Method for preparing rhodium oxide from silver anode slime byproduct
By preparing rhodium oxide from silver anode mud by-products, the existing rhodium refining process is solved, and the effects of simplification of process, increase yield and shorten production cycle are achieved.
Patent Information
- Application Number
- CN202411659827.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-03-28
AI Technical Summary
In the existing platinum group precious metals hydrometallurgy process, the refining process of rhodium is complex, the process flow is long, difficult to operate, and the metal yield is low, which seriously restricts production.
A method for preparing rhodium oxide from silver anode mud byproducts is proposed, including four main processes: pretreatment, enrichment, dissolution and preparation. Through specific chemical reactions and treatment steps, rhodium oxide is efficiently extracted from silver anode mud byproducts.
This method simplifies the process flow, improves the refining yield of rhodium, is economical and environmentally friendly, and shortens the production cycle, achieving efficient preparation of rhodium oxide.
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Figure CN119706979A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of precious metal hydrometallurgy, and in particular relates to a method for preparing rhodium oxide from silver anode mud byproducts. Background Art
[0002] The statements in this section are merely intended to provide background information related to the technical solution of the present application to aid understanding, and they do not necessarily constitute prior art for the technical solution of the present application.
[0003] In the process of wet refining of platinum group precious metals, the refining of rhodium is particularly complicated. Most of the extraction of mineral metal rhodium comes from the smelting complex of metal platinum. Its extraction methods include sodium nitrite complexation method and ammoniation method. Rhodium is extracted from the byproduct of gold extraction from silver anode mud. Because it contains high gold and silver and trace amounts of platinum group metal rhodium, the original process needs to use more conventional iron powder and copper powder replacement to produce rhodium concentrate with high iron and copper content, and then chlorinate with aqua regia or aqueous solution to make liquid and extract rhodium. The separation of noble and cheap metals needs to be achieved through medium-temperature chlorination followed by solvent extraction and ion exchange. The above traditional methods have problems such as long process flow, difficult operation, and low metal yield, which seriously restrict production. Therefore, it is extremely important to explore new processing technology, shorten the production cycle of rhodium, and improve the refining yield of rhodium. Summary of the invention
[0004] To solve the above problems, the present invention provides a method for preparing rhodium oxide from silver anode mud by-product, and its process route includes four main processes of "pretreatment-enrichment-dissolution-preparation", which can realize the efficient preparation of rhodium oxide from silver anode mud by-product.
[0005] One aspect of the present application relates to a method for preparing rhodium oxide from silver anode mud byproduct, comprising:
[0006] (1) Pretreatment: The waste liquid generated in the process of extracting gold from silver anode mud is concentrated, and then hydroxylamine hydrochloride is added at a rate of 20 to 80 g / L according to the volume of the concentrated waste liquid, and the mixture is reacted at 80 to 90° C. for 1 to 2 hours, and the first pretreatment liquid is obtained by solid-liquid separation. Then, dimethyl dithiocarbamate is added at a rate of 5 to 15 g / L according to the volume of the first pretreatment liquid, and the mixture is reacted at 50 to 60° C. for 0.5 to 1 hour, and the second pretreatment liquid is obtained by solid-liquid separation;
[0007] (2) Enrichment: adding one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate to the second pretreatment liquid obtained in step (1) to react, the addition end point is pH=13, then slowly adding 30% hydrogen peroxide solution and 20% sodium chlorate solution at 75-85° C., the volume ratio of the two added is hydrogen peroxide solution: sodium chlorate solution=1:3, the reaction end point is pH=8, then standing, solid-liquid separation, to obtain rhodium-rich material;
[0008] (3) Dissolving: For the rhodium-rich material obtained in step (2), add 3-6 mol / L dilute hydrochloric acid solution at a solid-liquid mass ratio of 1:3-8, boil and dissolve to obtain a rhodium-containing solution, add gelatin at 0.3-0.8 g / L according to the volume of the rhodium-containing solution, react at 50-60° C. for 0.5-1 h, filter to obtain a first rhodium-containing filtrate, adjust the pH of the first rhodium-containing filtrate to 0.5-1 with ammonia water, separate the solid and liquid, and obtain a second rhodium-containing filtrate;
[0009] (4) Preparation: ammonium chloride is prepared into a saturated solution, the amount of the saturated ammonium chloride solution being 5 times the volume of the second rhodium-containing filtrate, polyethylene glycol is added according to the volume of the saturated ammonium chloride solution at a rate of 1 to 10 g / L, and the mixture is stirred and mixed to obtain an ammonium chloride mixed solution, the ammonium chloride mixed solution is evaporated and crystallized in an evaporator to precipitate mixed supersaturated ammonium chloride crystals, the second rhodium-containing filtrate obtained in step (3) is heated to 80 to 85° C., and is slowly and evenly added to the evaporator while being stirred to allow the mixed supersaturated ammonium chloride crystals to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and then calcined in a muffle furnace to obtain rhodium oxide.
[0010] In one embodiment, the concentrating the waste liquid generated in the process of extracting gold from silver anode mud includes: concentrating the waste liquid to 1 / 4 of the original volume.
[0011] In one embodiment, the components of the waste liquid generated in the process of extracting gold from silver anode mud include: Ag 0.05-5g / L, Au 0.05-5g / L, Pd 0.05-2g / L, Pt 0.05-2g / L, Rh 0.05-15g / L, Ni 0.05-10g / L, Cu 0.05-10g / L, Fe 0.05-5g / L, Co 0.05-10g / L, Pb 0.05-10g / L, Se 0.05-10g / L, Te 0.05-10g / L, and Bi 0.05-10g / L.
[0012] In one embodiment, the dimethyldithiocarbamate includes one or more of sodium dimethyldithiocarbamate, potassium dimethyldithiocarbamate, and zinc dimethyldithiocarbamate.
[0013] In one embodiment, the dropping speed of the sodium chlorate solution is 20-40 L / h.
[0014] In one embodiment, ammonium chloride is prepared into a 27% saturated solution, and the saturated ammonium chloride solution is filtered to remove impurities.
[0015] In one embodiment, ammonium chlororhodate is calcined in a muffle furnace at 600-680° C. for 6-10 hours to obtain rhodium oxide.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] 1. The above-mentioned method for preparing rhodium oxide from silver anode mud by-product breaks through the original process limitations, and the process flow is simple, economical, environmentally friendly, convenient and effective.
[0018] 2. The above method for preparing rhodium oxide from silver anode mud by-product can stably prepare rhodium oxide from silver anode mud by-product, thereby simplifying the subsequent rhodium refining process. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The embodiments of the present invention are further described below with reference to the accompanying drawings, in which:
[0020] Figure 1 is a flow chart of a method for preparing rhodium oxide from silver anode mud byproduct according to one embodiment. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0022] Figure 1 The present invention is a flow chart of a method for preparing rhodium oxide from a silver anode mud byproduct according to an embodiment, which shows a method for preparing rhodium oxide from a silver anode mud byproduct, comprising the following steps:
[0023] (1) Pretreatment: The waste liquid generated in the process of extracting gold from silver anode mud is concentrated, and then hydroxylamine hydrochloride is added at a rate of 20 to 80 g / L according to the volume of the concentrated waste liquid, and the mixture is reacted at 80 to 90° C. for 1 to 2 hours, and the first pretreatment liquid is obtained by solid-liquid separation. Then, dimethyl dithiocarbamate is added at a rate of 5 to 15 g / L according to the volume of the first pretreatment liquid, and the mixture is reacted at 50 to 60° C. for 0.5 to 1 hour, and the second pretreatment liquid is obtained by solid-liquid separation;
[0024] (2) Enrichment: adding one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate to the second pretreatment liquid obtained in step (1) to react, the addition end point is pH=13, then slowly adding 30% hydrogen peroxide solution and 20% sodium chlorate solution at 75-85° C., the volume ratio of the two added is hydrogen peroxide solution: sodium chlorate solution=1:3, the reaction end point is pH=8, then standing, solid-liquid separation, to obtain rhodium-rich material;
[0025] (3) Dissolving: For the rhodium-rich material obtained in step (2), add 3-6 mol / L dilute hydrochloric acid solution at a solid-liquid mass ratio of 1:3-8, boil and dissolve to obtain a rhodium-containing solution, add gelatin at 0.3-0.8 g / L according to the volume of the rhodium-containing solution, react at 50-60° C. for 0.5-1 h, filter to obtain a first rhodium-containing filtrate, adjust the pH of the first rhodium-containing filtrate to 0.5-1 with ammonia water, separate the solid and liquid, and obtain a second rhodium-containing filtrate;
[0026] (4) Preparation: ammonium chloride is prepared into a saturated solution, the amount of the saturated ammonium chloride solution being 5 times the volume of the second rhodium-containing filtrate, polyethylene glycol is added according to the volume of the saturated ammonium chloride solution at a rate of 1 to 10 g / L, and the mixture is stirred and mixed to obtain an ammonium chloride mixed solution, the ammonium chloride mixed solution is evaporated and crystallized in an evaporator to precipitate mixed supersaturated ammonium chloride crystals, the second rhodium-containing filtrate obtained in step (3) is heated to 80 to 85° C., and is slowly and evenly added to the evaporator while being stirred to allow the mixed supersaturated ammonium chloride crystals to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and then calcined in a muffle furnace to obtain rhodium oxide.
[0027] In one embodiment, the concentrating the waste liquid generated in the process of extracting gold from silver anode mud comprises concentrating the waste liquid to 1 / 3 to 1 / 5 of the original volume, for example, about 1 / 4.
[0028] In one embodiment, the dimethyldithiocarbamate includes one or more of sodium dimethyldithiocarbamate, potassium dimethyldithiocarbamate, and zinc dimethyldithiocarbamate.
[0029] In one embodiment, the dropping speed of the sodium chlorate solution is 20-40 L / h.
[0030] In one embodiment, ammonium chloride is prepared into a 27% saturated solution, and the saturated ammonium chloride solution is filtered to remove impurities.
[0031] In one embodiment, ammonium chlororhodate is calcined in a muffle furnace at 600-680° C. for 6-10 hours to obtain rhodium oxide.
[0032] In one embodiment, the silver anode mud byproduct used in this experiment can be waste liquid generated in the process of extracting gold from silver anode mud. In one embodiment, its components include: Ag 0.05-5g / L, Au 0.05-5g / L, Pd 0.05-2g / L, Pt 0.05-2g / L, Rh 0.05-15g / L, Ni 0.05-10g / L, Cu 0.05-10g / L, Fe 0.05-5g / L, Co 0.05-10g / L, Pb 0.05-10g / L, Se 0.05-10g / L, Te 0.05-10g / L, Bi 0.05-10g / L.
[0033] In one embodiment, the specific composition of the waste liquid generated in the process of extracting gold from silver anode mud is shown in Table 1 below.
[0034] Table 1 Main components of silver anode mud by-products
[0035]
[0036] Example 1
[0037] (1) Pretreatment: 1000L of gold waste liquid extracted from silver anode mud was concentrated to 250L, and then 7500g of hydroxylamine hydrochloride was added, and the mixture was reacted at 85°C for 1h. After solid-liquid separation, a first pretreatment liquid of 213L was obtained. Then, 2550g of dimethyl dithiocarbamate was added to the first pretreatment liquid, and the mixture was reacted at 58°C for 0.5h. After solid-liquid separation, a second pretreatment liquid of 198L was obtained.
[0038] (2) Enrichment: Add sodium hydroxide, potassium hydroxide and sodium carbonate to the second pretreatment liquid obtained in step (1) until the end point pH = 13, slowly add 30% hydrogen peroxide solution and 20% sodium chlorate solution at 78°C, the addition ratio is hydrogen peroxide solution: sodium chlorate solution = 1:3, the sodium chlorate solution is added at a rate of 30 L / h, react until pH = 8, stop adding reagents, let stand for 2 hours, separate the solid and liquid, and obtain 4950 g of rhodium-rich material.
[0039] (3) Dissolution: For the rhodium-rich material obtained in step (2), add 29.7 L of 4 mol / L dilute hydrochloric acid solution at a solid-liquid ratio of 1:6, boil and dissolve to obtain a rhodium-containing solution, add 14.85 g of gelatin to the rhodium-containing solution, react at 60° C. for 1 h, filter to obtain a first rhodium-containing filtrate, add ammonia water to the rhodium-containing filtrate to adjust the system pH to 0.5, separate the solid and liquid, and obtain a second rhodium-containing filtrate totaling 28 L.
[0040] (4) Preparation: Prepare 140 L of a 27% saturated ammonium chloride solution, filter to remove impurities, add 210 g of polyethylene glycol, stir and mix to obtain an ammonium chloride mixed solution, evaporate the ammonium chloride mixed solution in an evaporator to crystallize mixed supersaturated ammonium chloride crystals, heat the second rhodium-containing filtrate obtained in step (3) to 81° C., slowly and evenly add it to the evaporator while stirring to allow it to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and calcine it at 650° C. in a muffle furnace for 8 h to obtain 235.125 g of rhodium oxide.
[0041] Example 2
[0042] (1) Pretreatment: 2500L of gold waste liquid extracted from silver anode mud was concentrated to 525L, and then 21000g of hydroxylamine hydrochloride was added, and the mixture was reacted at 83°C for 1.5h. After solid-liquid separation, a first pretreatment liquid of 480L was obtained. Then, 5760g of dimethyl dithiocarbamate was added to the first pretreatment liquid, and the mixture was reacted at 56°C for 1h. After solid-liquid separation, a second pretreatment liquid of 423L was obtained.
[0043] (2) Enrichment: Add sodium hydroxide to the second pretreatment liquid obtained in step (1) until the end point pH = 13, slowly add 30% hydrogen peroxide solution and 20% sodium chlorate solution at 83°C, the addition ratio is hydrogen peroxide solution: sodium chlorate solution = 1:3, the sodium chlorate addition rate is 35L / h, react until pH = 8, stop adding reagents, let stand for 2h, separate the solid and liquid, and obtain 11385g of rhodium-rich material.
[0044] (3) Dissolution: For the rhodium-rich material obtained in step (2), add 56.9 L of 6 mol / L dilute hydrochloric acid solution at a solid-liquid ratio of 1:5, boil and dissolve to obtain a rhodium-containing solution, add 34.15 g of gelatin to the rhodium-containing solution, react at 55° C. for 0.5 h, filter to obtain a first rhodium-containing filtrate, add ammonia water to the rhodium-containing filtrate to adjust the system pH to 1, separate the solid and liquid, and obtain a second rhodium-containing filtrate totaling 53 L.
[0045] (4) Preparation: Prepare 265 L of a 27% saturated ammonium chloride solution, filter to remove impurities, add 1325 g of polyethylene glycol, stir and mix to obtain an ammonium chloride mixed solution, evaporate the ammonium chloride mixed solution in an evaporator to crystallize mixed supersaturated ammonium chloride crystals, heat the second rhodium-containing filtrate obtained in step (3) to 82° C., slowly and evenly add it to the evaporator while stirring to allow it to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and calcine it in a muffle furnace at 670° C. for 8 h to obtain 596.747 g of rhodium oxide.
[0046] Example 3
[0047] (1) Pretreatment: 2000L of gold waste liquid extracted from silver anode mud was concentrated to 500L, and then 17500g of hydroxylamine hydrochloride was added, and the mixture was reacted at 89°C for 1h. The solid-liquid separation was performed to obtain a first pretreatment liquid of 425L in total. 4250g of dimethyl dithiocarbamate was further added to the first pretreatment liquid, and the mixture was reacted at 60°C for 1h. The solid-liquid separation was performed to obtain a second pretreatment liquid of 390L in total.
[0048] (2) Enrichment: Add sodium hydroxide, potassium hydroxide, sodium carbonate and sodium bicarbonate to the second pretreatment liquid obtained in step (1) until the end point pH = 13, slowly add 30% hydrogen peroxide solution and 20% sodium chlorate solution at 78°C, the addition ratio is hydrogen peroxide solution: sodium chlorate solution = 1:3, the sodium chlorate addition rate is 28L / h, react until pH = 8, stop adding reagents, let stand for 2h, separate solid and liquid, and obtain 9875g of rhodium-rich material.
[0049] (3) Dissolution: For the rhodium-rich material obtained in step (2), add 79 L of 6 mol / L dilute hydrochloric acid solution at a solid-liquid ratio of 1:8, boil and dissolve to obtain a rhodium-containing solution, add 47.4 g of gelatin to the rhodium-containing solution, react at 55° C. for 0.5 h, filter to obtain a first rhodium-containing filtrate, add ammonia water to the rhodium-containing filtrate to adjust the system pH to 1, separate the solid and liquid, and obtain a second rhodium-containing filtrate totaling 71 L.
[0050] (4) Preparation: Prepare 355 L of a 27% saturated ammonium chloride solution, filter to remove impurities, add 2840 g of polyethylene glycol, stir and mix to obtain an ammonium chloride mixed solution, evaporate the ammonium chloride mixed solution in an evaporator to crystallize mixed supersaturated ammonium chloride crystals, heat the second rhodium-containing filtrate obtained in step (3) to 82° C., slowly and evenly add it to the evaporator while stirring to allow it to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and calcine it in a muffle furnace at 630° C. for 8 h to obtain 505.518 g of rhodium oxide.
[0051] Example 4
[0052] (1) Pretreatment: 1000L of gold waste liquid extracted from silver anode mud was concentrated to 250L, and then 6000g of hydroxylamine hydrochloride was added, and the mixture was reacted at 85°C for 2h. After solid-liquid separation, a first pretreatment liquid of 213L was obtained. 1200g of dimethyl dithiocarbamate was further added to the first pretreatment liquid, and the mixture was reacted at 52°C for 1h. After solid-liquid separation, a second pretreatment liquid of 196L was obtained.
[0053] (2) Enrichment: Add sodium hydroxide, potassium hydroxide and sodium carbonate to the second pretreatment liquid obtained in step (1) until the end point pH = 13, slowly add 30% hydrogen peroxide solution and 20% sodium chlorate solution at 83°C, the addition ratio is hydrogen peroxide solution: sodium chlorate solution = 1:3, the sodium chlorate solution is added at a rate of 30 L / h, react until pH = 8, stop adding reagents, let stand for 2 hours, separate the solid and liquid, and obtain 4945 g of rhodium-rich material.
[0054] (3) Dissolution: For the rhodium-rich material obtained in step (2), add 3 mol / L dilute hydrochloric acid solution at a solid-liquid ratio of 1:3, boil and dissolve to obtain a rhodium-containing solution, add 5 g of gelatin to the rhodium-containing solution, react at 50°C for 1 h, filter to obtain a first rhodium-containing filtrate, add ammonia water to the rhodium-containing filtrate to adjust the system pH to 1, separate the solid and liquid, and obtain a second rhodium-containing filtrate totaling 27 L.
[0055] (4) Preparation: Prepare 135 L of 27% saturated ammonium chloride solution, filter to remove impurities, add 160 g of polyethylene glycol, stir and mix to obtain an ammonium chloride mixed solution, evaporate the ammonium chloride mixed solution in an evaporator to crystallize mixed supersaturated ammonium chloride crystals, heat the second rhodium-containing filtrate obtained in step (3) to 81° C., slowly and evenly add it to the evaporator while stirring to allow it to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and calcine it at 600° C. in a muffle furnace for 10 h to obtain 235 g of rhodium oxide.
[0056] Example 5
[0057] (1) Pretreatment: 1000L of gold waste liquid extracted from silver anode mud was concentrated to 250L, and then 18000g of hydroxylamine hydrochloride was added, and the mixture was reacted at 85°C for 1h. The solid-liquid separation was performed to obtain a first pretreatment liquid of 213L in total. 3000g of dimethyl dithiocarbamate was further added to the first pretreatment liquid, and the mixture was reacted at 60°C for 0.5h. The solid-liquid separation was performed to obtain a second pretreatment liquid of 200L in total.
[0058] (2) Enrichment: Add sodium hydroxide, potassium hydroxide and sodium carbonate to the second pretreatment liquid obtained in step (1) until the end point pH = 13, slowly add 30% hydrogen peroxide solution and 20% sodium chlorate solution at 75° C., the dropwise addition ratio is hydrogen peroxide solution: sodium chlorate solution = 1:3, the sodium chlorate solution dropwise addition rate is 30 L / h, react until pH = 8, stop adding reagents, let stand for 2 h, separate solid and liquid, and obtain 4955 g of rhodium-rich material.
[0059] (3) Dissolution: For the rhodium-rich material obtained in step (2), add 6 mol / L dilute hydrochloric acid solution at a solid-liquid ratio of 1:8, boil and dissolve to obtain a rhodium-containing solution, add 28 g of gelatin to the rhodium-containing solution, react at 60°C for 0.5 h, filter to obtain a first rhodium-containing filtrate, add ammonia water to the rhodium-containing filtrate to adjust the system pH to 0.5, separate the solid and liquid, and obtain a second rhodium-containing filtrate totaling 30 L.
[0060] (4) Preparation: Prepare 150 L of a 27% saturated ammonium chloride solution, filter to remove impurities, add 1300 g of polyethylene glycol, stir and mix to obtain an ammonium chloride mixed solution, evaporate the ammonium chloride mixed solution in an evaporator to crystallize mixed supersaturated ammonium chloride crystals, heat the second rhodium-containing filtrate obtained in step (3) to 85° C., slowly and evenly add it to the evaporator while stirring to allow it to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and calcine it in a muffle furnace at 680° C. for 6 h to obtain 235.3 g of rhodium oxide.
[0061] References herein to "various embodiments", "some embodiments", "one embodiment" or "an embodiment" etc. refer to that a particular feature, structure or property described in conjunction with the embodiment is included in at least one embodiment. Therefore, the phrases "in various embodiments", "in some embodiments", "in one embodiment" or "in an embodiment" etc. appearing throughout this document do not necessarily refer to the same embodiment. In addition, particular features, structures or properties may be combined in any suitable manner in one or more embodiments. Therefore, the particular features, structures or properties shown or described in conjunction with one embodiment may be combined in whole or in part with features, structures or properties of one or more other embodiments without restriction, as long as the combination is not illogical or inoperable. Expressions similar to "according to A", "based on A", "through A" or "using A" appearing herein are intended to be non-exclusive, that is, "according to A" may cover "according to A only" or "according to A and B", unless it is specifically stated that its meaning is "according to A only". In this application, for the sake of clarity, some exemplary operating steps are described in a certain order, but those skilled in the art will understand that each of these operating steps is not essential, and some of the steps may be omitted or replaced by other steps. These operation steps do not have to be executed sequentially in the manner shown; on the contrary, some of these operation steps can be executed in different orders or in parallel according to actual needs, as long as the new execution manner is not illogical or inoperable.
[0062] Some exemplary embodiments of the present invention are described above. It can be understood that the above embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention. The features in these embodiments can be recombined in a suitable manner, and the scheme obtained thereby is still within the protection scope required by the present invention. Based on the above embodiments, all other embodiments obtained by those skilled in the art without making creative work, that is, all modifications, equivalent substitutions and improvements made within the spirit and principles of this application, fall within the protection scope required by the present invention.
Claims
1. A method for preparing rhodium oxide from silver anode mud byproducts, comprising: (1) Pretreatment: The waste liquid generated in the process of extracting gold from silver anode mud is concentrated, and then hydroxylamine hydrochloride is added at a rate of 20 to 80 g / L according to the volume of the concentrated waste liquid, and the mixture is reacted at 80 to 90° C. for 1 to 2 hours, and the first pretreatment liquid is obtained by solid-liquid separation. Then, dimethyl dithiocarbamate is added at a rate of 5 to 15 g / L according to the volume of the first pretreatment liquid, and the mixture is reacted at 50 to 60° C. for 0.5 to 1 hour, and the second pretreatment liquid is obtained by solid-liquid separation; (2) Enrichment: adding one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate to the second pretreatment liquid obtained in step (1) to react, the addition end point is pH=13, then slowly adding 30% hydrogen peroxide solution and 20% sodium chlorate solution at 75-85° C., the volume ratio of the two added is hydrogen peroxide solution: sodium chlorate solution=1:3, the reaction end point is pH=8, then standing, solid-liquid separation, to obtain rhodium-rich material; (3) Dissolving: For the rhodium-rich material obtained in step (2), add 3-6 mol / L dilute hydrochloric acid solution at a solid-liquid mass ratio of 1:3-8, boil and dissolve to obtain a rhodium-containing solution, add gelatin at 0.3-0.8 g / L according to the volume of the rhodium-containing solution, react at 50-60° C. for 0.5-1 h, filter to obtain a first rhodium-containing filtrate, adjust the pH of the first rhodium-containing filtrate to 0.5-1 with ammonia water, separate the solid and liquid, and obtain a second rhodium-containing filtrate; (4) Preparation: ammonium chloride is prepared into a saturated solution, the amount of the saturated ammonium chloride solution being 5 times the volume of the second rhodium-containing filtrate, polyethylene glycol is added according to the volume of the saturated ammonium chloride solution at a rate of 1 to 10 g / L, and the mixture is stirred and mixed to obtain an ammonium chloride mixed solution, the ammonium chloride mixed solution is evaporated and crystallized in an evaporator to precipitate mixed supersaturated ammonium chloride crystals, the second rhodium-containing filtrate obtained in step (3) is heated to 80 to 85° C., and is slowly and evenly added to the evaporator while being stirred to allow the mixed supersaturated ammonium chloride crystals to fully react with the mixed supersaturated ammonium chloride crystals to obtain pure ammonium chlororhodate, and then calcined in a muffle furnace to obtain rhodium oxide.
2. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: The method of concentrating the waste liquid generated in the process of extracting gold from silver anode mud comprises: concentrating the waste liquid to 1 / 4 of the original volume.
3. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: The components of the waste liquid generated in the process of extracting gold from silver anode mud include: Ag 0.05-5g / L, Au 0.05-5g / L, Pd 0.05-2g / L, Pt 0.05-2g / L, Rh 0.05-15g / L, Ni 0.05-10g / L, Cu 0.05-10g / L, Fe 0.05-5g / L, Co 0.05-10g / L, Pb 0.05-10g / L, Se 0.05-10g / L, Te 0.05-10g / L, and Bi 0.05-10g / L.
4. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: The dimethyldithiocarbamate salt includes one or more of sodium dimethyldithiocarbamate, potassium dimethyldithiocarbamate, and zinc dimethyldithiocarbamate.
5. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: The dropping speed of the sodium chlorate solution is 20 to 40 L / h.
6. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: Ammonium chloride was prepared into a 27% saturated solution, and the saturated ammonium chloride solution was filtered to remove impurities.
7. A method for preparing rhodium oxide from silver anode mud byproduct according to claim 1, characterized in that: Ammonium chlororhodate is calcined in a muffle furnace at 600-680°C for 6-10 hours to obtain rhodium oxide.