A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud

Abstract

The present invention discloses a valuable metal recovery process for copper anode mud leaching based on Fenton reagent oxidation, belonging to the technical field of non-ferrous metal smelting, comprising the following steps: (1) subjecting pretreated anode mud to advanced oxidation leaching, and obtaining a first leachate and a first gold-rich leach residue after leaching; (2) adding chloride to the first leachate, and obtaining a second leachate and a second silver-rich leach residue after precipitation and filtration; (3) recovering a third leachate and refined silver; and (4) recovering the third leachate by electrowinning to obtain refined copper. In the present invention, different valuable elements undergo liquid / solid selective separation, complexation, reduction, and leachate treatment, and have the advantages of high recycling rate, high valuable element leaching rate and recovery rate, high environmental protection standards, high leaching efficiency, high input-output ratio, and high process adjustability, thereby being a green leaching process.

Description

Technical Field

[0001] The present invention relates to the field of nonferrous metal smelting, and in particular to a valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud. Background Art

[0002] Anode slime is formed during the electrolytic refining process of blister copper into refined copper. As copper is continuously precipitated at the anode, metals with higher potentials than copper and insoluble materials deposit near the anode, forming anode slime. The yield of copper anode slime is generally 0.2-0.8%, sometimes as high as 1.5%. Its main elemental percentages are Cu (10-25%), Ag (5-53%), Au (0.05-5%), Se (2-24%), Ni (0.1-45%), Bi (0.9-7%), Pb (0.5-12%), Sb (0.2-30%), and S (2-10%). Compared to copper ore, anode slime has a higher enrichment rate of valuable metals and a more cost-effective output / recovery ratio. Non-metallic elements form highly stable compounds with metallic elements, primarily chalcogens (O, S, Se, and Te), which form highly stable and insoluble compounds with Cu and Ag. This makes recovery of valuable metals from anode slime difficult.

[0003] Currently, the recovery of valuable metals from anode slime primarily relies on pressurized acid leaching. For example, copper is removed from anode slime under pressure. Another example is oxygen-enriched pressure leaching at 160°C and 1.2 MPa. Existing technology for tellurium recovery in high-pressure equipment has achieved a tellurium recovery rate approaching 90%. However, during pressurized acid leaching, a physical method for enhancing leaching, some insoluble copper and silver compounds remain unleached, and the required sulfuric acid concentration is also very high. To address these issues, existing technology has employed microwave pressure leaching to increase the leaching rate, but this method is not suitable for processing large quantities of anode slime. Other methods include pre-treating anode slime using sulfuric acid heating leaching, but this method fails to leach some of the more stable Ag2S and Ag2Se, resulting in accumulation in the leached residue. This, in turn, still results in pollutant emissions during the smelting of the metal-enriched slag.

[0004] Current anode processing techniques include pyrometallurgy, roasting-wet metallurgy, and fully wet metallurgy. Pyrometallurgy utilizes smelting processes to reduce and recover valuable elements, while roasting-wet metallurgy recovers valuable elements through leaching and reduction. Sulfate roasting requires flue gas treatment equipment on the production line, which is energy-intensive and limited to temperature control, a single control method. Furthermore, the flue gas generated can pollute the environment and is inconsistent with the concept of green production. Fully wet metallurgy offers high adaptability. Wet acid leaching can effectively and selectively leach and reduce insoluble substances in anode mud, facilitating the selective recovery of different valuable elements. Wet metallurgy offers advantages such as high efficiency, short production cycles, low energy consumption, and adjustable process steps. Its primary method involves removing base metals and enriching precious metals. Valuable elements are converted to ions through oxidation. Selective solid-liquid separation of different valuable elements is achieved through the addition of chelating agents. The desired valuable elements are then recovered through the addition of reducing agents or electrolysis.

[0005] In existing technologies, wet acid leaching uses physical assistance / oxidants + sulfuric acid for leaching. Physical assistance includes methods such as ultrasound, microwaves, heating, and pressurization to enhance leaching efficiency, but some compounds with high oxidation potentials are difficult to leach. The addition of oxidants can increase the oxidation potential of the leaching reaction, thereby effectively leaching insoluble compounds, significantly improving leaching rate and efficiency. Common oxidants include MnO2, O3, and HNO3, but their use can introduce other ions or cause air pollution.

[0006] Therefore, how to provide an anode slime treatment process with low environmental pollution, high recovery rate of valuable metals and high leaching efficiency is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] The purpose of the present invention is to provide a valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud to solve the problems existing in the above-mentioned prior art.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud comprises the following steps:

[0010] (1) Add quantitative Fe to the pretreated anode mud 0 The powder is continuously stirred in a mixture of sulfuric acid and hydrogen peroxide is quantitatively introduced to perform advanced oxidation leaching. After the leaching is completed, a first leachate and a first gold-rich leaching residue are obtained;

[0011] (2) adding chloride to the first leachate, and obtaining a second leachate and a second silver-rich leach residue after precipitation and filtration;

[0012] (3) adding sulfite to the second leachate to obtain selenium, tellurium products and a third leachate after reaction; adding sodium thiosulfate to the second silver-rich leach residue to complex silver, and electrolytically recovering refined silver, and the liquid after electrolytic recovery is reused to complex the second silver-rich leach residue;

[0013] (4) Recovering the third leaching solution through electrowinning to obtain refined copper.

[0014] The Fenton reagent of the present invention adopts Fe 0 Powder reacts with sulfuric acid to produce Fe 2+ (FeSO4 exists in the solution) to promote the decomposition of H2O2 to produce hydroxyl radicals (OH·) with high oxidation potential. In actual process, Fe is added to sulfuric acid. 0 Powder, and then quantitatively introduce hydrogen peroxide.

[0015] Beneficial effect: The present invention adopts advanced oxidation method to leach anode mud, specifically using Fenton reagent (Fe 0 Powder and H2O2) and sulfuric acid are used to leach the anode mud. The specific implementation process is to add a quantitative amount of Fe 0 The powder and sulfuric acid mixture are continuously stirred, and hydrogen peroxide is quantitatively introduced, wherein the Fenton reagent as an oxidant has the characteristics of being green, high potential, high leaching rate and short time consumption. Relative to other oxidants, the Fenton reagent in the present invention has a high oxidizing ability, can reduce the concentration of sulfuric acid and reduce acid consumption. In the present invention, different valuable elements are subjected to liquid / solid separation, complexation, reduction, and leachate treatment, and have the characteristics of high recycling rate, high leaching rate and recovery rate of valuable elements, high environmental protection standards, high leaching efficiency, high input-output ratio, high process adjustability, etc., which is a green leaching process.

[0016] Preferably, the anode mud in step (1) is copper smelting anode mud.

[0017] The pretreatment comprises drying the anode mud at 60-100° C. for 12-24 hours, crushing the anode mud, grinding the anode mud at 150-400 rpm for 0.5-1.5 hours, and then passing the anode mud through a 5-320 mesh sieve to obtain the pretreated anode mud.

[0018] Beneficial effects: The above drying process can volatilize the moisture in the anode mud. The dried anode mud will stick together into blocks and be crushed to a certain particle size, which makes it easier for the grinding equipment to grind it into finer particles more quickly. After drying, crushing, grinding and screening, the anode mud with a mesh size greater than 60 (that is, the anode mud with a particle size less than 0.300mm is used for experiments). The mass proportion of anode mud with a particle size less than 0.300mm can reach more than 85%, and the difference in particle size is very small, so as to achieve a uniform chemical reaction during the leaching process and reduce the experimental error caused by large differences in particle size. Particles larger than 0.300mm can be crushed, ground, screened and reused.

[0019] Preferably, the stirring rate in step (1) is 150-600 rpm, the leaching temperature is 25-65° C., and the leaching time is 20-150 min.

[0020] Beneficial effects: The anode mud in the present invention has a high density and is very easy to precipitate in the solution. Stirring can keep the anode mud in a suspended state during the reaction process, accelerating the chemical reaction. Increasing the reaction temperature can reduce the activation energy required for the reaction, but too high a temperature can easily decompose H2O2, resulting in low leaching.

[0021] Preferably, the solid-liquid ratio of the pretreated anode mud to the mixed solution in step (1) is 1 g: (6-10) mL.

[0022] The sulfuric acid concentration is 0.5-2.5 mol / L;

[0023] The percentage concentration of the hydrogen peroxide is 30%;

[0024] The Fe 0 The molar ratio of the powder to the H2O2 in hydrogen peroxide is 1:(3-6).

[0025] Beneficial effect: The present invention limits the amount of hydrogen peroxide introduced per unit time to Fe 0 Powder forms a fixed ratio, Fe 0 Powder in sulfuric acid H + Converted into Fe 2+ , promoting the optimal catalytic ability of hydrogen peroxide to produce hydroxyl radicals (OH·) per unit time, while making up for Fe 3+ Fe 2+ The problem of slow conversion rate is as follows:

[0026] Fe+2H + →Fe 2+ +H2↑

[0027] Fe 2+ +H2O2→Fe 3+ +OH- +OH·

[0028] Fe 3+ +H2O2→Fe 2+ +H + +HO2

[0029] Fe 3+ +HO2·→Fe 2+ +H + +O2↑

[0030] 2Fe 3+ +Fe→3Fe 2+

[0031] Preferably, the chloride in step (2) is Cl - The molar mass ratio of silver to anode mud is (1.5-2):1;

[0032] The chloride includes one or more of HCl, NaCl and KCl.

[0033] Beneficial effect: The present invention introduces chloride in step (2), which can remove Ag in the first leachate. + It is converted into AgCl precipitate and enriched in the second silver-rich slag.

[0034] Preferably, step (2) further comprises recovering gold using the first gold-rich leaching residue, which specifically comprises the following steps:

[0035] (2-1) adding chlorate and hydrochloric acid to the first gold-rich leaching residue for leaching, filtering after leaching is completed, and collecting the filtrate and filter residue;

[0036] (2-2) adding oxalic acid (H2C2O4), active metal reduced gold or electrodeposited reduced gold to the filtrate;

[0037] The gold in step (2-1) and ClO3 in chlorate - The molar ratio of gold to hydrochloric acid is 1: (1-2), and the chlorate includes KClO3 and NaClO3; the molar ratio of gold to hydrochloric acid is 1: (2-4)

[0038] The reduction in step (2-2) includes electrolytic reduction or oxalic acid reduction;

[0039] In the electrolytic reduction, the anode is a graphite electrode and the cathode is gold;

[0040] In the oxalic acid reduction, the molar ratio of gold to oxalic acid is 1:(1-2);

[0041] Beneficial effect: Anode mud in ClO3 - , the following reaction will occur under the action of HCl:

[0042] 2NaClO3+4HCl=2NaCl+Cl2+2ClO2+2H2O

[0043] 2Au+2HCl+3Cl2=2HAuCl4

[0044] The process of oxalic acid reduction is as follows:

[0045] 2HAuCl4+2H2C2O4=2Au+8HCl+6CO2

[0046] Electrolytic reduction:

[0047] Cathode: HAuCl4+3e - =Au+HCl+3Cl -

[0048] Anode: H + -2e - =H2↑

[0049] Preferably, step (3) includes reducing selenium and tellurium in the second leachate and recovering silver from the second silver-rich leaching residue, specifically comprising the following steps:

[0050] (3-1) introducing sulfite into the second leachate to reduce selenium and tellurium, wherein the ratio of the sulfite to the total molar mass of selenium and tellurium in the anode mud is (2-4):1. After the reduction is completed, collecting the copper-rich filtrate and the selenium- and tellurium-rich filter residue;

[0051] The sulfite-containing substances include H2SO3, Na2SO3, and K2SO3;

[0052] (3-2) adding thiosulfate to the second silver-rich leaching residue to complex the silver, wherein the molar mass ratio of the sodium thiosulfate to the silver element in the anode mud is (2-3):1, and then recovering the silver by electrolytic reduction.

[0053] The thiosulfate includes Na2S2O3 and K2S2O3;

[0054] In the electrowinning recovery, the anode is a graphite electrode and the cathode is silver.

[0055] Beneficial effects: SeO3 - 、SeO4 - 、TeO4 - Reduced by Na2SO3, the acid radical in the solution is still SO4 2- Mainly, no new acid radical will be introduced. The relevant reaction equation is as follows:

[0056] Na2SO3+H2SeO4=Na2SO4+H2SeO3

[0057] 2Na2SO3+H2SeO3=Se↓+Na2SO4+H2O

[0058] 3Na2SO3+H2TeO4=Te↓+3Na2SO4+H2O

[0059] Thiosulfate can spontaneously complex with AgCl, and the complexed Ag(S2O3) 3- It can achieve a high Ag electrowinning recovery rate and still have a high AgCl complexing ability after electrowinning. The specific reactions involved are as follows:

[0060] Complexation reaction:

[0061] AgCl+2S2O3 2- =Ag(S2O3) 3- +Cl -

[0062] Electrolytic reduction:

[0063] Cathode: 2Ag(S2O3) 3- +2e - =2Ag↓+4S2O3 2-

[0064] Anode: 2H + -2e - =H2↑

[0065] Preferably, in the electrolytic recovery in step (4), the anode is a graphite electrode, the cathode is a copper electrode, and the electrolyte is the third leaching solution.

[0066] Beneficial effect: The main phase enriched in the third leachate is CuSO4. High-purity copper can be obtained by reducing copper by electrowinning. The main reactions involved are as follows:

[0067] Cathode: Cu 2+ +2e - =Cu↓

[0068] Anode: 2H + -2e - =H2↑

[0069] Preferably, after the electrolytic recovery in step (4), the electrolyte is collected, NaOH is added thereto, and the pH is adjusted to ≥ 4 to obtain Fe(OH)3 precipitate;

[0070] or,

[0071] Collect the electrolyte and add Fe 0 Powder reduced Fe 3+ , get Fe 2+ solution. Fe2+ The solution can be combined with hydrogen peroxide to form a new Fenton reagent for advanced oxidation leaching of the pretreated anode mud.

[0072] Beneficial effect: The divalent iron solution obtained by the reduction of iron powder can promote hydrogen peroxide to generate a high potential (OH·, 2.80 eV), thereby constructing a new Fenton reagent and achieving the effect of resource recycling.

[0073] The present invention discloses a valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud. The present invention aims at the selective separation and selective recovery of different valuable elements in anode mud. The recovery paths of various valuable elements cooperate with each other and are independent of each other. The entire process involves the recovery of many types of valuable elements, the process flow is flexible to adjust, the adaptability to working conditions is strong, and the operation process is safe and harmless. The present invention can maximize the value of the entire green process of wet leaching of anode mud and recovery of valuable elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0075] Figure 1 This is a flow chart of a valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to Example 1 of the present invention. DETAILED DESCRIPTION

[0076] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0077] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0078] The anode mud used in the embodiments of the present invention comes from a copper company in Yunnan.

[0079] Example 1

[0080] A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud comprises the following steps:

[0081] (1) The collected nonferrous metallurgical anode slime was dried at 80°C for 18 hours, crushed in a crusher, and ground in a planetary ball mill at 200 rpm for 90 minutes. The anode slime was sieved for 15 minutes on a 6-grade vibrating screen (5 mesh, 20 mesh, 60 mesh, 100 mesh, 200 mesh, and 320 mesh). Anode slime with a sieve size greater than 60 mesh (i.e., a particle size less than 0.300 mm) was used for advanced oxidation leaching. The mass of anode slime with a particle size less than 0.300 mm accounted for more than 85% of the total sieved anode slime. The particle size difference of anode slime within this range was extremely small, and the chemical reaction and mass transfer were uniform.

[0082] (2) The percentage of the main elements in the pre-treated anode mud is estimated by using detection equipment, which has a guiding significance for the use of reagents in the entire wet leaching process. After testing, the content of the main valuable elements is shown in Table 1:

[0083] Table 1

[0084] element Copper (Cu) Selenium (Se) Tellurium (Te) Silver (Ag) Gold (Au) Other ingredients content 5.512％ 5.921％ 3.858％ 6.815％ 0.0694％ 77.8246％

[0085] (3) The reaction vessel is a 500ml flask. 50.00g of anode mud is added to 300ml of sulfuric acid at a concentration of 1.5mol / L. The solid / liquid ratio of anode mud to sulfuric acid is 1:6 (g / ml). The temperature is controlled at 60℃ and the stirring speed is 300rpm. 0.2molFe 0 Powder, 0.6 mol H2O2 (equivalent to 68 ml of 30% hydrogen peroxide), hydrogen peroxide is introduced by a peristaltic pump for 120 minutes. After filtration and separation, the first leachate (copper, silver, selenium, and tellurium leachate) and the first gold-rich leach residue are obtained;

[0086] (4) In the first leaching solution, the Ag and Cl in the anode mud are separated. - NaCl was added at a molar ratio of 1:1.5 to convert Ag into AgCl precipitate, which was filtered and washed using a Buchner funnel at a pressure of -0.04 MPa to obtain a second leachate (copper, selenium, and tellurium leachate) and a second silver-rich leachate residue;

[0087] (5) For the first gold-rich leaching residue, NaClO3+HCl is used to leach gold, and then oxalic acid (H2C2O4) is used to reduce HAuCl4.

[0088] (5-1) Gold leaching: According to the gold and ClO3 - NaClO3 and HCl are introduced into the gold-rich leaching residue from the first leaching at a molar ratio of 1:2 and a molar ratio of HCl of 1:4 to leach gold and obtain HAuCl4;

[0089] (5-2) Recovery of gold from HAuCl4: HAuCl4 was reduced using oxalic acid (H2C2O4) with a mass ratio of gold to oxalic acid of 1:2.

[0090] (6) The second leachate is rich in copper ions, selenate, tellurate, etc. Na2SO3 is added to the leachate according to the total molar amount of Se and Te in the anode mud and the molar amount of sulfite at a ratio of 1:3 to reduce and precipitate selenium and tellurium to form selenium and tellurium products with economic value. The third leachate (rich in Cu) is then filtered. 2+ CuSO4 solution);

[0091] (7) Recovery of silver from the second silver-rich slag: Sodium thiosulfate is used to complex the silver in the silver-rich slag, wherein the molar ratio of silver to sodium thiosulfate is 1:1.5 to complex Ag to form Ag(S2O3). 3- The complexing liquid uses a constant voltage of -0.7V to electrolytically recover silver, wherein a graphite electrode is used as the anode and silver is used as the cathode. Silver can be enriched, purified and precipitated at the cathode. After the electrolysis is completed, the silver electrolytic liquid is circulated and used as a complexing agent for silver in the silver-rich slag.

[0092] (8) The third leaching solution was used as the electrolyte, a graphite electrode was used as the anode, and a copper electrode was used as the cathode. Electrolytic recovery was performed at a constant voltage of -0.4 V, and refined copper was deposited at the cathode.

[0093] (9) Fe in the solution after step (8) electrolysis 3+ Recovery: After the electrolysis is completed in step (8), the electrolysis solution obtained is rich in Fe 3+ , add 0.5 times the molar mass of Fe 0 Fe 3+ Converted to Fe 2+ , which can form new ferrous sulfate, Fe 2+ It can further promote the decomposition of hydrogen peroxide to produce OH·, and carry out advanced oxidation leaching of anode mud.

[0094] After testing, the final recovery rates of copper, selenium, tellurium, silver, and gold were 99.5%, 98.0%, 92.0%, 99.5%, and 99.5%, respectively. The ferrous sulfate solution in the post-copper electrolytic solution still had over 90% of its ability to catalyze hydrogen peroxide (calculated based on the generation of high-potential free radicals). The post-silver electrolytic solution still had over 95% of its ability to complex silver ions (calculated based on the amount of complexed silver).

[0095] Example 2

[0096] A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud, which differs from Example 1 only in that:

[0097] The recovery of gold in step (5-2) includes the following steps: (5-2) reduction and recovery of gold in the gold-rich solution: an electrolytic reduction process is adopted, a graphite electrode is used as the anode, and gold is used as the cathode, and gold is purified and precipitated at the cathode under a constant voltage of -1.40V.

[0098] After testing, the final recovery rates of copper, selenium, tellurium, silver, and gold were 99.5%, 98.0%, 92.0%, 99.5%, and 99.0%, respectively. The ferrous sulfate solution in the post-copper electrowinning solution still had over 90% of its ability to catalyze hydrogen peroxide (calculated based on the generation of high-potential free radicals). The post-silver electrowinning solution still had over 95% of its ability to complex silver ions (calculated based on the amount of complexed silver).

[0099] Example 3

[0100] A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud is different from Example 1 only in that step (8) includes the following steps:

[0101] Step (8) Fe in the solution after electrolysis 3+ Recovery: Add NaOH to the electrolytic solution obtained after the electrolysis in step (8) to adjust the pH of the solution to ≥4, so that the Fe 3+ All elements Fe(OH)3 are precipitated.

[0102] After testing, the final recovery rates of copper, selenium, tellurium, silver and gold were 99.5%, 98.0%, 92.0%, 99.5% and 99.5% respectively. Fe(OH)3 can be used as Fe-containing chemicals, and the post-electrolytic silver solution still has the ability to complex silver ions by more than 95% (calculated based on the amount of complexed silver).

[0103] Comparative Example 1

[0104] A process for recovering valuable metals from anode mud, which differs from Example 1 only in that:

[0105] No Fe is added in step (3) 0 The remaining steps and parameters are the same as those in Example 1.

[0106] Testing revealed that the final recovery rates for copper, selenium, tellurium, silver, and gold were 95%, 98.0%, 51.0%, and 48.0%, respectively. The ferrous sulfate solution in the post-copper electrolytic solution still possessed over 93% of the ability to promote hydrogen peroxide to generate OH· for advanced oxidation of anode mud (calculated based on the generation of high-potential free radicals). The post-silver electrolytic solution still possessed over 95% of the ability to complex silver ions (calculated based on the amount of complexed silver).

[0107] Comparative Examples 2-3

[0108] A process for recovering valuable metals from anode mud, which differs from Example 1 only in that:

[0109] Fe in step (3) 0 The molar ratio of powder to H2O2 is 1:6. The remaining steps and parameters are the same as those in Example 1.

[0110] After testing, the final recovery rates of copper, selenium, tellurium, silver and gold were 99.5%, 98.5%, 93.0%, 99.5% and 99.5% respectively. The ferrous sulfate solution in the copper electrowinning solution still has more than 92% of the ability to promote hydrogen peroxide to produce OH and perform advanced oxidation of anode mud (calculated based on the generation of high potential free radicals). At the same time, the unreacted Fe 0 The post-electrolytic silver solution still has the ability to complex silver ions by more than 95% (calculated based on the amount of complexed silver).

[0111] Comparative Example 4

[0112] A process for recovering valuable metals from anode mud, which differs from Example 1 only in that:

[0113] Fe is not used in step (3) 0 powder and hydrogen peroxide, specifically comprising the following steps:

[0114] In the reaction tank, anode mud was added to 1.5 mol / L sulfuric acid, where the solid-liquid ratio of anode mud to sulfuric acid was 1:6 (g / ml). The temperature was controlled at 60°C and the stirring speed was 300 rpm. The remaining steps and parameters were the same as in Example 1.

[0115] After testing, the final recovery rates of copper, selenium, tellurium, silver and gold were 33.0%, 0.4%, 23.2%, 15.0% and 99.5% respectively. The rear liquid of electrolytic silver still has the ability of complexing silver ions of 95% (calculated based on the amount of complexed silver).

[0116] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud, characterized in that: The following steps are involved: (1) Add the pretreated anode mud to the Fe 0 The mixture of the powder and sulfuric acid is continuously stirred, and hydrogen peroxide is quantitatively introduced to perform advanced oxidation leaching, and after the leaching is completed, a first leachate and a first gold-rich leaching residue are obtained; The Fe 0 The molar ratio of the powder to H2O2 in hydrogen peroxide is 1: (3-6); (2) adding chloride to the first leachate, and obtaining a second leachate and a second silver-rich leach residue after precipitation and filtration; (3) adding sulfite to the second leachate to obtain selenium, tellurium products and a third leachate after a reduction reaction; adding sodium thiosulfate to the second silver-rich leach residue to complex silver, and recovering it by electrowinning to obtain refined silver, and the liquid after electrowinning is reused to complex the second silver-rich leach residue; (4) Recovering the third leaching solution by electrowinning to obtain refined copper.

2. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: The anode mud in step (1) is copper smelting anode mud; The pretreatment comprises drying the anode mud at 60-100° C. for 12-24 hours, crushing the anode mud, grinding the anode mud at 150-400 rpm for 0.5-1.5 hours, and then passing the anode mud through a 5-320 mesh sieve to obtain the pretreated anode mud.

3. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: In step (1), the stirring rate is 150-600 rpm, the leaching temperature is 25-65° C., and the leaching time is 20-150 min.

4. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: The solid-liquid ratio of the pretreated anode mud to the mixed liquid in step (1) is 1 g: (6-10) mL; The sulfuric acid concentration is 0.5-2.5 mol / L; The concentration of the hydrogen peroxide is 30%.

5. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: Cl in the chloride in step (2) - The molar mass ratio of silver to anode mud is (1.5-2):1; The chloride includes one or more of HCl, NaCl and KCl.

6. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: Step (2) also includes recovering gold using the first gold-rich leaching residue, which specifically includes the following steps: (2-1) adding chlorate and hydrochloric acid to the first gold-rich leaching residue for leaching, filtering after leaching is completed, and collecting the filtrate and filter residue; (2-2) The filtrate is added to oxalic acid reduced gold, active metal reduced gold or electrolytic reduced gold.

7. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 6, characterized in that: In step (2-1), gold reacts with ClO3 in chlorate - The molar ratio is 1: (1-2), and the chlorate includes KClO3 and NaClO3; The molar ratio of gold to hydrochloric acid is 1: (2-4); In the electrolytic reduction of gold in step (2-2), the anode is a graphite electrode and the cathode is gold; In the oxalic acid-reduced gold, the molar ratio of gold to oxalic acid is 1:(1-2).

8. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: Step (3) includes reducing selenium and tellurium in the second leaching solution and recovering silver from the second silver-rich leaching residue, and specifically includes the following steps: (3-1) introducing sulfite into the second leachate to reduce selenium and tellurium, wherein the molar mass ratio of the sulfite to the total molar mass of selenium and tellurium in the anode mud is (2-4):1, and collecting the copper-rich filtrate and the selenium- and tellurium-rich filter residue after the reduction is completed; Sulfite-containing substances include H2SO3, Na2SO3, and K2SO3; (3-2) Sodium thiosulfate is added to the second silver-rich leaching residue to complex the silver, wherein the molar mass ratio of the sodium thiosulfate to the silver element in the anode mud is (2-3):1, and then the silver is recovered by electrolytic reduction. In the electrolytic reduction of silver, the anode is a graphite electrode and the cathode is silver.

9. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: In the electrolytic recovery described in step (4), the anode is a graphite electrode, the cathode is a copper electrode, and the electrolyte is the third leaching solution.

10. The valuable metal recovery process based on Fenton reagent oxidation leaching of copper anode mud according to claim 1, characterized in that: After the electrolytic recovery in step (4), the electrolytic solution is collected, and NaOH is added thereto to adjust the pH of the electrolytic solution to ≥ 4, so that the iron element therein forms Fe(OH)3 precipitation; or, Collect the liquid after electrolysis and add Fe 0 Powder reduced Fe 3+ , and obtain Fe-rich 2+ solution, Fe 2+ It can catalyze H2O2 to produce more hydroxyl radicals with high oxidation potential, which are circulated for leaching of anode mud.

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