Method for gradient separation and recovery of valuable metals from scrap copper anode slime

Abstract

The invention provides a method for gradient separation and recovery of valuable metals from scrap copper anode slime, and belongs to the technical field of scrap copper anode slime treatment methods.The method comprises the following steps that the scrap copper anode slime and an arsenic fixing agent are evenly mixed, and agglomeration and briquetting are conducted to form block masses; the arsenic fixing agent comprises metal oxide and / or metal peroxide; carrying out oxidizing roasting on the block mass; acid liquor is adopted for leaching, and copper, nickel and arsenic enter first leaching liquor; mixing the first slag phase with sodium salt, and roasting; and the roasted product is leached through alkali liquor, tin enters second leaching liquor, and a second slag phase is gold and silver enriched slag. According to the technical scheme, on the basis of the special occurrence states of various valuable metals in the scrap copper anode slime, the atmosphere and the temperature field are combined to regulate and control phase conversion, so that activation and reconstruction of specific metal components are achieved, then different leaching systems are used for step-by-step separation and recovery, and multi-section selective separation and recovery of the valuable metals in the scrap copper anode slime can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of methods for treating scrap copper anode mud, and in particular to a method for stepwise separation and recovery of valuable metals from scrap copper anode mud. Background Art

[0002] More than 80% of the world's copper is produced by the pyrometallurgical-electrolytic refining process. During the electrolytic refining process, 5-20 kg of copper anode mud is produced for every ton of anode mud copper consumed. Copper anode mud is rich in various valuable metal elements such as copper, nickel, lead, arsenic, tin, bismuth, gold and silver. It is an important raw material for extracting rare and precious metals and has a very high comprehensive recovery value. China is the world's largest copper producer and consumer, and the external dependence of the copper industry exceeds 70% all year round. Against the backdrop of the gradual depletion of high-quality primary copper resources and the impact of domestic and foreign environmental factors on the import and export of copper resources, a large amount of copper-containing waste (such as copper cables, electronic waste) and high-arsenic copper ore are used as raw materials for copper smelting, resulting in large fluctuations in the composition of mixed copper anode mud.

[0003] Unlike the original copper anode mud, which contains a large amount of scattered metals (selenium and tellurium) and has a relatively stable phase composition, the content of heavy metals tin, lead and arsenic in scrap copper anode mud is relatively high, and the amount of scattered metals and the phase composition fluctuate greatly due to the source of scrap copper. There are many reports on the existing copper anode mud pretreatment methods. Sulfate roasting-water leaching, pressurized oxidative acid leaching, etc. have good effects on the recovery of scattered metals. However, when treating high-arsenic scrap copper anode mud, the poisonous element arsenic and the valuable element tin tend to disperse. High-arsenic scrap copper anode mud contains arsenic and tin elements of different valence states. Arsenic and tin exist in various forms such as oxides, sulfides, and oxygen-containing acids. Their volatilization and solubility characteristics are different. Arsenic will form compounds with metals that are difficult to separate, thereby reducing the metal recovery rate, which is not conducive to the subsequent extraction of precious metals and efficient recovery of resources. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a method for stepwise separation and recovery of valuable metals from mixed copper anode mud, aiming to solve the technical problem that when treating high-arsenic mixed copper anode mud, the poisonous element arsenic and the valuable element tin tend to disperse, which is not conducive to the subsequent extraction of precious metals and efficient recovery of resources.

[0005] In a first aspect, the present invention provides a method for stepwise separation and recovery of valuable metals from copper anode mud, comprising the following steps: S1. Mixing the copper anode mud and the arsenic-fixing agent uniformly, forming agglomerates by pressing the agglomerates; the arsenic-fixing agent comprises metal oxides and / or metal peroxides; S2, oxidative roasting: oxidative roasting the agglomerate to obtain first roasted sand; S3, leaching the first roasted sand with an acid solution to obtain a first leachate and a first slag phase, and recovering copper, nickel, and arsenic in the first leachate respectively; S4, mixing the first slag phase with the sodium salt and then roasting to obtain a second roasted sand; S5. Leaching the second roasted sand with an alkali solution to obtain a second leachate and a second slag phase, recovering tin in the second leachate by evaporation and crystallization, wherein the second slag phase is a gold-silver enriched slag.

[0006] In the technical solution of the embodiment of the present application, the existence form of the main valuable metals in the mixed copper anode mud of the present application is different from that of natural ores. Arsenic mainly exists in the form of oxides, sulfides and arsenates, and copper, nickel and tin mostly exist in the form of sulfates, oxides and a small amount of sulfides. The components of various substances are complex.

[0007] The present application first performs oxidation roasting to activate and reconstruct the components. The presence of arsenic is not conducive to the subsequent recovery of metals, and low-valent arsenic is volatile. The purpose of oxidation roasting is mainly to oxidize arsenic oxides and sulfides into non-volatile arsenates; to convert tin sulfates and sulfides into stable cassiterite oxides; and to convert the sulfides or oxides of other valuable metals into soluble sulfates or arsenates. After activation and reconstruction, acid leaching is used to selectively separate and recover valuable metals. Under this leaching system, simultaneous and efficient leaching of copper, nickel and arsenic can be achieved, and at the same time, tin dioxide and precious metal chlorides (such as silver chloride) can be stably controlled to enter the first slag phase during the leaching process. After copper, arsenic and nickel are removed simultaneously, sodium salt roasting and alkaline leaching are carried out, and the tin oxide in the cassiterite phase is converted into sodium stannate by controlling the atmosphere and temperature; after sodium salt roasting, high-valent tin oxide and precious metal oxide are mainly present in the second roasted sand, and tin can be separated from precious metals by alkaline leaching, and sodium stannate is dissolved in the alkaline solution to allow tin to enter the second leaching solution. The second slag phase after leaching is mainly gold and silver enriched slag, which can be directly used as a raw material for gold and silver pyrometallurgy.

[0008] Preferably, the molar ratio of the sum of the metal elements in the arsenic-fixing agent to the arsenic contained in the mixed copper anode mud is 1.5-3.5.

[0009] Preferably, the arsenic-fixing agent includes one or more of copper oxide, nickel oxide, lead oxide, copper peroxide, nickel peroxide, and lead peroxide.

[0010] Preferably, the conditions for oxidative calcination in step S2 are: temperature of 400-800° C., and calcination time of 30 min-180 min.

[0011] Preferably, when the arsenic solid agent is a metal oxide, an oxygenating agent is added during the oxidation roasting process, and the oxygenating agent includes oxygen, and the volume percentage concentration of oxygen in the oxidation roasting atmosphere is controlled to be 25% to 80%.

[0012] In the technical solution of the embodiment of the present application, metal oxides or metal peroxides are used as arsenic-fixing agents. The arsenic-fixing agent may also be a mineral or waste material containing metal oxides or metal peroxides. After the arsenic-fixing agent is mixed with the copper-mixed anode mud, oxidative roasting is carried out under oxygen-enhancing conditions to achieve efficient activation and reconstruction of arsenic and tin components. Arsenic sulfides, arsenic oxides, etc. are promoted to be oxidized with the arsenic-fixing agent through oxidation-rich temperature roasting to generate non-volatile copper arsenate, nickel arsenate, lead arsenate, etc.

[0013] Oxidative roasting in the presence of an oxidizing agent can convert tin sulfate, tin sulfide, etc. into stable cassiterite phase oxides.

[0014] Preferably, in step S3, the solid-liquid ratio of the first roasted sand to the acid solution is 1 g: (4-10) mL; the acid solution includes 80-250 g / L H2SO4, 5-25 g / L Cl - ; The acid leaching temperature is 45~90℃, and the leaching time is 1~4h.

[0015] In the technical solution of the embodiment of the present application, under acid leaching conditions, the simultaneous leaching of some valuable metals copper, nickel and arsenate can be achieved, and at the same time, tin dioxide and silver chloride are controlled to be stably present in the first slag phase to achieve arsenic-tin separation.

[0016] Preferably, the conditions for calcining the sodium salt are: a temperature of 850-1050° C., an oxygen volume percentage concentration of 0.5%-21% in the calcining atmosphere, an amount of sodium salt added of 1.2-2.5 times the molar ratio of the tin content, and a calcining time of 30 min-120 min.

[0017] In the technical solution of the embodiment of the present application, during the sodium salt roasting process, the tin phase transformation can be achieved, and the tin oxide can be converted into sodium stannate.

[0018] Preferably, the sodium salt comprises one or more of sodium carbonate, sodium hydroxide and sodium bicarbonate.

[0019] Preferably, in step S5, the alkali solution is a 40-240 g / L NaOH solution, and the alkali solution leaching conditions are: the solid-liquid ratio of the second roasted sand to the alkali solution is 1 g: (8-20) mL, the temperature is 55-90° C., and the leaching time is 2-6 h.

[0020] In the technical solution of the embodiment of the present application, during the alkaline leaching process, sodium stannate can be leached out, while precious metals such as gold and silver are controlled to be stably present in the second slag phase.

[0021] Preferably, the gold-silver enriched slag enters the gold-silver pyrometallurgical smelting process as an alchemical raw material.

[0022] Different from the existing technical solutions, the beneficial effects of this application include: 1. The technical solution of the present application is based on the special occurrence state of various valuable metals in the mixed copper anode mud, and combines the atmosphere and temperature field to regulate the phase transformation to achieve the activation and reconstruction of specific metal components, and then uses different leaching systems for step-by-step separation and recovery, which can achieve multi-stage selective separation and recovery of valuable metals in the mixed copper anode mud.

[0023] 2. The priority and principle process of separation and extraction of valuable metals proposed in this application have strong selectivity and high recovery rate of valuable metals through coordinated regulation of roasting-leaching; the high enrichment ratio of precious metals greatly simplifies the subsequent purification process of precious metals.

[0024] 3. The technical solution of this application is simple to operate, low in cost, and has little environmental pollution. The entire process is conducive to energy conservation, emission reduction and green production.

[0025] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a process flow chart for the stepwise separation and recovery of valuable metals from mixed copper anode mud for this application. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0030] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] Unlike the original copper anode mud, which contains a large amount of scattered metals (selenium and tellurium) and has a relatively stable phase composition, the content of heavy metals tin, lead and arsenic in scrap copper anode mud is relatively high, and the amount of scattered metals and the phase composition fluctuate greatly due to the source of scrap copper. There are many reports on the existing copper anode mud pretreatment methods. Sulfate roasting-water leaching, pressurized oxidative acid leaching, etc. have good effects on the recovery of scattered metals. However, when treating high-arsenic scrap copper anode mud, the poisonous element arsenic and the valuable element tin tend to disperse. High-arsenic scrap copper anode mud contains arsenic and tin elements of different valence states. Arsenic and tin exist in various forms such as oxides, sulfides, and oxygen-containing acids. Their volatilization and solubility characteristics are different. Arsenic will form compounds with metals that are difficult to separate, thereby reducing the metal recovery rate, which is not conducive to the subsequent extraction of precious metals and efficient recovery of resources.

[0035] In order to solve the technical problem that when treating high-arsenic mixed copper anode mud, the poisonous element arsenic and the valuable element tin are dispersed, which is not conducive to the subsequent extraction of precious metals and efficient recovery of resources, the present application provides a method for step-by-step separation and recovery of valuable metals from mixed copper anode mud. The technical scheme of the present application is based on the special occurrence state of various valuable metals in mixed copper anode mud, combined with the atmosphere and temperature field to regulate the phase transformation to achieve the activation and reconstruction of specific metal components, and then use different leaching systems for step-by-step separation and recovery, so as to achieve multi-stage selective separation and recovery of valuable metals in mixed copper anode mud.

[0036] like Figure 1 As shown, in the first aspect, the embodiment of the present application provides a method for stepwise separation and recovery of valuable metals from miscellaneous copper anode mud, comprising the following steps: S1. Mixing the copper anode mud and the arsenic-fixing agent uniformly, forming agglomerates by pressing the agglomerates; the arsenic-fixing agent comprises metal oxides and / or metal peroxides; S2, oxidatively roasting the agglomerate to obtain first roasted sand; S3, leaching the first roasted sand with an acid solution to obtain a first leachate and a first slag phase, and connecting the first leachate containing copper, nickel and arsenic to an existing copper electrolyte treatment process to recover valuable metals; S4, mixing the first slag phase with the sodium salt and then roasting to obtain a second roasted sand; S5. Leaching the second roasted sand with an alkali solution to obtain a second leachate and a second slag phase, recovering tin in the second leachate by evaporation and crystallization, wherein the second slag phase is a gold and silver enriched slag; recovering tin from the tin-containing second leachate by evaporation and crystallization, or adding other salts to prepare chemical products.

[0037] In the technical solution of the embodiment of the present application, the existence form of the main valuable metals in the mixed copper anode mud of the present application is different from that of natural ores. Arsenic mainly exists in the form of oxides, sulfides and arsenates, and copper, nickel and tin mostly exist in the form of sulfates, oxides and a small amount of sulfides; the components of various substances are complex.

[0038] The present application first performs oxidative roasting to activate and reconstruct the components. The presence of arsenic is not conducive to the subsequent recovery of metals. The purpose of oxidative roasting is mainly to oxidize arsenic oxides and sulfides into non-volatile arsenates; tin sulfates and sulfides are converted into stable cassiterite oxides; and the sulfides or oxides of other valuable metals are converted into soluble sulfates or arsenates. After activation and reconstruction, acid leaching is used to selectively separate and recover valuable metals. Under this leaching system, simultaneous and efficient leaching of copper, nickel and arsenic can be achieved, and at the same time, tin dioxide and precious metal chlorides (such as silver chloride) are controlled to stably enter the first slag phase during the leaching process. After copper, arsenic and nickel are removed simultaneously, sodium salt roasting and alkaline leaching are carried out, and the tin oxide in the cassiterite phase is converted into sodium stannate by controlling the atmosphere and temperature; after sodium salt roasting, high-valent tin oxide and precious metal oxide are mainly present in the second roasted sand, and tin can be separated from precious metals by alkaline leaching, and sodium stannate is dissolved in the alkaline solution to allow tin to enter the second leaching solution. The second slag phase after leaching is mainly gold and silver enriched slag, which can be directly used as a raw material for gold and silver pyrometallurgy.

[0039] Preferably, the molar ratio of the sum of the metal elements in the arsenic-fixing agent to the arsenic contained in the mixed copper anode mud is 1.5-3.5.

[0040] Preferably, the arsenic-fixing agent includes one or more of copper oxide, nickel oxide, lead oxide, copper peroxide, copper peroxide, nickel peroxide, and lead peroxide.

[0041] Preferably, the conditions for oxidative calcination in step S2 are: temperature of 400-800° C., and calcination time of 30 min-180 min.

[0042] Preferably, when the arsenic solid agent is a metal oxide, an oxygenating agent is added during the oxidation roasting process, and the oxygenating agent includes oxygen, and the volume percentage concentration of oxygen in the oxidation roasting atmosphere is controlled to be 25% to 80%.

[0043] In the technical solution of the embodiment of the present application, metal oxides or metal peroxides are used as arsenic-fixing agents. The arsenic-fixing agent may also be a mineral or waste material containing metal oxides or metal peroxides. After the arsenic-fixing agent is mixed with the copper-mixed anode mud, oxidative roasting is carried out under oxygen-enhancing conditions to achieve efficient activation and reconstruction of arsenic and tin components. Arsenic sulfides, arsenic oxides, etc. are promoted to be oxidized with the arsenic-fixing agent through oxidation-rich temperature roasting to generate non-volatile copper arsenate, nickel arsenate, lead arsenate, etc.

[0044] Oxidative roasting in the presence of an oxidizing agent can convert tin sulfate, tin sulfide, etc. into stable cassiterite phase oxides.

[0045] Preferably, in step S3, the solid-liquid ratio of the first roasted sand to the acid solution is 1 g: (4-10) mL; the acid solution includes 80-250 g / L H2SO4, 5-25 g / L Cl -; The acid leaching temperature is 45~90℃, and the leaching time is 1~4h.

[0046] In the technical solution of the embodiment of the present application, under acid leaching conditions, the simultaneous leaching of some valuable metals copper, nickel and arsenate can be achieved, and at the same time, tin dioxide and silver chloride are controlled to be stably present in the first slag phase to achieve arsenic-tin separation.

[0047] Preferably, the conditions for calcining the sodium salt are: a temperature of 850-1050° C., an oxygen volume percentage concentration of 0.5%-21% in the calcining atmosphere, an amount of sodium salt added of 1.2-2.5 times the molar ratio of the tin content, and a calcining time of 30 min-120 min.

[0048] In the technical solution of the embodiment of the present application, during the sodium salt roasting process, the tin phase transformation can be achieved, and the tin oxide can be converted into sodium stannate.

[0049] Preferably, the sodium salt comprises one or more of sodium carbonate, sodium hydroxide and sodium bicarbonate.

[0050] Preferably, in step S5, the alkali solution is a 40-240 g / L NaOH solution, and the alkali solution leaching conditions are: the solid-liquid ratio of the second roasted sand to the alkali solution is 1 g: (8-20) mL, the temperature is 55-90° C., and the leaching time is 2-6 h.

[0051] In the technical solution of the embodiment of the present application, during the alkaline leaching process, sodium stannate can be leached out, while precious metals such as gold and silver are controlled to be stably present in the second slag phase.

[0052] Preferably, the gold-silver enriched slag enters the gold-silver pyrometallurgical smelting process as an alchemical raw material.

[0053] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0054] 1. Preparation method Example 1 Taking a certain mixed copper anode mud (metal content is Cu13.7%, As7.5%, Ni1.6%, Sn21.8%, Ag1.3%, Au0.3%) as raw material, an appropriate amount of arsenic solid agent is added and mixed and pressed into a mass, the added arsenic solid agent is copper peroxide, the molar ratio of copper in copper peroxide to arsenic in the mixed copper anode mud is 2, and oxidative roasting is performed to obtain the first roasted sand.

[0055] The oxidation roasting temperature is 650°C, the roasting time is 90 minutes, and the first roasted sand is obtained. The flue gas (arsenic content 1.3%) is recovered from the dust removal system; The first roasted sand is leached with acid solution, the acid solution leaching temperature is 70°C, the acid solution is composed of 80g / L sulfuric acid and 7g / L NaCl, the leaching time is 120min, and the first leaching solution and the first slag phase are obtained, and copper, nickel and arsenic enter the first leaching solution; the first leaching solution is connected to the existing copper electrolyte treatment process, and copper is removed by electrowinning, copper is enriched at the cathode, and copper is recovered; sulfur dioxide is introduced into the solution after electrowinning copper removal to reduce arsenic to obtain a reduced solution, and the reduced solution is concentrated by heating and crystallized in stages at 30°C and -20°C to recover arsenic and nickel respectively; The first slag phase is mixed with sodium carbonate and roasted to obtain a second roasted sand. The sodium salt roasting temperature is 950°C, the roasting atmosphere is O2 / (O2+N2)= 21.0%, the roasting time is 120 min, and the sodium salt ratio is 1.5. The second roasted sand is leached with alkali solution. The alkali leaching temperature is 60°C, the alkali solution is composed of NaOH with a concentration of 60 g / L, and the leaching time is 60 min to obtain a second leachate and a second slag phase. Tin enters the second leachate and is recovered by evaporation and crystallization. The second slag phase is a gold and silver enriched product (silver content 5.7%; gold content 1.1%).

[0056] The recovery rates of copper, nickel, arsenic and tin in the entire process are 93.8%, 92.2%, 92.4% and 94.6% respectively.

[0057] Example 2 Taking a certain mixed copper anode mud (metal content is Cu11.7%, As3.5%, Ni3.4%, Sn27.8%, Ag4.3%, Au0.8%) as raw material, an appropriate amount of arsenic solid agent is added and mixed and pressed into a mass, the added arsenic solid agent is copper oxide, and the molar ratio of copper in copper oxide to arsenic in mixed copper anode mud is 2, and oxidative roasting is performed to obtain the first roasted sand.

[0058] The oxidation roasting temperature is 700°C, the roasting atmosphere is O2 / (O2+N2)= 60.0%, the roasting time is 60 min, and the first roasted sand is obtained. The flue gas (arsenic content 0.8%) is recovered from the dust removal system; The first roasted sand is leached with acid solution, the leaching temperature of the acid solution is 80°C, the acid solution is composed of 150g / L sulfuric acid and 14g / L NaCl, the leaching time is 60min, and the first leaching solution and the first slag phase are obtained, and copper, nickel and arsenic enter the first leaching solution; the first leaching solution is connected to the existing copper electrolyte treatment process, and copper is removed by electrowinning, copper is enriched at the cathode, and copper is recovered; sulfur dioxide is introduced into the solution after electrowinning copper removal to reduce arsenic to obtain a reduced solution, and the reduced solution is concentrated by heating and crystallized in stages at 30°C and -20°C to recover arsenic and nickel respectively; The first slag phase is mixed with sodium carbonate and roasted to obtain a second roasted sand, the sodium salt roasting temperature is 900°C, the roasting atmosphere is O2 / (O2+N2)=15.0%, the roasting time is 60min, and the sodium salt ratio is 2; the second roasted sand is leached with alkali solution, the alkali leaching temperature is 80°C, the alkali solution is composed of NaOH with a concentration of 40g / L, the leaching time is 60min, and a second leachate and a second slag phase are obtained, tin enters the second leachate, and the tin is recovered by evaporation and crystallization. The second slag phase is a gold and silver enriched product (silver content 48.7%; gold content 1.6%).

[0059] The recovery rates of copper, nickel, arsenic and tin in the entire process are 97.5%, 95.2%, 97.4% and 98.6% respectively.

[0060] Embodiment 3: Taking a certain mixed copper anode mud (metal content of Cu13.7%, As5.4%, As5.4%, Ni4.3%, Sn19.7%, Ag8.3%, Au0.5%) as raw material, an appropriate amount of arsenic solid agent was added and mixed and pressed into a mass. The added arsenic solid agent was copper oxide and copper peroxide. The molar ratio of copper in the arsenic solid agent to arsenic in the mixed copper anode mud was 1.5. Oxidative roasting was carried out to obtain the first roasted sand.

[0061] The oxidation roasting temperature is 750°C, the roasting atmosphere is O2 / (O2+N2)= 50.0%, the roasting time is 45 minutes, and the first roasted sand is obtained. The flue gas (arsenic content 1.2%) is recovered from the dust removal system; The first roasted sand is leached with acid solution, the leaching temperature of the acid solution is 80°C, the acid solution is composed of 200g / L sulfuric acid and 12g / L NaCl, the leaching time is 60min, and the first leaching solution and the first slag phase are obtained, and copper, nickel and arsenic enter the first leaching solution; the first leaching solution is connected to the existing copper electrolyte treatment process, and copper is removed by electrowinning, copper is enriched at the cathode, and copper is recovered; sulfur dioxide is introduced into the solution after electrowinning copper removal to reduce arsenic to obtain a reduced solution, and the reduced solution is concentrated by heating and crystallized in stages at 30°C and -20°C to recover arsenic and nickel respectively; The first slag phase is mixed with sodium carbonate and roasted to obtain a second roasted sand, the sodium salt roasting temperature is 900°C, the roasting atmosphere is O2 / (O2+N2)=21.0%, the roasting time is 60min, and the sodium salt ratio is 1.5; the second roasted sand is leached with alkali solution, the alkali leaching temperature is 80°C, the alkali solution is composed of NaOH with a concentration of 80g / L, the leaching time is 45min, and a second leachate and a second slag phase are obtained, tin enters the second leachate, and the tin is recovered by evaporation and crystallization. The second slag phase is a gold and silver enriched product (silver content 40.1%; gold content 2.2%).

[0062] The recovery rates of copper, nickel, arsenic and tin in the entire process are 96.4%, 93.7%, 96.9% and 96.5% respectively.

[0063] Embodiment 4: Taking certain mixed copper anode mud (Cu21.7%, As7.9%, Ni3.0%, Sn22.4%, Ag9.4%, Au0.2%) as raw material, an appropriate amount of arsenic solid agent was added and mixed and pressed into a mass. The added arsenic solid agent was lead oxide and copper peroxide. The molar ratio of the sum of the metal elements in the arsenic solid agent to the arsenic in the mixed copper anode mud was 3.5. Oxidative roasting was carried out to obtain the first roasted sand.

[0064] The oxidation roasting temperature is 700°C, the roasting atmosphere is O2 / (O2+N2)= 55.0%, the roasting time is 60 min, and the first roasted sand is obtained. The flue gas (arsenic content 1.2%) is recovered from the dust removal system; The first roasted sand is leached with acid solution, the acid solution leaching temperature is 80°C, the acid solution is composed of 150g / L sulfuric acid and 13g / L NaCl, the leaching time is 60min, and the first leaching solution and the first slag phase are obtained, and copper, nickel and arsenic enter the first leaching solution; the first leaching solution is connected to the existing copper electrolyte treatment process, and copper is removed by electrowinning, copper is enriched at the cathode, and copper is recovered; sulfur dioxide is introduced into the solution after electrowinning copper removal to reduce arsenic to obtain a reduced solution, and the reduced solution is concentrated by heating and crystallized in stages at 30°C and -20°C to recover arsenic and nickel respectively; The first slag phase is mixed with sodium carbonate and roasted to obtain a second roasted sand, the sodium salt roasting temperature is 900°C, the roasting atmosphere is O2 / (O2+N2)=18.0%, the roasting time is 60min, and the sodium salt ratio is 1.5; the second roasted sand is leached with alkali solution, the alkali leaching temperature is 80°C, the alkali solution is composed of NaOH with a concentration of 80g / L, the leaching time is 45min, and a second leachate and a second slag phase are obtained, tin enters the second leachate, and the tin is recovered by evaporation and crystallization. The second slag phase is a gold and silver enriched product (silver content 45.1%; gold content 0.9%).

[0065] The recovery rates of copper, nickel, arsenic and tin in the entire process are 98.3%, 95.6%, 97.3% and 98.4% respectively.

[0066] Comparative Example Oxidative roasting was carried out using a certain mixed copper anode mud (Cu10.7%, As4.9%, Ni7.0%, Sn12.4%, Ag4.4%, Au0.1%) as raw material.

[0067] The first stage of calcination was carried out at a temperature of 650°C, a calcination atmosphere of O2 / (O2+N2)= 22.0%, and a calcination time of 60 min to obtain the first calcined material, and the flue gas (arsenic content 12.2%) was recovered from the dust removal system; The temperature of the second-stage acid leaching is 80°C, the acid solution is sulfuric acid with a concentration of 100g / L, and the leaching time is 60min, to obtain the first leaching solution and the first slag phase, and copper, nickel and arsenic enter the first leaching solution; the first leaching solution is connected to the existing copper electrolyte treatment process, and copper is removed by electrowinning, copper is enriched at the cathode, and copper is recovered; sulfur dioxide is introduced into the solution after electrowinning copper removal to reduce arsenic to obtain a reduced solution, and the reduced solution is concentrated by heating and crystallized in stages at 30°C and -20°C to recover arsenic and nickel respectively; The third-stage sodium salt roasting temperature is 800℃, the roasting atmosphere is O2 / (O2+N2)=21.0%, the roasting time is 60min, and the sodium salt ratio is 2; the second-stage alkali leaching temperature is 80℃, the alkali solution is composed of NaOH with a concentration of 40g / L, the leaching time is 45min, and the second leachate and the second slag phase are obtained. Tin enters the second leachate and is recovered by evaporation and crystallization. The second slag phase is a gold and silver enriched product (silver content 12.1%; gold content 0.4%).

[0068] The recovery rates of copper, nickel, arsenic and tin in the entire process are 95.3%, 90.1%, 88.3% and 93.4% respectively.

[0069] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for cascade separation and recovery of valuable metals from copper anode mud, characterized in that: The steps include: S1. Evenly mix the copper anode mud and the arsenic-fixing agent, and form agglomerates by pressing the agglomerates; the arsenic-fixing agent comprises metal oxides and / or metal peroxides; S2, oxidatively roasting the agglomerate to obtain first roasted sand; S3, leaching the first roasted sand with an acid solution to obtain a first leachate and a first slag phase, and recovering copper, nickel, and arsenic in the first leachate respectively; S4, mixing the first slag phase with sodium salt and then roasting to obtain second roasted sand; S5. Leaching the second roasted sand with an alkali solution to obtain a second leachate and a second slag phase, recovering tin in the second leachate by evaporation and crystallization, wherein the second slag phase is a gold-silver enriched slag.

2. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: The molar ratio of the sum of the metal elements in the arsenic-fixing agent to the arsenic contained in the mixed copper anode mud is 1.5-3.

5.

3. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: The arsenic-fixing agent includes one or more of copper oxide, nickel oxide, lead oxide, copper peroxide, nickel peroxide, and lead peroxide.

4. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: The conditions for the oxidation roasting in step S2 are: a temperature of 400-800° C. and a roasting time of 30 min-180 min.

5. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 4, characterized in that: When the arsenic solid agent is a metal oxide, an oxygenating agent is added during the oxidation roasting process. The oxygenating agent includes oxygen, and the volume percentage concentration of oxygen in the oxidation roasting atmosphere is controlled to be 25% to 80%.

6. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: In step S3, the solid-liquid ratio of the first roasted sand to the acid solution is 1 g: (4-10) mL; the acid solution includes 80-250 g / L H2SO4, 5-25 g / L Cl - ; The acid leaching temperature is 45~90℃, and the leaching time is 1~4h.

7. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: The sodium salt roasting conditions are as follows: the temperature is 850-1050° C., the volume percentage concentration of oxygen in the roasting atmosphere is 0.5%-21%, the amount of sodium salt added is 1.2-2.5 times the molar ratio of the tin content, and the roasting time is 30 min-120 min.

8. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 7, characterized in that: The sodium salt includes one or more of sodium carbonate, sodium hydroxide and sodium bicarbonate.

9. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: In step S5, the alkali solution is a 40-240 g / L NaOH solution, and the alkali solution leaching conditions are: the solid-liquid ratio of the second roasted sand to the alkali solution is 1 g: (8-20) mL, the temperature is 55-90° C., and the leaching time is 2-6 h.

10. The method for cascade separation and recovery of valuable metals from miscellaneous copper anode mud according to claim 1, characterized in that: The gold and silver enriched slag is used as an alchemical raw material and enters into the gold and silver pyrometallurgical smelting process.

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