Full-wet comprehensive utilization method for valuable elements in nickel anode slime

Abstract

The invention discloses a full-wet comprehensive utilization method for valuable elements in nickel anode slime. The nickel anode slime valuable element all-wet comprehensive utilization method comprises the following steps: sequentially adding carbon disulfide, water and nickel anode slime into a closed container, and extracting to obtain a sulfur-containing extracting solution and metal extracting slag; evaporating the sulfur-containing extraction liquid to obtain carbon disulfide, water vapor and sulfur; the metal extraction slag is subjected to a biological oxidation reaction, and biological oxidation leachate and biological oxidation slag are obtained; thiourea and ferric sulfate are added into the biological oxidizing slag for leaching, and gold and silver leaching liquid and leaching slag are obtained; and the leaching residues are leached through a chlorination method, and a leaching solution containing platinum and palladium is obtained. According to the nickel anode slime valuable element all-wet comprehensive utilization method, extraction of seven valuable elements in nickel anode slime is achieved, energy consumption in the nickel anode slime treatment process is reduced, and the comprehensive utilization rate of nickel electrolysis production resources is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of comprehensive utilization of valuable elements, and in particular to a method for comprehensive utilization of valuable elements in nickel anode mud by a fully wet method. Background Art

[0002] Nickel anode slime is a byproduct of nickel sulfide electrolytic refining. It contains up to 80% sulfur, along with nickel sulfide, copper, and rare precious metals. Currently, the primary method for separating sulfur from nickel anode slime is to heat it to 120°C, converting the solid sulfur into a molten state. At this point, the sulfur is most fluid. The slime is then filtered while hot, leaving the hot residue on the upper filter surface and the sulfur below it. The hot residue is then returned to the smelting furnace and recast into anode plates for further electrolysis, achieving copper-nickel separation and precious metal enrichment. This process presents several challenges. First, due to the high sulfur content in nickel anode slime, heating it produces sulfur dioxide gas, which pollutes the plant environment. Second, continuous heating is required during the screening process to prevent the sulfur from solidifying and clogging the screen mesh after cooling. Furthermore, the sulfur product obtained from hot filtration is of low purity. Finally, the hot residue is difficult to dispose of directly and must be recast into anode plates for further electrolysis. This increased process flow can easily lead to indirect metal loss, reducing the efficiency of nickel anode slime resource utilization and increasing energy consumption. Summary of the Invention

[0003] In order to solve the technical problem that the above-mentioned existing nickel anode mud treatment methods are very likely to cause indirect metal loss, reduce the efficiency of nickel anode mud resource utilization and increase energy consumption, the present invention provides a fully wet comprehensive utilization method of valuable elements in nickel anode mud, which realizes the extraction of seven valuable elements in nickel anode mud, effectively reduces the energy consumption in the nickel anode mud treatment process, improves the recovery rate of each component and the comprehensive utilization rate of nickel electrolysis production resources, and solves the problems of low recovery rate of each component of nickel anode mud and high energy consumption of the recovery process that are currently common in the recovery and treatment process of nickel anode mud residue. The process has good economic benefits.

[0004] The present invention provides a fully wet comprehensive utilization method of valuable elements in nickel anode mud, comprising the following steps:

[0005] Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, then add appropriate amounts of nickel anode mud, stir and extract for 1 to 2 hours at room temperature, and then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue;

[0006] Step 2: Evaporating the sulfur-containing extract to obtain carbon disulfide vapor, water vapor, and sulfur product;

[0007] Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue and place it in 9K culture medium for biological oxidation reaction. After the reaction is completed, perform solid-liquid separation under room temperature to obtain biological oxidation leaching solution and biological oxidation residue;

[0008] Step 4: adding an appropriate amount of thiourea solution and ferric sulfate to the biological oxidation slag, adjusting the pH, and then leaching at room temperature for 5 to 10 hours, and then performing solid-liquid separation to obtain gold and silver leachate and leach residue;

[0009] Step 5: Add appropriate amounts of sodium chlorate and sodium chloride to the leaching residue, adjust the solution potential and pH, and then leach for 6 to 12 hours, and then perform solid-liquid separation to obtain a leaching solution containing platinum and palladium.

[0010] In a preferred embodiment of the method for fully wet comprehensive utilization of valuable elements in nickel anode mud provided by the present invention, in step 1, the mass ratio of the carbon disulfide, the water and the nickel anode mud is (3-5):8:1.

[0011] In a preferred embodiment of the fully wet comprehensive utilization method of valuable elements in nickel anode mud provided by the present invention, in the step 2, the evaporation treatment is: adding the sulfur-containing extract to a distillation device and evaporating it in a water bath at 60-80° C. for 5-10 minutes.

[0012] In a preferred embodiment of the fully wet comprehensive utilization method of valuable elements in nickel anode mud provided by the present invention, in the step 2, the obtained carbon disulfide vapor and the water vapor are cooled by a condenser and then enter the step 1.

[0013] In a preferred embodiment of the method for fully wet comprehensive utilization of valuable elements in nickel anode mud provided by the present invention, in the step 3, the mixed bacterial solution is prepared by mixing the bacterial solution of Acidithiobacillus ferrooxidans and the bacterial solution of Acidithiobacillus thiooxidans in a volume ratio of (0.8-1.2):1, and the bacterial concentration of the mixed bacterial solution is 7×10 7 ~8×10 7 CFU / mL; the inoculation amount of the mixed bacterial solution is 10% to 30%; the pH value of the 9K culture medium is 1.8 to 2.0; the conditions of the biological oxidation reaction are 25 to 30° C. and a shaking speed of 150 to 200 rpm.

[0014] In a preferred embodiment of the fully wet comprehensive utilization method of valuable elements in nickel anode mud provided by the present invention, in the step four, the concentration of the thiourea solution is 0.2-1 mol / L, the amount of ferric sulfate is 0.2-0.4 mol / L, and the pH is adjusted to 1-2.

[0015] In a preferred embodiment of the fully wet comprehensive utilization method of valuable elements in nickel anode mud provided by the present invention, in the step five, the amount of sodium chlorate is 0.2-0.4wt%, the amount of sodium chloride is 8-16wt%, the solution potential is controlled to be 800-1000mV, the pH is adjusted to 0.5-1, and the leaching reaction temperature is 30-50°C.

[0016] This invention integrates carbon disulfide desulfurization, biological oxidation leaching of copper and nickel, thiourea leaching of gold and silver, and chloride leaching of platinum and palladium to create a highly adaptable and synergistic, full-process wet recovery process. Based on an analysis of metal occurrence states, this combined process prioritizes multi-metal synergistic extraction and efficient resource utilization, scientifically designing the sequence of steps and rationally matching leaching conditions to achieve efficient recovery of multiple components from nickel anode slime.

[0017] Specifically, a carbon disulfide mixed water system is first used to extract and separate elemental sulfur at room temperature, breaking the structural barriers that enclose the metal and creating a transparent environment for subsequent metal leaching. The mixed water process avoids the volatility of carbon disulfide, and distillation can effectively separate sulfur and recover the extractant, achieving circular production. Subsequently, acidophilic bacteria are used to bio-oxidize and leach copper and nickel, which not only recovers valuable metals but also further promotes the enrichment of precious metals in the residue and reduces the consumption of leaching agents in the back-end leaching process. After copper and nickel are recovered, thiourea and oxidants are used to dissolve gold and silver in an acidic environment. Finally, a high oxidation potential chlorination system is used in the leached residue after the interfering components have been removed to achieve selective dissolution of platinum and palladium, ensuring the efficient recovery of platinum group metals. As a secondary resource rich in precious metals and heavy metals, nickel anode mud is of great significance for the full separation and recovery of precious metal resources using a cascade recovery process.

[0018] This process embodies comprehensive optimization in the laws of metal phase transformation, differences in chemical behavior of each component and operational economy, significantly improving the resource utilization efficiency of all components of nickel anode mud.

[0019] Compared with the prior art, the all-wet comprehensive utilization method of valuable elements in nickel anode mud provided by the present invention has the following beneficial effects:

[0020] 1. By mixing carbon disulfide with water at room temperature, elemental sulfur in nickel anode mud can be extracted to separate solid sulfur, improve sulfur separation efficiency, reduce energy consumption in the production process, and avoid the overflow of sulfur dioxide gas affecting the production environment. The water mixing process solves the problem of carbon disulfide's volatility and increases the fluidity of the extractant.

[0021] 2. The distillation process realizes the recycling of the extractant, and a sulfur product with a purity of more than 99.5% can be prepared by a single extraction of carbon disulfide.

[0022] 3. Through the biological oxidation process, the separation and recovery of copper and nickel, the enrichment of precious metals and the deep removal of sulfur are achieved under room temperature conditions.

[0023] 4. Through the wet process, the cascade recovery of precious metals is achieved under low temperature conditions. Thiourea realizes the leaching of gold and silver, chlorination enhances the leaching of gold, and realizes the leaching of platinum group metals.

[0024] 5. The present invention realizes the extraction of seven valuable elements from nickel anode mud, effectively reduces the energy consumption in the nickel anode mud treatment process, improves the recovery rate of each component and the comprehensive utilization rate of nickel electrolysis production resources, and solves the common problems of low recovery rate of each component of nickel anode mud and high energy consumption in the recovery process in the current recovery and treatment of nickel anode mud residue. The process has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0026] Figure 1 This is a flow chart of the method for comprehensive utilization of valuable elements in nickel anode mud provided by the present invention;

[0027] Figure 2 1. It is a graph showing the nickel anode mud extraction rate and the extraction agent recovery rate at different extraction liquid-to-solid ratios in the present invention;

[0028] Figure 3 1. The nickel anode mud extraction rate and the extraction agent recovery rate at different CS2:NAS:H2O ratios in the present invention;

[0029] Figure 4 1 is a graph showing the carbon disulfide extraction recovery at different temperatures in the present invention;

[0030] Figure 5 This is a diagram of the extraction result of the extractant circulation in the present invention;

[0031] Figure 6 is a graph showing the leaching rates of Cu and Ni by Thiobacillus ferrooxidans and Thiobacillus thiooxidans in the present invention;

[0032] Figure 7 This is a graph showing the change in Au leaching rate under different thiourea and ferric sulfate concentration gradients in the present invention;

[0033] Figure 8 This is a graph showing the change in Ag leaching rate under different thiourea and ferric sulfate concentration gradients in the present invention;

[0034] Figure 9 It is a schematic diagram of the flow of cascade recovery elements in the present invention. DETAILED DESCRIPTION

[0035] 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] See also Figure 1 , Figure 1 The present invention provides a flow chart of a method for fully wet comprehensive utilization of valuable elements in nickel anode mud.

[0037] The method for comprehensive utilization of valuable elements in nickel anode mud by fully wet method comprises the following steps:

[0038] Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, then add appropriate amounts of nickel anode mud, stir and extract for 1 to 2 hours at room temperature, and then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue;

[0039] Specifically, the mass ratio of the carbon disulfide, the water and the nickel anode mud is (3-5):8:1;

[0040] The sulfur in nickel anode mud encapsulates heavy metals and precious metals, limiting their leaching. Using carbon disulfide as an extractant allows for the separation and recovery of sulfur at room temperature and breaks down the sulfur encapsulation of the metals. If the sulfur content in nickel anode mud is high, the amount of water added can be increased to improve the liquid phase fluidity of the mixed extractant and thus the extraction efficiency. Since carbon disulfide is volatile, if the temperature in the production plant area is high, the amount of water added can be increased to reduce the volatilization loss of carbon disulfide during the extraction process.

[0041] Step 2: Evaporating the sulfur-containing extract to obtain carbon disulfide vapor, water vapor, and sulfur product;

[0042] Specifically, the evaporation treatment is as follows: adding the sulfur-containing extract to a distillation device and evaporating it in a water bath at 60 to 80° C. for 5 to 10 minutes; the obtained carbon disulfide vapor and water vapor are cooled in a condenser and then enter the step 1 to achieve the recovery and utilization of the extractant;

[0043] If the proportion of water is increased during the extraction process, the water bath distillation temperature can be appropriately increased, but the temperature of the sulfur-containing extract should be ensured not to exceed 90°C;

[0044] Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue and place it in 9K culture medium for biological oxidation reaction. After the reaction is completed, perform solid-liquid separation under room temperature to obtain biological oxidation leaching solution and biological oxidation residue;

[0045] Specifically, the Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans used in the present invention are both provided by the Key Laboratory of Biometallurgy of the Ministry of Education, Central South University, Changsha, Hunan Province; the mixed bacterial solution is prepared by mixing the Acidithiobacillus ferrooxidans bacterial solution and the Acidithiobacillus thiooxidans bacterial solution in a volume ratio of (0.8-1.2):1, and the bacterial concentration of the mixed bacterial solution is 7×10 7 ~8×10 7 CFU / mL; when preparing the mixed bacterial solution, the acidophilic thiobacillus ferrooxidans and the acidophilic thiobacillus thiooxidans are first activated, and then inoculated into 9K medium and cultured to the logarithmic phase, to obtain the acidophilic thiobacillus ferrooxidans bacterial solution and the acidophilic thiobacillus thiooxidans bacterial solution, and the bacterial concentration of the acidophilic thiobacillus ferrooxidans bacterial solution and the acidophilic thiobacillus thiooxidans bacterial solution is not less than 10 8 CFU / mL; the inoculation amount of the mixed bacterial solution is 10% to 30%; the pH value of the 9K culture medium is 1.8 to 2.0; the conditions of the biological oxidation reaction are 25 to 30° C. and a shaking speed of 150 to 200 rpm.

[0046] If the sulfur content in the extracted metal slag is high, the proportion of Thiobacillus thiooxidans is appropriately increased; if the copper sulfide and nickel sulfide contents are high, the proportion of Thiobacillus ferrooxidans is appropriately increased to increase the biological oxidation rate;

[0047] Step 4: adding an appropriate amount of thiourea and ferric sulfate to the biological oxidation slag, adjusting the solid-liquid ratio and pH, and then leaching for 5 to 10 hours at room temperature, and then separating the solid and liquid to obtain a precious metal leachate and leach residue containing gold and silver;

[0048] Specifically, the concentration of the thiourea solution is 0.2-1 mol / L, the amount of ferric sulfate is 0.2-0.4 mol / L, and the pH is adjusted to 1-2;

[0049] Step 5: Add appropriate amounts of sodium chlorate and sodium chloride to the leaching residue, adjust the solution potential and pH, and then leach for 6 to 12 hours, and then perform solid-liquid separation to obtain a leaching solution containing platinum and palladium.

[0050] Specifically, the amount of sodium chlorate is 0.2-0.4 wt %, the amount of sodium chloride is 8-16 wt %, the solution potential is controlled to be 800-1000 mV, the pH is adjusted to be 0.5-1, and the leaching reaction temperature is 30-50° C.

[0051] Example 1

[0052] A new process for the comprehensive utilization of nickel anode mud by a fully wet method comprises the following steps:

[0053] Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, and then add appropriate amounts of nickel anode mud, so that the mass ratio of the carbon disulfide, the water, and the nickel anode mud is maintained at 3:8:1. Stir and extract at room temperature for 1 hour, then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue;

[0054] Step 2: adding the sulfur-containing extract to a distillation apparatus and evaporating it in a water bath at 60°C for 5 minutes. The generated carbon disulfide vapor and water vapor are cooled by a condenser and then enter the extraction process of step 1. The sulfur product is obtained at the bottom of the distillation apparatus;

[0055] Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue. The mixed bacterial solution is a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans at a volume ratio of 0.8:1. The inoculation amount of the mixed bacterial solution is 10%, and the bacterial concentration in the mixed bacterial solution is ensured to be 7×10 7 ~8×10 7 CFU / mL, the mixed system was placed in a 9K culture medium with a pH value of 1.8, and a biooxidation reaction was carried out at 25°C and a shaking speed of 150 rpm for 7 days; after the biooxidation was completed, solid-liquid separation was carried out at room temperature to obtain a biooxidation leaching solution containing copper and nickel and a biooxidation slag enriched in precious metals, and the biooxidation leaching solution can be used as an electrolyte after impurity removal treatment;

[0056] Step 4: Add thiourea solution and ferric sulfate to the biological oxidation slag, the thiourea concentration is 0.2 mol / L, the Fe2(SO4)3 dosage is 0.2 mol / L, the pH is adjusted to 1, and after leaching for 10 hours at room temperature, solid-liquid separation is performed to obtain gold and silver leachate and leach residue;

[0057] Step 5: adding sodium chlorate and sodium chloride to the leached residue, wherein the amount of sodium chlorate is 0.2wt% and the amount of sodium chloride is 8wt%, and leaching is carried out for 6h under the conditions of controlling the solution potential to 800mV, pH to 0.5, and reaction temperature to 30°C to obtain a leachate containing platinum and palladium.

[0058] Example 2

[0059] A new process for the comprehensive utilization of nickel anode mud by a fully wet method comprises the following steps:

[0060] Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, and then add appropriate amounts of nickel anode mud, so that the mass ratio of the carbon disulfide, the water, and the nickel anode mud is maintained at 4:8:1. Stir and extract at room temperature for 1.5 hours, then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue;

[0061] Step 2: adding the sulfur-containing extract to a distillation apparatus and evaporating it in a water bath at 70°C for 8 minutes. The generated carbon disulfide vapor and water vapor are cooled in a condenser and then enter the extraction process of step 1. The sulfur product is obtained at the bottom of the distillation apparatus;

[0062] Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue. The mixed bacterial solution is a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in a volume ratio of 1:1. The inoculation amount of the mixed bacterial solution is 20%, and the bacterial concentration in the mixed bacterial solution is ensured to be 7×10 7 ~8×10 7 CFU / mL, the mixed system was placed in a 9K culture medium with a pH value of 1.9, and a biooxidation reaction was carried out at 28°C and a shaking speed of 180 rpm for 8 days; after the biooxidation was completed, solid-liquid separation was carried out at room temperature to obtain a biooxidation leaching solution containing copper and nickel and a biooxidation slag enriched in precious metals, and the biooxidation leaching solution can be used as an electrolyte after impurity removal treatment;

[0063] Step 4: Add thiourea solution and ferric sulfate to the biological oxidation slag, the thiourea concentration is 0.6 mol / L, the Fe2(SO4)3 dosage is 0.3 mol / L, the pH is adjusted to 1.5, and leaching is carried out at room temperature for 7 hours, followed by solid-liquid separation to obtain gold and silver leachate and leach residue;

[0064] Step 5: adding sodium chlorate and sodium chloride to the leached residue, wherein the amount of sodium chlorate is 0.3wt% and the amount of sodium chloride is 12wt%, and leaching is carried out for 9h under the conditions of controlling the solution potential to 900mV, pH to 0.8, and reaction temperature to 40°C to obtain a leachate containing platinum and palladium.

[0065] Example 3

[0066] A new process for the comprehensive utilization of nickel anode mud by a fully wet method comprises the following steps:

[0067] Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, and then add appropriate amounts of nickel anode mud, so that the mass ratio of the carbon disulfide, the water, and the nickel anode mud is maintained at 5:8:1. Stir and extract at room temperature for 2 hours, then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue;

[0068] Step 2: adding the sulfur-containing extract to a distillation apparatus and evaporating it in a water bath at 80°C for 10 minutes. The generated carbon disulfide vapor and water vapor are cooled by a condenser and then enter the extraction process of step 1. The sulfur product is obtained at the bottom of the distillation apparatus;

[0069] Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue. The mixed bacterial solution is a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans at a volume ratio of 1.2:1. The inoculation amount of the mixed bacterial solution is 30%, and the bacterial concentration in the bacterial solution is ensured to be 7×10 7 ~8×10 7 CFU / mL, placing the mixed system in a 9K culture medium with a pH value of 2.0, and carrying out a biooxidation reaction at 30°C and a shaking speed of 200 rpm for 10 days; after the biooxidation is completed, solid-liquid separation is carried out at room temperature to obtain a biooxidation leaching solution containing copper and nickel and a biooxidation slag enriched in precious metals, and the biooxidation leaching solution can be used as an electrolyte after impurity removal treatment;

[0070] Step 4: Add thiourea solution and ferric sulfate to the biological oxidation slag, the thiourea concentration is 1 mol / L, the Fe2(SO4)3 dosage is 0.4 mol / L, the pH is adjusted to 2, and leaching is carried out at room temperature for 5 hours, followed by solid-liquid separation to obtain gold and silver leachate and leach residue;

[0071] Step 6: adding sodium chlorate and sodium chloride to the leached residue, wherein the amount of sodium chlorate is 0.4wt% and the amount of sodium chloride is 16wt%, and leaching is carried out for 12h under the conditions of controlling the solution potential to 1000mV, pH to 1, and reaction temperature to 50°C to obtain a leachate containing platinum and palladium.

[0072] Example 4: Implementation of Carbon Disulfide Mixed Water Extraction Process

[0073] 1. Take a certain amount of nickel anode mud, extract it at room temperature with different liquid-solid ratios for 30 minutes, separate the solid and liquid, dry the extracted metal slag, and test the nickel anode mud extraction rate; distill the carbon disulfide extract at 50℃ for 20 minutes, and calculate the carbon disulfide recovery rate. The results are as follows: Figure 2 shown.

[0074] according to Figure 2 As shown, as the liquid-to-solid ratio of the extractant increased from 2 / 1 to 4 / 1, the extraction rate increased from 45.96% to 77.22%. When the liquid-to-solid ratio increased to 8 / 1, the extraction rate remained unchanged at 77.24%, indicating that at a liquid-to-solid ratio of 4 / 1, the liquid-to-solid ratio no longer affected the sulfur extraction rate. After solid-liquid separation, the carbon disulfide in the extract was recovered by distillation. Only the extractant with a liquid-to-solid ratio of 2 / 1 had an extraction rate exceeding 60%.

[0075] 2. Take a certain amount of nickel anode mud and extract it for 30 minutes at different ratios of carbon disulfide (CS2): nickel anode mud (NAS): water (H2O). Then separate the solid and liquid, dry the extracted desulfurized metal slag, and test the nickel anode mud extraction rate. Distill the carbon disulfide extract at 50℃ for 20 minutes and calculate the carbon disulfide recovery rate. The results are as follows: Figure 3 shown.

[0076] according to Figure 3 As shown, at a CS2:NAS:H2O ratio of 1:1:11, the extraction rate was 54% compared to a liquid-to-solid ratio of 1:1. The addition of water increased the carbon disulfide recovery from 57% to 84.75%. Increasing the CS2:NAS ratio from 2:1 to 4:1 increased the extraction rate from 65.28% to 78.80%. The carbon disulfide-water method significantly improved carbon disulfide recoveries, from 62% and 59% to 86.96% and 92.74%. The extraction efficiency was optimal at a CS2:NAS:H2O ratio of 4:1:8, resulting in the highest carbon disulfide recovery.

[0077] 3. Figure 4 The carbon disulfide recovery rate at different temperatures is shown in Figure 2. When the temperature exceeds 80°C, the carbon disulfide recovery effect is better. After the extraction time exceeds 10 minutes, the carbon disulfide recovery rate stabilizes and reaches 99.16%.

[0078] 4. The carbon disulfide recovered by distillation was used to extract nickel anode mud in a certain ratio of CS2:NAS:H2O. After 60 minutes of extraction, solid-liquid separation was performed and distillation was continued at 80℃ for 10 minutes to continue recovery. The above experiment was repeated 4 times. The results of the extraction agent circulation extraction are as follows: Figure 5 shown.

[0079] The above implementation cases show that the carbon disulfide mixed with water method enhances the fluidity of the extractant and strengthens the extraction effect. It utilizes the large specific heat capacity of water to reduce the loss of the extractant during the extraction process. The extraction performance of the carbon disulfide recovered by distillation is stable, and the recycling of the extractant is realized.

[0080] Example 5: Implementation of the Carbon Disulfide Extraction Residue Biooxidation Process

[0081] A certain amount of nickel anode mud was placed in a conical flask, and 15% of Acidithiobacillus errooxidans (Af) and Acidithiobacillus thiooxidans (At) were inoculated respectively. Then, sufficient 9K culture medium was added, and the pH of the solution was adjusted to 1.8. The two bacteria were acclimated in a shaker at a temperature of 30°C and a speed of 180 rpm, and the changes in the leaching rate of copper and nickel were detected. The results are as follows. Figure 6 shown.

[0082] according to Figure 6 As shown in the figure, after 15 days of biological oxidation, the leaching rates of Cu and Ni by Af bacteria were 83.74% and 76.53%, respectively, while the leaching rates of Cu and Ni by At bacteria were 81.62% and 72.61%, respectively.

[0083] Example 6: Implementation of Cascade Recovery of Precious Metals

[0084] Different thiourea concentration gradients and ferric sulfate concentration gradients were set at a rotation speed of 500 rpm to explore the changes in the leaching rates of the two precious metals Au and Ag.

[0085] according to Figure 7 As shown in the figure, when the thiourea dosage reaches or exceeds 0.5 mol / L, increasing the thiourea dosage can increase the leaching rate, but the leaching rates of Au and Ag reach a stable state. When the thiourea dosage is further increased to or exceeds 1.0 mol / L, increasing the thiourea dosage has no effect on the leaching rate.

[0086] according to Figure 8 As shown in the figure, when the amount of ferric sulfate reaches or exceeds 0.3 mol / L, increasing the amount of ferric sulfate can increase the leaching rate, but the leaching rates of Au and Ag reach a stable state. When the amount of ferric sulfate is further increased to or above 0.5 mol / L, the excessive ferric sulfate oxidizes thiourea, resulting in a decrease in the leaching rates of Au and Ag.

[0087] The leaching residue after thiourea leaching was then subjected to the chloride method to extract platinum and palladium, synergistically enhancing the precious metals that had not been leached in the first two stages. The results are shown in the table below.

[0088]

[0089]

[0090] The research results of leaching residue by chloride method show that the effective leaching of platinum and palladium can be achieved when the amount of sodium chlorate is 0.2-0.4wt%, the amount of sodium chloride is 8-16wt%, the reaction temperature is 30-50℃ and the leaching time is 6-12h.

[0091] The overall flow diagram of the cascade recycling elements is as follows: Figure 9 shown.

[0092] This invention integrates carbon disulfide desulfurization, biological oxidation leaching of copper and nickel, thiourea leaching of gold and silver, and chloride leaching of platinum and palladium to create a highly adaptable and synergistic, full-process wet recovery process. Based on an analysis of metal occurrence states, this combined process prioritizes multi-metal synergistic extraction and efficient resource utilization. Through a scientifically designed sequence of steps and optimally matched leaching conditions, this process achieves efficient recovery of multiple components from nickel anode mud.

[0093] Specifically, a carbon disulfide mixed water system is first used to extract and separate elemental sulfur at room temperature, breaking the structural barriers that enclose the metal and creating a transparent environment for subsequent metal leaching. The mixed water process avoids the volatility of carbon disulfide, and distillation can effectively separate sulfur and recover the extractant, achieving circular production. Subsequently, acidophilic bacteria are used to bio-oxidize and leach copper and nickel, which not only recovers valuable metals but also further promotes the enrichment of precious metals in the residue and reduces the consumption of leaching agents in the back-end leaching process. After copper and nickel are recovered, thiourea and oxidants are used in an acidic environment to enhance the dissolution of gold and silver. Finally, a high oxidation potential chlorination system is used in the leaching residue after the interfering components have been removed to achieve selective dissolution of platinum, ensuring the ultimate efficient recovery of platinum group metals. As a secondary resource rich in precious and heavy metals, nickel anode mud is of great significance for the full separation and recovery of precious metal resources using a cascade recovery process.

[0094] This process embodies comprehensive optimization in the laws of metal phase transformation, differences in chemical behavior of each component and operational economy, significantly improving the resource utilization efficiency of all components of nickel anode mud.

[0095] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for comprehensive utilization of valuable elements in nickel anode mud by a fully wet method, characterized in that: The following steps are involved: Step 1: Add appropriate amounts of carbon disulfide and water into a sealed container, then add appropriate amounts of nickel anode mud, stir and extract for 1 to 2 hours at room temperature, and then perform solid-liquid separation to obtain a sulfur-containing extract and metal extraction residue; Step 2: Evaporating the sulfur-containing extract to obtain carbon disulfide vapor, water vapor, and sulfur product; Step 3: Add an appropriate amount of mixed bacterial solution to the metal extraction residue and place it in 9K culture medium for biological oxidation reaction. After the reaction is completed, perform solid-liquid separation under room temperature to obtain biological oxidation leaching solution and biological oxidation residue; Step 4: adding an appropriate amount of thiourea solution and ferric sulfate to the biological oxidation slag, adjusting the pH, and then leaching at room temperature for 5 to 10 hours, and then performing solid-liquid separation to obtain gold and silver leachate and leach residue; Step 5: Add appropriate amounts of sodium chlorate and sodium chloride to the leaching residue, adjust the solution potential and pH, and then leach for 6 to 12 hours, and then perform solid-liquid separation to obtain a leaching solution containing platinum and palladium.

2. The method for comprehensive utilization of valuable elements in nickel anode mud according to claim 1, characterized in that: In the step 1, the mass ratio of the carbon disulfide, the water and the nickel anode mud is (3-5):8:

1.

3. The method for comprehensive utilization of valuable elements in nickel anode mud by all-wet method according to claim 1, characterized in that: In the step 2, the evaporation treatment is as follows: adding the sulfur-containing extract to a distillation device and evaporating it in a water bath at 60-80° C. for 5-10 minutes.

4. The method for comprehensive utilization of valuable elements in nickel anode mud by all-wet method according to claim 1, characterized in that: In the step 2, the obtained carbon disulfide vapor and water vapor are cooled by a condenser and then enter the step 1.

5. The method for comprehensive utilization of valuable elements in nickel anode mud by all-wet method according to claim 1, characterized in that: In the step 3, the mixed bacterial solution is prepared by mixing the bacterial solution of Acidithiobacillus ferrooxidans and the bacterial solution of Acidithiobacillus thiooxidans in a volume ratio of (0.8-1.2):1, and the bacterial concentration of the mixed bacterial solution is 7×10 7 ~8×10 7 CFU / mL; the inoculation amount of the mixed bacterial solution is 10% to 30%; the pH value of the 9K culture medium is 1.8 to 2.0; the conditions of the biological oxidation reaction are 25 to 30° C. and a shaking speed of 150 to 200 rpm.

6. The method for comprehensive utilization of valuable elements in nickel anode mud by all-wet method according to claim 1, characterized in that: In the step 4, the concentration of the thiourea solution is 0.2-1 mol / L, the amount of the ferric sulfate is 0.2-0.4 mol / L, and the pH is adjusted to 1-2.

7. The method for comprehensive utilization of valuable elements in nickel anode mud by all-wet method according to claim 1, characterized in that: In the step 5, the amount of sodium chlorate used is 0.2-0.4 wt %, the amount of sodium chloride used is 8-16 wt %, the solution potential is controlled to be 800-1000 mV, the pH is adjusted to be 0.5-1, and the leaching reaction temperature is 30-50° C.

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