550mv-840mv.

[0015] Beneficial effects of the present invention: The present invention utilizes the reduction potential difference of residual tellurium from the conversion of tellurium slag to gold ions in chloroauric acid solution to achieve replacement of gold and dissolution of tellurium to make liquid. Compared with the traditional method of recovering gold, the present invention has strong selectivity for gold reduction, thorough reduction, no need to adjust the acidity of chloroauric acid solution, no need to add organic reducing agents such as oxalic acid, greatly reduces reagent consumption, avoids the problem of thick solution and difficulty in filtering caused by adding a large amount of reducing agent, and has the advantages of friendly connection of liquid treatment after gold separation. The present invention utilizes tellurium to replace and enrich gold in copper anode mud, which has the advantages of strong selectivity, thorough gold reduction, environmental friendliness, high gold yield, low cost, short process, simple process control, easy industrialization, etc., and has broad application prospects. At the same time, the present application also has the following beneficial effects: (1) Separating selenium and copper from anode mud preferentially helps to increase the gold concentration in the chloroauric acid solution generated by chlorination, thus creating favorable conditions for avoiding the generation of extremely fine gold particles in the subsequent reduction process; (2) The gold in the chloroauric acid is selectively reduced by activating the tellurium slag in the system, and tellurium is dissolved and enters the solution as tellurium chloride, which has complete reduction. In the process of tellurization, the precious metals such as gold dispersed in the tellurium slag can be returned to the main body of gold due to the tellurium capturing precious metal effect, thereby improving the gold yield. At the same time, the addition and consumption of acid regulators are avoided, and the problem of difficult liquid treatment after gold separation caused by the traditional addition of organic reagents such as oxalic acid is avoided. The present invention has the advantages of small gold and tellurium dispersion, low reagent cost, simple process flow, environmental friendliness, and easy industrialization in the process of enriching and recovering gold from copper anode mud. The gold recovery rate is high, and the gold recovery rate can reach more than 98%, and the application prospect is broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention in any sense. In the accompanying drawings: Figure 1 The present invention is a schematic flow chart of a method for enriching and recovering gold from copper anode mud in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0018] In the description of the present invention, unless otherwise specified, the terms “first”, “second”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0019] Example 1

[0020] like Figure 1 As shown, the present invention provides a method for enriching and recovering gold from copper anode mud, which specifically comprises the following steps: (1) Add 60 ml of concentrated sulfuric acid to 150 g of copper anode mud, mix the mixture, heat it to 200°C in a muffle furnace and keep it warm for 3.5 hours, and obtain mature slag after aging. After the volatilized selenium dioxide gas is absorbed by water during the aging process, a first solution is obtained, and sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain the first filter residue; the leaching solid-liquid ratio is 1:3; (2) Add 500 ml of 1 mol / L hydrochloric acid solution to the first filter residue, with a liquid-to-solid ratio of 3:1 between the hydrochloric acid solution and the first filter residue, and heat to a constant temperature of 75°C, introduce chlorine gas and control the solution's dissolution potential to 930 mv, selectively dissolve the gold in the solution for 1.5 hours, and filter to obtain tellurium-rich residue and chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, and the second filter residue is activated and filtered to obtain a third filter residue and an activation solution; the activation treatment comprises the following steps: adding the second filter residue to 50 ml of pure water, heating to 90° C. and dripping 3 ml of hydrazine hydrate solution to react for 0.5 h for activation treatment, wherein the mass ratio of the reducing agent hydrazine hydrate solution to the second filter residue is 0.01:1, filtering to obtain an activated third filter residue and an activation solution, wherein the liquid-to-solid ratio of the second filter residue to the activation solution is 1:1, and the activation solution is sent to the wastewater treatment section; (4). Heat the chloroauric acid solution to 60°C to remove chlorine for 0.5h and then stop heating. Then add the third filter residue to the chloroauric acid solution, control the redox potential of the solution to drop to 550mv-600mv and then replace the gold until the gold in the solution is completely replaced. Filter to obtain coarse gold powder and tellurium chloride filtrate; electrolyze and purify the coarse gold powder to obtain gold powder containing 99.98% gold, with a gold yield of 98.33%; neutralize the tellurium chloride filtrate with a mass fraction of 20-40% sodium hydroxide solution to a pH of 5 and precipitate to convert into tellurium oxide. Use a mass fraction of 10-15% sodium hydroxide solution to adjust the pH to 14 for the tellurium oxide precipitate. Dissolve the tellurium oxide into sodium tellurate solution and then send it to the electrolysis section for electrolysis to obtain metallic tellurium.

[0021] Example 2

[0022] This embodiment provides a method for enriching and recovering gold from copper anode mud, which specifically includes the following steps: (1) Add 166 ml of concentrated sulfuric acid to 230 g of copper anode mud, mix the mixture, heat it to 650°C in a muffle furnace and keep it warm for 3 hours, and obtain mature slag after aging. After the volatilized selenium dioxide gas is absorbed by water during the aging process, a first solution is obtained, and sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain the first filter residue; the leaching solid-liquid ratio is 1:4; (2) Add 1200 ml of 4 mol / L hydrochloric acid solution to the first filter residue, the liquid-to-solid ratio of the hydrochloric acid solution to the first filter residue is 5:1, and heat to a constant temperature of 50°C, introduce chlorine gas and control the dissolution potential of the solution to 1030 mv, selectively dissolve the gold in the solution for 2 hours, and filter to obtain tellurium-rich residue and chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, and the second filter residue is activated and filtered to obtain a third filter residue and an activation solution; the activation treatment comprises the following steps: adding the second filter residue to 100 ml of pure water, heating to 40°C and dripping 4.5 ml of hydrazine hydrochloride solution to react for 3 hours for activation treatment, the mass ratio of the reducing agent hydrazine hydrochloride solution to the second filter residue is 0.08:1, filtering to obtain an activated third filter residue and an activation solution, the liquid-to-solid ratio of the second filter residue to the activation solution is 3:1, and the activation solution is sent to the wastewater treatment section; (4). Heat the chloroauric acid solution to 50°C to remove chlorine for 1.5 hours, then stop heating. Then add the third filter residue to the chloroauric acid solution, control the redox potential of the solution to drop to 790mv-840mv, and then replace the gold until the gold in the solution is completely replaced. Filter to obtain crude gold powder and tellurium chloride filtrate; electrolyze and purify the crude gold powder to obtain gold powder containing 99.98% gold, with a gold yield of 98.77%; neutralize the tellurium chloride filtrate with a 20% sodium hydroxide solution to a pH of 5 and precipitate it into tellurium oxide. Adjust the pH of the tellurium oxide precipitate to 14 with a 15% sodium hydroxide solution, dissolve the tellurium oxide into sodium tellurate solution, and then send it to the electrolysis section for electrolysis to obtain metallic tellurium.

[0023] Example 3

[0024] This embodiment provides a method for enriching and recovering gold from copper anode mud, which specifically includes the following steps: (1) Add 166 ml of concentrated sulfuric acid to 170 g of copper anode mud, mix the mixture, heat it to 350°C in a muffle furnace and keep it warm for 2 hours, and obtain mature slag after aging. After the volatilized selenium dioxide gas is absorbed by water during the aging process, a first solution is obtained, and sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain the first filter residue; the leaching solid-liquid ratio is 1:5; (2) Add 1000 ml of 3 mol / L hydrochloric acid solution to the first filter residue, the liquid-to-solid ratio of the hydrochloric acid solution to the first filter residue is 5:1, and heat to 83°C and keep constant temperature, introduce chlorine gas and control the solution dissolution potential to 767 mv, selectively dissolve the gold in the solution for 2 hours, and filter to obtain tellurium-rich residue and chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, and the second filter residue is activated and filtered to obtain a third filter residue and an activation solution; the activation treatment comprises the following steps: adding the second filter residue to 300 ml of pure water, heating to 60° C. and dripping 6 ml of potassium borohydride solution to react for 1.5 hours for activation treatment, wherein the mass ratio of the reducing agent potassium borohydride solution to the second filter residue is 0.1:1, filtering to obtain an activated third filter residue and an activation solution, wherein the liquid-to-solid ratio of the second filter residue to the activation solution is 1.5:1, and the activation solution is sent to the wastewater treatment section; (4). Heat the chloroauric acid solution to 70℃ to remove chlorine for 0.8h and then stop heating. Then add the third filter residue to the chloroauric acid solution, control the redox potential of the solution to drop to 700mv-750mv, and then replace the gold until the gold in the solution is completely replaced. Filter to obtain crude gold powder and tellurium chloride filtrate; electrolyze and purify the crude gold powder to obtain gold powder containing 99.98% gold, with a gold yield of 97.97%; neutralize the tellurium chloride filtrate with a mass fraction of 30% sodium hydroxide solution to a pH of 5 and precipitate it into tellurium oxide. Adjust the pH of the tellurium oxide precipitate to 14 with a mass fraction of 10% sodium hydroxide solution, dissolve the tellurium oxide into sodium tellurate solution, and then send it to the electrolysis section for electrolysis to obtain metallic tellurium.

[0025] Example 4

[0026] This embodiment provides a method for enriching and recovering gold from copper anode mud, which specifically includes the following steps: (1) Add 99 ml of concentrated sulfuric acid to 55 g of copper anode mud, mix the mixture, heat it to 230°C in a muffle furnace and keep it warm for 4.5 hours, and obtain mature slag after aging. After the selenium dioxide gas volatilized during the aging process is absorbed by water, a first solution is obtained, sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain the first filter residue; the leaching solid-liquid ratio is 1:5; (2) Add 60 ml of 6 mol / L hydrochloric acid solution to the first filter residue, the liquid-to-solid ratio of the hydrochloric acid solution to the first filter residue is 8:1, and heat to 83°C and keep constant temperature, introduce chlorine gas to control the dissolution potential of the solution to 1050 mv, selectively dissolve the gold in the solution for 0.5 h, and filter to obtain tellurium-rich residue and chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, and the second filter residue is activated and filtered to obtain a third filter residue and an activation solution; the activation treatment comprises the following steps: adding the second filter residue to 50 ml of pure water, heating to 83° C. and dripping 1.5 ml of ascorbic acid solution to react for 2 hours for activation treatment, wherein the mass ratio of the reducing agent ascorbic acid solution to the second filter residue is 0.05:1, filtering to obtain an activated third filter residue and an activation solution, wherein the liquid-to-solid ratio of the second filter residue to the activation solution is 2:1, and the activation solution is sent to the wastewater treatment section; (4). Heat the chloroauric acid solution to 90℃ to drive out the chlorine for 1 hour and then stop heating. Then add the third filter residue to the chloroauric acid solution, control the redox potential of the solution to drop to 580mv-630mv, and then replace the gold until the gold in the solution is completely replaced. Filter to obtain crude gold powder and tellurium chloride filtrate; electrolyze the crude gold powder to obtain gold powder containing 99.95% gold and a gold yield of 96.61%; neutralize the tellurium chloride filtrate with a mass fraction of 25% sodium hydroxide solution to a pH of 5 and precipitate it into tellurium oxide. Adjust the pH of the tellurium oxide precipitate to 14 with a mass fraction of 12% sodium hydroxide solution, dissolve the tellurium oxide into sodium tellurate solution, and then send it to the electrolysis section for electrolysis to obtain metallic tellurium.

[0027] Example 5

[0028] This embodiment provides a method for enriching and recovering gold from copper anode mud, which specifically includes the following steps: (1) Add 1200 ml of concentrated sulfuric acid to 1000 g of copper anode mud, mix the mixture, heat it to 730°C in a muffle furnace and keep it warm for 1.5 hours, and obtain mature slag after aging. After the volatilized selenium dioxide gas is absorbed by water during the aging process, a first solution is obtained, and sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain the first filter residue; the leaching solid-liquid ratio is 1:5; (2) Add 2000 ml of 5 mol / L hydrochloric acid solution to the first filter residue, the liquid-to-solid ratio of the hydrochloric acid solution to the first filter residue is 7:1, and heat to 84°C at a constant temperature, introduce chlorine gas to control the dissolution potential of the solution to 730 mv, selectively dissolve the gold in the solution for 2 hours, and filter to obtain tellurium-rich residue and chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, and the second filter residue is activated and filtered to obtain a third filter residue and an activation solution; the activation treatment comprises the following steps: adding the second filter residue to 500 ml of pure water, heating to 85°C and dropwise adding 150 ml of hydrazine hydrate and 20 ml of potassium borohydride solution to react for 4 hours for activation treatment, wherein the mass ratio of the reducing agent (hydrazine hydrate and potassium borohydride solution) to the second filter residue is 0.02:1, filtering to obtain an activated third filter residue and an activation solution, wherein the liquid-to-solid ratio of the second filter residue to the activation solution is 2.5:1, and the activation solution is sent to the wastewater treatment section; (4) The chloroauric acid solution is heated to 110°C to remove chlorine for 1.3 hours and then the heating is stopped. The third filter residue is then added to the chloroauric acid solution. The redox potential of the solution is controlled to drop to 740mv-800mv and then gold is replaced until the gold in the solution is completely replaced. The crude gold powder and tellurium chloride filtrate are obtained by filtration. The crude gold powder is electrolytically purified to obtain gold powder containing 99.99% gold and a gold yield of 99.61%. The tellurium chloride filtrate is neutralized with a 40% sodium hydroxide solution by mass to a pH of 5 and then precipitated into tellurium oxide. The tellurium oxide precipitate is then adjusted to a pH of 14 with a 15% sodium hydroxide solution by mass. The tellurium oxide is dissolved into a sodium tellurate solution and then sent to the electrolysis section for electrolysis to obtain metallic tellurium.

[0029] The preferred embodiments of the present invention are described above with reference to the accompanying drawings. A person skilled in the art may implement the present invention in a variety of variations without departing from the scope and essence of the present invention. For example, a feature shown or described as part of one embodiment may be used in another embodiment to obtain another embodiment. The above are only preferred feasible embodiments of the present invention, and do not limit the scope of rights of the present invention. Any equivalent changes made using the contents of the present specification and the accompanying drawings are included in the scope of rights of the present invention.

Claims

1. A method for enriching and recovering gold from copper anode mud, characterized in that: The specific steps include: (1) Add a preset amount of concentrated sulfuric acid to the copper anode mud and mix and mature for a preset time to obtain a mature slag. After the volatilized gas is absorbed by water during the maturation process, a first solution is obtained. Sulfur dioxide gas is introduced into the first solution to obtain primary selenium; water is added to the mature slag to dissolve the copper sulfate in the mature slag in the water, and the copper is separated by filtration to obtain a first filter residue; (2) After adding a preset amount of hydrochloric acid solution to the first filter residue and heating it to a preset temperature, chlorine gas is introduced to control the dissolution potential of the solution, and the gold in the solution is selectively dissolved and treated to make a liquid, and then filtered to obtain a tellurium-rich residue and a chloroauric acid solution; (3) After the tellurium-rich residue is pre-treated by flotation to remove silver, a second filter residue is obtained, the second filter residue is activated, and the third filter residue and activation solution are obtained by filtration; (4) After heating the chloroauric acid solution to remove the chlorine, the heating is stopped, and then the third filter residue is added to the chloroauric acid solution. The redox potential of the solution is controlled to drop to a preset range, and then the gold is replaced until the gold in the solution is completely replaced. The crude gold powder and tellurium chloride filtrate are obtained by filtration. The crude gold powder is purified to obtain metallic gold; The tellurium chloride filtrate is converted into tellurium oxide by neutralization and precipitation with alkaline solution, and then dissolved into sodium tellurate solution with alkali and sent to the electrolysis section for electrolysis to obtain metallic tellurium.

2. The method for enriching and recovering gold from copper anode mud according to claim 1, characterized in that: The liquid-solid ratio of concentrated sulfuric acid to copper anode mud is 0.4-1.8:1, the aging temperature is 200℃-730℃, the aging time is 1.5h-4.5h, and the leaching solid-liquid ratio is 1:3-5.

3. The method for enriching and recovering gold from copper anode mud according to claim 1, characterized in that: In step (2), the concentration of the hydrochloric acid solution is 1 mol / L-6 mol / L, the liquid-solid ratio of the hydrochloric acid solution to the first filter residue is 3-8:1, the heating temperature is 50-90°C, and the dissolution potential is 730mv-1050mv.

4. The method for enriching and recovering gold from copper anode mud according to claim 1, characterized in that: In step (3), the activation treatment comprises the following steps: adding the second filter residue into pure water, heating and adding a preset amount of reducing agent for activation treatment, filtering to obtain an activated third filter residue and an activation liquid, and sending the activation liquid to a wastewater treatment section; wherein the liquid-to-solid ratio of the second filter residue to the activation liquid is 1-3:1; the reduction temperature is 40°C-90°C; the mass ratio of the reducing agent to the second filter residue is 0.01-0.1:1, and the reduction time is 0.5h-4h.

5. The method for enriching and recovering gold from copper anode mud according to claim 4, characterized in that: The reducing agent is one or more of ascorbic acid, hydrazine hydrochloride, potassium borohydride and hydrazine hydrate mixed in any ratio.

6. The method for enriching and recovering gold from copper anode mud according to claim 1, characterized in that: In the step (4), the chlorine removal temperature is 50°C-110°C, and the chlorine removal time is 0.5h-1.5h; during the replacement process, the solution redox potential is 550mv-840mv.

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