Method for gradient recovery of gold, selenium and tellurium from gold-selenium-tellurium concentrate
Through the steps of pressure leaching, reduction precipitation and chlorination leaching, the problem of low separation and recovery efficiency of gold, selenium and tellurium in copper anode mud was solved, efficient and environmentally friendly recovery of gold, selenium and tellurium was achieved, and high-purity recycled materials were provided for subsequent purification.
Patent Information
- Application Number
- CN202510713953.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-09-12
AI Technical Summary
In the traditional copper anode mud treatment process, the interference of impurity elements such as As, Sb, and Bi leads to low separation and recovery efficiency of rare and precious elements Au, Ag, Se, and Te. The existing semi-wet process has problems of flue gas pollution and high energy consumption.
The method of pressure leaching, reduction precipitation, chlorination leaching and cascade reduction is adopted to control the acidity, potential and temperature to recover gold, selenium and tellurium in stages. The redox reaction is carried out by alkali and reducing agent to achieve the cascade recovery of gold, selenium and tellurium.
It achieves efficient separation and resource recovery of gold, selenium and tellurium, reduces environmental pollution, lowers energy consumption and wastewater treatment costs, and provides high-purity recycled materials for subsequent purification.
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Figure CN120624834A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of hydrometallurgy and rare metal extraction, and in particular to a method for cascading recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials. Background Art
[0002] Traditional copper anode slime treatment processes, due to interference from impurity elements such as As, Sb, and Bi, mostly rely on a gradient recovery approach. This results in a lengthy process flow, and As, Sb, Bi, and other precious elements like Te and Pd are highly dispersed throughout the process, making efficient recovery impossible. Effectively separating impurity elements like As, Sb, and Bi from copper anode slime and efficiently enriching precious elements like Au, Ag, Se, and Te is key to the comprehensive recovery of valuable elements from copper anode slime. To improve the overall recovery rate of precious elements like Au, Ag, Se, and Te, the recovery process can only be shortened, allowing the precious elements to be recovered as alloys or concentrates at the front end, followed by cascade separation and recovery of valuable elements. Because selenium and tellurium have similar properties, the commonly used semi-wet process currently in production suffers from drawbacks such as flue gas pollution, high energy consumption, and lengthy processes. Therefore, a new, efficient and environmentally friendly method for the cascade extraction and staged recovery of gold, selenium, and tellurium from gold-selenium-tellurium concentrates is urgently needed. Summary of the Invention
[0003] In response to the problems raised in the background art, the present invention provides a method for cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials to solve the problems. The present invention will be further elaborated below.
[0004] A method for cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials is carried out according to the following steps:
[0005] S1) pressure leaching deselenium: taking some gold, selenium and tellurium enriched material, adding a certain amount of water and mixing evenly, adding alkali to the mixed solution in a certain proportion, passing an oxidizing gas, and performing an oxidation reaction. The reaction is carried out for a certain time, and then filtering and washing to obtain a leaching residue containing gold and tellurium and a pressure leaching solution;
[0006] S2) reducing and precipitating selenium by pressurized leaching solution: first adding a certain amount of acid to the selenium-containing pressurized leaching solution obtained in S1) to adjust the acidity, then adding a certain amount of reducing agent after reaching a certain acidity, and filtering and washing after the reaction reaches a certain potential to obtain crude selenium powder and a reduced solution;
[0007] S3) Chlorination leaching of the pressure leaching residue: adding a certain amount of sodium chlorate to the leaching residue obtained in S1) for chlorination leaching, reacting for a certain period of time, filtering and washing to obtain chlorination leaching residue and chlorination leachate containing other precious metals;
[0008] S4) Recovery of valuable metals by cascade reduction of the chlorinated leaching solution: A certain amount of reducing agent is added to the chlorinated leaching solution obtained in S3), and a certain potential is controlled to reduce the solution step by step to obtain coarse gold powder and coarse tellurium powder, as well as the reduced liquid. The coarse gold powder and the coarse tellurium powder enter the corresponding metal refining process respectively, and the reduced liquid is returned to the chlorinated leaching process as the chlorinated leaching replenisher.
[0009] Furthermore, the specific process of the pressure leaching reaction in S1) is: liquid-solid ratio 10-20:1, reaction temperature 150-300°C, reaction time 6-12h, stirring speed 300-600r / min, and reaction pressure 1.5-3.5MPa.
[0010] Furthermore, the specific process of the reduction reaction in S2) is as follows: initial reaction acidity is 50-100 g / L, reaction temperature is 40-80°C, reaction time is 20-40 h, stirring speed is 300-600 r / min, and reaction endpoint potential is -100-0 mv.
[0011] Furthermore, the specific process of the chlorination leaching in S3) is: liquid-solid ratio 5-10:1, reaction temperature 30-70°C, reaction time 3-6h, solution acidity 120-200g / L, chloride concentration 100-200g / L, and sodium chlorate dosage 80-150g / L.
[0012] Furthermore, the specific process of the stepwise reduction of valuable metals by the chlorinated leachate in S4) is as follows: the reaction temperature is 25-70°C, the end point reduction potential of the coarse gold powder is 500-600mv, and the end point reduction potential of the coarse tellurium powder is 240-320mv.
[0013] Furthermore, the alkali in S1) is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide, and the amount of the alkali is 100-200 g / L.
[0014] Furthermore, the oxidizing gas in S1) is one or both of compressed air and oxygen.
[0015] Furthermore, the acid in S2) is one or more of hydrochloric acid, sulfuric acid and oxalic acid, and the reducing agent is one or more of sodium sulfite, sodium bisulfite, liquid sulfur dioxide and industrial sulfur dioxide.
[0016] Furthermore, the reducing agent in S4) is one or more of sodium sulfite, sodium bisulfite and industrial sulfur dioxide.
[0017] Furthermore, the gold, selenium and tellurium concentrate in S1) is an intermediate material in the copper anode mud treatment process.
[0018] Beneficial effects: Compared with the existing technology:
[0019] 1. The method of the present invention for cascade recovery of gold, selenium and tellurium from gold-selenium-tellurium enriched materials can recover gold, selenium and tellurium from the gold-selenium-tellurium enriched materials in a cascade manner, provide qualified raw materials for subsequent purification processes, and achieve efficient separation and resource recovery of gold, selenium and tellurium;
[0020] 2. The method for cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials of the present invention uses pressurized alkaline leaching conditions for the separation of selenium from gold and tellurium, which is less corrosive to equipment, does not produce toxic and harmful gases, and has good on-site working conditions;
[0021] 3. The method of cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials of the present invention does not generate new chlorine-containing wastewater, thus reducing environmental pollution and lowering wastewater treatment costs;
[0022] 4. The reagents used in this method are cheap, the operation method is simple, and it is easy to industrialize, with important economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 : A process flow chart of a method for cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials of the present invention. DETAILED DESCRIPTION
[0024] Next, combine the Figure 1 A specific embodiment of the present invention is described in detail.
[0025] like Figure 1 As shown, the present invention provides a method for cascade recovery of gold, selenium and tellurium from gold, selenium and tellurium enriched materials, which is carried out according to the following steps:
[0026] S1) pressure leaching deselenium: taking some gold, selenium and tellurium enriched material, adding a certain amount of water and mixing evenly, adding alkali to the mixed solution in a certain proportion, passing an oxidizing gas, and performing an oxidation reaction. The reaction is carried out for a certain time, and then filtering and washing to obtain a leaching residue containing gold and tellurium and a pressure leaching solution;
[0027] S2) reducing and precipitating selenium by pressurized leaching solution: first adding a certain amount of acid to the selenium-containing pressurized leaching solution obtained in S1) to adjust the acidity, then adding a certain amount of reducing agent after reaching a certain acidity, and filtering and washing after the reaction reaches a certain potential to obtain crude selenium powder and a reduced solution;
[0028] S3) Chlorination leaching of the pressure leaching residue: adding a certain amount of sodium chlorate to the leaching residue obtained in S1) for chlorination leaching, reacting for a certain period of time, filtering and washing to obtain chlorination leaching residue and chlorination leachate containing other precious metals;
[0029] S4) Recovery of valuable metals by cascade reduction of the chlorinated leaching solution: A certain amount of reducing agent is added to the chlorinated leaching solution obtained in S3), and a certain potential is controlled to reduce the solution step by step to obtain coarse gold powder and coarse tellurium powder, as well as the reduced liquid. The coarse gold powder and the coarse tellurium powder enter the corresponding metal refining process respectively, and the reduced liquid is returned to the chlorinated leaching process as the chlorinated leaching replenisher.
[0030] The specific process of the pressure leaching reaction in S1) is: liquid-solid ratio 10-20:1, reaction temperature 150-300°C, reaction time 6-12h, stirring speed 300-600r / min, and reaction pressure 1.5-3.5MPa.
[0031] The specific process of the reduction reaction in S2) is as follows: initial reaction acidity is 50-100 g / L, reaction temperature is 40-80°C, reaction time is 20-40 h, stirring speed is 300-600 r / min, and reaction endpoint potential is -100-0 mv.
[0032] The specific process of the chlorination leaching in S3) is: liquid-solid ratio 5-10:1, reaction temperature 30-70°C, reaction time 3-6h, solution acidity 120-200g / L, chloride concentration 100-200g / L, and sodium chlorate dosage 80-150g / L.
[0033] The specific process of the stepwise reduction of valuable metals with the chlorinated leachate in S4) is as follows: the reaction temperature is 25-70°C, the end point reduction potential of the coarse gold powder is 500-600mv, and the end point reduction potential of the coarse tellurium powder is 240-320mv.
[0034] The alkali in S1) is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide, and the amount of the alkali is 100-200 g / L.
[0035] The oxidizing gas in S1) is one or both of compressed air and oxygen.
[0036] The acid in S2) is one or more of hydrochloric acid, sulfuric acid and oxalic acid, and the reducing agent is one or more of sodium sulfite, sodium bisulfite, liquid sulfur dioxide and industrial sulfur dioxide.
[0037] The reducing agent in S4) is one or more of sodium sulfite, sodium bisulfite and industrial sulfur dioxide. The gold, selenium and tellurium concentrate in S1) is an intermediate material in the copper anode mud treatment process.
[0038] Example 1
[0039] See attached Figure 1(1) The composition of the gold, selenium and tellurium concentrate from the copper anode mud intermediate material is shown in Table 1. Take some of the gold, selenium and tellurium concentrate, add water at a liquid-solid ratio of 10:1 and mix well. Add 100 g / L of sodium hydroxide to the mixed solution in a pressure autoclave, introduce oxygen, and carry out an oxidation reaction. The reaction temperature is 150°C, the reaction time is 12 h, the stirring speed is 300 r / min, and the reaction pressure is 1.5 MPa. After filtration and washing, a pressure leaching residue and a pressure leaching solution containing tellurium and gold are obtained. The composition of the pressure leaching solution is shown in Table 2.
[0040] Table 1 Composition of gold, selenium and tellurium enriched material (%)
[0041] Element type Se Te Au content 56.54 29.79 0.50
[0042] Table 2 Composition of pressure leachate (g / l)
[0043] Element type Se Te Au content 48.37 0.006 ＜0.005
[0044] As shown in Tables 1 and 2, the selenium leaching rate is 99.38%, which is greater than 99%. The leaching residue is used as the raw material for chlorination leaching and enters the chlorination leaching process, and the pressurized leaching liquid is used as the raw material for extracting elemental selenium and enters the reduction process.
[0045] (2) Hydrochloric acid was added to the pressurized leaching solution in a certain proportion to adjust the acidity. The initial acidity of the solution was 50 g / L, the reducing agent was sodium sulfite, the reaction temperature was 40 ° C, the reaction time was 40 h, the stirring speed was 600 r / min, and the reaction endpoint potential was -100 mv. After filtration and washing, crude selenium powder containing only selenium and a reduced liquid were obtained. The composition of the reduced liquid is shown in Table 3.
[0046] Table 3 Composition of the reduced solution (g / l)
[0047] Element type Se Te Au content 0.114 0.008 ＜0.005
[0048] As shown in Table 3, the precipitation rate of selenium is 99.13%, which is greater than 99%. The crude selenium powder obtained is mainly selenium element, which enters the selenium refining and purification process, and the reduced liquid enters the wastewater treatment process.
[0049] (3) Chloride leaching was performed on the pressure leaching residue. Take some pressure leaching residue, add water and hydrochloric acid at a liquid-to-solid ratio of 5:1, and mix well. Add 80g / L of sodium chlorate to the mixed solution. The initial acidity of the solution is 120g / L. The chloride ion is supplemented with sodium chloride to 100g / L. The reaction temperature is 70℃, the reaction time is 3h, and the stirring speed is 300r / min. After filtering and washing, the chloride leaching residue and chloride leaching solution containing other rare and precious metals are obtained. The composition of the chloride leaching solution is shown in Table 4.
[0050] Table 4 Composition of chlorinated leachate (g / l)
[0051]
[0052]
[0053] As shown in Table 4, the tellurium leaching rate is 98.21%, and the gold leaching rate is 99.72%, both exceeding 95%. The chloride leachate primarily contains gold and tellurium, which enter the gold and tellurium recovery process. The chloride leach residue is used as high-quality raw material for the extraction of other precious metals in the precious metal refining process.
[0054] (4) The chlorinated leachate was subjected to a stepwise reduction to recover valuable metals. Sodium sulfite solution was added to the chlorinated leachate at a reaction temperature of 70°C. When the oxidation potential of the reaction solution reached 600 mV, the reaction was suspended. After filtration and multiple hot water washings, crude gold powder and a gold precipitation solution were obtained. Sodium sulfite solution was further added to the gold precipitation solution at a reaction temperature of 70°C. When the oxidation potential of the reaction solution reached 320 mV, the reaction was terminated. After filtration and hot water washing, crude tellurium powder and a reduced solution were obtained. The composition of the reduced solution is shown in Table 5.
[0055] Table 5 Composition of reducing solution (g / l)
[0056] Element type Se Te Au content 0.007 0.013 ＜0.005
[0057] The selenium leaching rate of the entire process can reach more than 99%, the selenium recovery rate can reach more than 99%, the gold recovery rate of chloride leaching can reach more than 99%, and the tellurium recovery rate can reach more than 95%. The separation effect of selenium and tellurium is good, the leaching selectivity is good, and the recovery rate is high; the crude selenium powder, crude tellurium powder and crude gold powder have low impurity content, which is conducive to the next step of refining and purification, and increases the added value of the product.
[0058] Example 2
[0059] See attached Figure 1 (1) The composition of the gold, selenium and tellurium concentrate from the copper anode mud intermediate material is shown in Table 6. Take some of the gold, selenium and tellurium concentrate, add water at a liquid-solid ratio of 15:1 and mix well. Add 150 g / L of potassium hydroxide to the mixed solution in a pressure autoclave, and introduce compressed air to carry out an oxidation reaction. The reaction temperature is 250°C, the reaction time is 8 hours, the stirring speed is 450 r / min, and the reaction pressure is 2.5 MPa. After filtration and washing, a pressure leaching residue and a pressure leaching solution containing tellurium and gold are obtained. The composition of the pressure leaching solution is shown in Table 7.
[0060] Table 6 Composition of gold, selenium and tellurium enriched material (%)
[0061] Element type Se Te Au content 57.31 29.69 0.31
[0062] Table 7 Composition of pressure leachate (g / l)
[0063] Element type Se Te Au content 44.52 0.015 ＜0.005
[0064] As shown in Tables 6 and 7, the selenium leaching rate is 99.51%, which is greater than 99%. The leaching residue is used as the raw material for chlorination leaching and then enters the chlorination leaching process. The pressurized leaching liquid is used as the raw material for extracting elemental selenium and then enters the reduction process.
[0065] (2) Sulfuric acid was added to the pressurized leaching solution in a certain proportion to adjust the acidity. The initial acidity of the solution was 100 g / L. The reducing agent was sodium bisulfite. The reaction temperature was 60 ° C. The reaction time was 30 h. The stirring speed was 450 r / min. The reaction endpoint potential was -50 mv. After filtration and washing, crude selenium powder containing only selenium and a reduced liquid were obtained. The composition of the reduced liquid is shown in Table 8.
[0066] Table 8 Composition of the reduced solution (g / l)
[0067] Element type Se Te Au content 0.231 0.011 ＜0.005
[0068] As shown in Table 8, the precipitation rate of selenium is 99.63%, which is greater than 99%. The crude selenium powder obtained is mainly selenium element, which enters the selenium refining and purification process, and the reduced liquid enters the wastewater treatment process.
[0069] (3) Chloride leaching was performed on the pressure leaching residue. Take some pressure leaching residue, add water and hydrochloric acid at a liquid-to-solid ratio of 8:1, and mix well. Add 120g / L of sodium chlorate to the mixed solution. The initial acidity of the solution is 160g / L. The chloride ion is supplemented with sodium chloride to 150g / L. The reaction temperature is 50℃, the reaction time is 5h, and the stirring speed is 500r / min. After filtering and washing, the chloride leaching residue and chloride leaching solution containing other rare and precious metals are obtained. The composition of the chloride leaching solution is shown in Table 9.
[0070] Table 9 Composition of chlorinated leachate (g / l)
[0071] Element type Se Te Au content 0.012 19.33 2.52
[0072] Table 9 shows that the tellurium leaching rate is 98.92%, and the gold leaching rate is 99.82%, both exceeding 95%. The chloride leachate primarily contains gold and tellurium, which enter the gold and tellurium recovery process. The chloride leach residue is used as high-quality raw material for the extraction of other precious metals in the precious metal refining process.
[0073] (4) The chlorinated leachate was subjected to a stepwise reduction to recover valuable metals. Sodium bisulfite solution was added to the chlorinated leachate at a reaction temperature of 50°C. When the oxidation potential of the reaction solution reached 550 mV, the reaction was suspended. After filtration and multiple hot water washings, crude gold powder and a gold precipitation solution were obtained. Sodium sulfite solution was further added to the gold precipitation solution at a reaction temperature of 50°C. When the oxidation potential of the reaction solution reached 280 mV, the reaction was terminated. After filtration and hot water washing, crude tellurium powder and a reduced solution were obtained. The composition of the reduced solution is shown in Table 10.
[0074] Table 10 Composition of reducing solution (g / l)
[0075] Element type Se Te Au content 0.010 0.022 ＜0.005
[0076] The selenium leaching rate of the entire process can reach more than 99%, the selenium recovery rate can reach more than 99%, the gold recovery rate of chloride leaching can reach more than 99%, and the tellurium recovery rate can reach more than 95%. The separation effect of selenium and tellurium is good, the leaching selectivity is good, and the recovery rate is high; the crude selenium powder, crude tellurium powder and crude gold powder have low impurity content, which is conducive to the next step of refining and purification, and increases the added value of the product.
[0077] Example 3
[0078] See attached Figure 1 (1) The composition of the gold, selenium and tellurium concentrate from the copper anode mud intermediate material is shown in Table 11. Take some of the gold, selenium and tellurium concentrate, add water at a liquid-solid ratio of 20:1 and mix well. Add 200 g / L of calcium hydroxide to the mixed solution in a pressure autoclave, introduce compressed air, and carry out an oxidation reaction at a reaction temperature of 300°C, a reaction time of 6 h, a stirring speed of 600 r / min, and a reaction pressure of 3.5 MPa. After filtration and washing, a pressure leaching residue and a pressure leaching solution containing tellurium and gold are obtained. The composition of the pressure leaching solution is shown in Table 12.
[0079] Table 11 Composition of gold, selenium and tellurium enriched material (%)
[0080] Element type Se Te Au content 54.88 27.39 0.55
[0081] Table 12 Composition of pressure leachate (g / l)
[0082] Element type Se Te Au content 42.69 0.029 ＜0.005
[0083] As shown in Tables 11 and 12, the selenium leaching rate is 99.33%, which is greater than 99%. The leaching residue is used as the raw material for chlorination leaching and then enters the chlorination leaching process. The pressurized leaching liquid is used as the raw material for extracting elemental selenium and then enters the reduction process.
[0084] (2) Oxalic acid was added to the pressurized leaching solution in a certain proportion to adjust the acidity. The initial acidity of the solution was 80 g / L. The reducing agent was industrial sulfur dioxide. The reaction temperature was 80 ° C. The reaction time was 20 h. The stirring speed was 600 r / min. The reaction endpoint potential was 0 mv. After filtration and washing, crude selenium powder containing only selenium and a reduced liquid were obtained. The composition of the reduced liquid is shown in Table 13.
[0085] Table 13 Composition of the reduced solution (g / l)
[0086] Element type Se Te Au content 0.185 0.016 ＜0.005
[0087] As shown in Table 13, the precipitation rate of selenium is 99.44%, which is greater than 99%. The crude selenium powder obtained is mainly selenium element, which enters the selenium refining and purification process, and the reduced liquid enters the wastewater treatment process.
[0088] (3) Chloride leaching was performed on the pressure leaching residue. Take some pressure leaching residue, add water and sulfuric acid at a liquid-to-solid ratio of 10:1, and mix well. Add 150g / L of sodium chlorate to the mixed solution. The initial acidity of the solution is 200g / L. The chloride ion is supplemented with sodium chloride to 200g / L. The reaction temperature is 30℃, the reaction time is 6h, and the stirring speed is 600r / min. After filtering and washing, the chloride leaching residue and chloride leaching solution containing other rare and precious metals are obtained. The composition of the chloride leaching solution is shown in Table 14.
[0089] Table 14 Composition of chlorinated leachate (g / l)
[0090]
[0091]
[0092] Table 14 shows that the tellurium leaching rate is 98.74%, and the gold leaching rate is 99.88%, both exceeding 95%. The chloride leachate primarily contains gold and tellurium, which enter the gold and tellurium recovery process. The chloride leach residue is used as high-quality raw material for the extraction of other precious metals in the precious metal refining process.
[0093] (4) The chlorinated leachate is subjected to a stepwise reduction process to recover valuable metals. Industrial sulfur dioxide gas is introduced into the chlorinated leachate at a reaction temperature of 25°C. When the oxidation potential of the reaction solution reaches 500 mV, the reaction is suspended. After filtration and multiple hot water washings, crude gold powder and a gold precipitation solution are obtained. Sodium sulfite solution is further added to the gold precipitation solution at a reaction temperature of 25°C. When the oxidation potential of the reaction solution reaches 240 mV, the reaction is terminated. After filtration and hot water washing, crude tellurium powder and a reduced solution are obtained. The composition of the reduced solution is shown in Table 15.
[0094] Table 15 Composition of reducing solution (g / l)
[0095] Element type Se Te Au content 0.012 0.025 ＜0.005
[0096] The selenium leaching rate of the entire process can reach more than 99%, the selenium recovery rate can reach more than 99%, the gold recovery rate of chloride leaching can reach more than 99%, and the tellurium recovery rate can reach more than 95%. The separation effect of selenium and tellurium is good, the leaching selectivity is good, and the recovery rate is high; the crude selenium powder, crude tellurium powder and crude gold powder have low impurity content, which is conducive to the next step of refining and purification, and increases the added value of the product.
[0097] The above describes in detail a method for the cascade recovery of gold, selenium, and tellurium from a gold-selenium-tellurium concentrate. The above embodiments are intended only to facilitate understanding of the method and its core concept. Furthermore, those skilled in the art will appreciate variations in the specific implementation and scope of application based on the concept of this application. Therefore, this specification should not be construed as limiting this application.
[0098] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.
[0099] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.
[0100] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.
[0101] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.
Claims
1. A method for recovering gold, selenium and tellurium from gold, selenium and tellurium concentrates in stages, characterized in that Follow these steps: S1) pressure leaching deselenium: taking some gold, selenium and tellurium enriched material, adding a certain amount of water and mixing evenly, adding alkali to the mixed solution in a certain proportion, passing an oxidizing gas, and performing an oxidation reaction. The reaction is carried out for a certain time, and then filtering and washing to obtain a leaching residue containing gold and tellurium and a pressure leaching solution; S2) reducing and precipitating selenium by pressurized leaching solution: first adding a certain amount of acid to the selenium-containing pressurized leaching solution obtained in S1) to adjust the acidity, then adding a certain amount of reducing agent after reaching a certain acidity, and filtering and washing after the reaction reaches a certain potential to obtain crude selenium powder and a reduced solution; S3) Chlorination leaching of the pressure leaching residue: adding a certain amount of sodium chlorate to the leaching residue obtained in S1) for chlorination leaching, reacting for a certain period of time, filtering and washing to obtain chlorination leaching residue and chlorination leachate containing other precious metals; S4) Recovery of valuable metals by cascade reduction of the chlorinated leaching solution: A certain amount of reducing agent is added to the chlorinated leaching solution obtained in S3), and a certain potential is controlled to reduce the solution step by step to obtain coarse gold powder and coarse tellurium powder, as well as the reduced liquid. The coarse gold powder and the coarse tellurium powder enter the corresponding metal refining process respectively, and the reduced liquid is returned to the chlorinated leaching process as the chlorinated leaching replenisher.
2. The method according to claim 1, characterized in that The specific process of the pressure leaching reaction in S1) is: liquid-solid ratio 10-20:1, reaction temperature 150-300°C, reaction time 6-12h, stirring speed 300-600r / min, and reaction pressure 1.5-3.5MPa.
3. The method according to claim 1, characterized in that The specific process of the reduction reaction in S2) is as follows: initial reaction acidity is 50-100 g / L, reaction temperature is 40-80°C, reaction time is 20-40 h, stirring speed is 300-600 r / min, and reaction endpoint potential is -100-0 mv.
4. The method according to claim 1, wherein The specific process of the chlorination leaching in S3) is: liquid-solid ratio 5-10:1, reaction temperature 30-70°C, reaction time 3-6h, solution acidity 120-200g / L, chloride concentration 100-200g / L, and sodium chlorate dosage 80-150g / L.
5. The method according to claim 1, characterized in that The specific process of recovering valuable metals by cascade reduction of the chlorinated leachate in S4) is as follows: the reaction temperature is 25-70°C, the end point reduction potential of the coarse gold powder is 500-600mv, and the end point reduction potential of the coarse tellurium powder is 240-320mv.
6. The method according to claim 1, characterized in that The alkali in S1) is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide, and the amount of the alkali is 100-200 g / L.
7. The method according to claim 1, characterized in that The oxidizing gas in S1) is one or both of compressed air and oxygen.
8. The method according to claim 1, characterized in that The acid in S2) is one or more of hydrochloric acid, sulfuric acid and oxalic acid, and the reducing agent is one or more of sodium sulfite, sodium bisulfite, liquid sulfur dioxide and industrial sulfur dioxide.
9. The method according to claim 1, characterized in that The reducing agent in S4) is one or more of sodium sulfite, sodium bisulfite and industrial sulfur dioxide.
10. The method according to claim 1, characterized in that The gold, selenium and tellurium enriched product in S1) is an intermediate material in the copper anode mud treatment process.