Method for extracting rhodium from rhodium-rich material
Through the four steps of water bath purification, oxidation liquid, amination precipitation and reduction of powder making, the problem of difficulty in efficient recycling of rhodium in the rhodium-rich material in the prior art is solved, and efficient extraction and purification of rhodium powder is achieved. The purity and impurity content of the product are both met in industrial applications.
Patent Information
- Application Number
- CN202411630989.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-03-28
AI Technical Summary
It is difficult to efficiently recover rhodium in rhodium-rich materials in the prior art, especially in rhodium-rich materials produced after extraction of platinum-rhodium alloys or platinum-palladium alloys. Traditional refining and purification processes cannot achieve efficient recovery.
Rhodium is extracted from rhodium-rich material by four steps: water bath purification, oxidation liquid, amination precipitation and reduction of powder making. Specific steps include: water bath purification to obtain rhodium concentrate, oxidation liquid increases the solubility of rhodium, amination of precipitates to achieve efficient precipitation of rhodium, and reducing the rhodium salt to metal powder through reducing powder.
The efficient extraction and purification of rhodium in rhodium-rich materials is achieved, and the impurity content of the rhodium powder produced is <0.015 wt%, meeting the purity requirements for industrial applications.
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Figure CN119710257A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of noble metal hydrometallurgy and relates to a method for extracting rhodium from rhodium-rich materials. Background Art
[0002] Platinum group metals have excellent catalytic activity, high melting point, strong chemical inertness, corrosion resistance, good ductility, stable electrothermal properties and high strength. They are widely used in many fields such as automobiles, chemicals, petroleum, electrical and electronic, jewelry and fuel cells. At present, with the rapid development of my country's economy and science and technology, the demand for platinum group metals is increasing. However, due to the extremely uneven distribution of global platinum group metal resources, my country's platinum group metal mineral resources are scarce, and there is a serious contradiction between supply and demand. Taking this as an opportunity, the recovery of platinum group metal secondary resources from failed automobile, petrochemical and other catalysts and various platinum group metal alloy wastes has become a hot spot in the industry. There are more than 200 types of such materials, with complex impurity composition and content, and stable material properties, including platinum-rhodium alloys recovered from catalysts and thermocouples. The traditional refining and purification process cannot achieve efficient recovery of rhodium in platinum-rhodium alloys or rhodium-rich materials obtained after extracting platinum and palladium from platinum-rhodium alloys. Summary of the invention
[0003] In view of the problems existing in the prior art, the present invention provides a method for extracting rhodium from a rhodium-rich material, which specifically comprises the following contents:
[0004] A method for extracting rhodium from a rhodium-rich material comprises the following steps:
[0005] S1, water bath purification: adding pure water to the rhodium-rich material for slurry treatment to obtain rhodium-rich slurry; heating the rhodium-rich material to 80-85°C, adding potassium permanganate solution as a purifier, stirring for reaction, and then cooling and filtering to obtain rhodium concentrate; the mass content of rhodium in the rhodium-rich material is ≥2%;
[0006] S2, oxidation liquid preparation: adding an oxidant solution to the rhodium concentrate to carry out an oxidation reaction to obtain a rhodium-rich solution;
[0007] S3, amination salt precipitation: heating the rhodium-rich solution and adding an oxygen amine reagent to react, and filtering after the reaction is completed to obtain a rhodium salt;
[0008] S4, reduction powder making: pure water is added to the rhodium salt to make a slurry, and then the temperature is increased, and then a reducing agent is added, and the temperature is continued to be increased and kept warm for a period of time, and finally pure rhodium powder is obtained.
[0009] Optionally, repeat steps S2-S3 two to four times, and then perform S4.
[0010] Furthermore, in step S1, the solid-liquid ratio of the rhodium-rich material and pure water is 1:(4-5); and / or the mass concentration of the potassium permanganate solution is 3-4%; and / or the amount of the potassium permanganate solution added is 25-35% of the total volume of the reaction system.
[0011] Furthermore, the oxidant solution in step S2 is a solution obtained by mixing nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution in a volume ratio of 1:(0.9-1.1):(0.9-1.1), wherein the mass concentration of the nitric acid solution is 67-69%, the mass concentration of the hydrochloric acid solution is 28-30%, and the mass concentration of the hydrogen peroxide solution is 34-36%.
[0012] Furthermore, the solid-to-liquid ratio of the rhodium concentrate to the oxidant solution in step S2 is 1:(4-6).
[0013] Furthermore, the reaction temperature of the oxidation reaction in step S2 is 70-75°C.
[0014] Furthermore, in step S3, the rhodium-rich solution is heated to boiling and then an oxygen amine reagent is added; and / or, the reaction time in step S3 is 25-35 minutes.
[0015] Furthermore, the oxygen amine reagent is an ethanol solution of polyethyleneimine with a mass concentration of 15-20%.
[0016] Further, step S4: the solid-liquid ratio of the rhodium salt to pure water is 1:(2.5-3.5); and / or, the temperature is raised to 50-55°C after slurrying; and / or, the temperature is raised to boiling of the reaction system after adding the reducing agent; and / or, the insulation time is 15-20min.
[0017] Furthermore, step S4 also includes filtering, washing and drying.
[0018] Furthermore, the reducing agent in step S4 is a hydrazine sulfate solution with a mass concentration of 7-9%; and / or, the hydrazine sulfate solution is added at a rate of 15-20 L / h until the pH of the reaction system reaches 1-1.5 and then stopped.
[0019] Beneficial effects of the present invention:
[0020] The method for extracting rhodium from rhodium-rich materials disclosed in the present invention is for rhodium-rich materials with a mass content of rhodium of ≥2%. First, a 3-4% potassium permanganate solution is used to purify the rhodium-rich material slurry, which can realize the transformation of the rhodium-rich material system and the destruction of residual organic matter, creating conditions for subsequent refining; then a mixed reagent of nitric acid, hydrochloric acid and hydrogen peroxide is used to oxidize and leach the purified rhodium concentrate, and the dissolution of rhodium in the concentrate is realized by a strong oxidant, and the oxidation potential of the system is further improved; then an ethanol solution of polyethyleneimine is used to precipitate the rhodium-rich solution, and efficient precipitation of rhodium is realized, and a stable rhodium salt is generated by the reaction of an alcohol amine reagent with rhodium ions, so as to achieve the purpose of separating rhodium from other metal impurities; finally, after the rhodium salt is slurried, a hydrazine sulfate solution is used to reduce the rhodium salt, and the rhodium salt is reduced to metal powder by the strong reducing property of hydrazine sulfate, and the speed of nucleation and growth of rhodium crystals can be realized by controlling the adding speed of the reducing agent, thereby ensuring the uniformity of the rhodium powder produced by the reduction process. It has been experimentally verified that the impurity content of the rhodium powder prepared by the method of the present invention is less than 0.015wt%. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 The present invention is a schematic diagram of the process flow of the method disclosed in the present invention. DETAILED DESCRIPTION
[0022] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments shown below do not limit the invention content described in the claims. In addition, the entire contents of the structures represented by the following embodiments are not limited to those necessary as solutions to the invention described in the claims.
[0023] Reference Figure 1 , a method for extracting rhodium from a rhodium-rich material, comprising the following steps:
[0024] S1, water bath purification: adding pure water to the rhodium-rich material at a solid-liquid ratio of 1: (4-5) for slurry treatment to obtain rhodium-rich slurry; heating the rhodium-rich material to 80-85° C. and adding a 3-4% potassium permanganate solution as a purifier, wherein the amount of the potassium permanganate solution added is 25-35% of the total volume of the reaction system, stirring the reaction, and then cooling and filtering to obtain a rhodium concentrate; the mass content of rhodium in the rhodium-rich material is ≥2%;
[0025] S2, oxidation liquid making: adding a mixed solution of nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution in a volume ratio of 1:(0.9-1.1):(0.9-1.1) to the rhodium concentrate as an oxidant, wherein the mass concentration of the nitric acid solution is 67-69%, the mass concentration of the hydrochloric acid solution is 28-30%, and the mass concentration of the hydrogen peroxide solution is 34-36%, and the solid-liquid ratio of the rhodium concentrate to the oxidant solution is controlled to be 1:(4-6), and the temperature is raised to 70-75° C. for oxidation reaction to obtain a rhodium-rich solution;
[0026] S3, amination salt precipitation: heating the rhodium-rich solution to boiling, adding a 15-20% mass concentration of polyethyleneimine ethanol solution as an oxygen amine reagent to react for 25-35 minutes, and filtering after the reaction is completed to obtain a rhodium salt;
[0027] S4, reduction powder making: pure water is added to the rhodium salt according to the solid-liquid ratio of 1: (2.5-3.5) to slurry, then the temperature is raised to 50-55°C, and then a hydrazine sulfate solution with a mass concentration of 7-9% is slowly added as a reducing agent at a rate of 15-20L / h until the pH of the reaction system is 1-1.5, then the temperature is raised to boiling, and the temperature is kept for 15-20min, filtered, washed and dried, and finally pure rhodium powder is obtained. If necessary, steps S2-S3 can be repeated two to four times, and then the operation of S4 is performed.
[0028] Example 1
[0029] A method for extracting and preparing rhodium powder from a high-grade platinum-rhodium alloy rhodium-rich material (i.e., a rhodium-rich material produced after platinum and palladium are extracted from a high-grade platinum-rhodium alloy), comprising the following steps:
[0030] S1: 50 kg of rhodium-rich material was slurried with 200 L of pure water, the temperature was raised to 80°C, 60 L of 3.5% potassium permanganate solution was slowly added, and after the addition was complete, the mixture was stirred for reaction for 30 min, cooled and filtered to obtain purified rhodium concentrate;
[0031] S2: 47.35 kg of purified rhodium concentrate obtained by filtration is slurried with 235 L of a mixed solution of nitric acid: hydrochloric acid: hydrogen peroxide in a volume ratio of 1:1:1, and then heated to 70°C for constant temperature dissolution. After complete dissolution, the rhodium-rich solution is filtered out;
[0032] S3: After boiling the obtained 201L rhodium-rich solution, add 18% polyethyleneimine ethanol solution to react for 30 minutes, and after the reaction is complete, filter to obtain rhodium salt;
[0033] Repeat S2-S3 twice and then proceed to S4: slurry the obtained 14.64 kg rhodium salt with 65 L pure water and heat to 50°C, slowly add 8% hydrazine sulfate solution until pH = 1 and boil for 18 minutes, wash the rhodium powder produced by reduction with pure water until neutral to obtain pure rhodium powder.
[0034] Using the above method, the metal content of a high-grade platinum-rhodium alloy rhodium-rich material is shown in Table 1:
[0035] Table 1 Metal content of high-grade platinum-rhodium alloy rhodium-rich materials (%)
[0036]
[0037] The content of rhodium salt after being treated with S1 once and S2-S3 twice is shown in Table 2:
[0038] Table 2 Rhodium salt content after S1 treatment once and S2-S3 treatment twice (%)
[0039]
[0040] After S4 treatment, the metal content of rhodium powder is shown in Table 3:
[0041] Table 3 Metal content of rhodium powder after S4 treatment (%)
[0042]
[0043] It can be seen from the data in the table that after the implementation of the above process, qualified rhodium powder was produced, and the mass of the produced rhodium powder was 1.65kg.
[0044] Example 2
[0045] A method for extracting rhodium from a rhodium-rich material comprises the following steps:
[0046] S1, water bath purification: pure water is added to the rhodium-rich material at a solid-liquid ratio of 1:4 for slurry treatment to obtain rhodium-rich slurry; after heating the rhodium-rich material to 80° C., a 3% potassium permanganate solution is added as a purifier, and the amount of the potassium permanganate solution added is 25% of the total volume of the reaction system, and the reaction is stirred, and then cooled and filtered to obtain a rhodium concentrate; the mass content of rhodium in the rhodium-rich material is 3.15%;
[0047] S2, oxidation liquid making: adding a mixed solution of nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution in a volume ratio of 1:0.9:0.9 to the rhodium concentrate as an oxidant, wherein the mass concentration of the nitric acid solution is 67%, the mass concentration of the hydrochloric acid solution is 28%, and the mass concentration of the hydrogen peroxide solution is 34%, and the solid-liquid ratio of the rhodium concentrate to the oxidant solution is controlled to be 1:4, and the temperature is raised to 70° C. for oxidation reaction to obtain a rhodium-rich solution;
[0048] S3, amination salt precipitation: heating the rhodium-rich solution to boiling, adding a 15% mass concentration of polyethyleneimine ethanol solution as an oxygen amine reagent to react for 25 minutes, and filtering after the reaction is completed to obtain a rhodium salt;
[0049] S4, reduction powder making: pure water is added to the rhodium salt according to a solid-liquid ratio of 1:2.5 to make a slurry, then the temperature is raised to 50°C, and then a 7% mass concentration of hydrazine sulfate solution is slowly added as a reducing agent at a rate of 15L / h until the pH of the reaction system is 1-1.2 and then stopped, then the temperature is raised to boiling and kept warm for 15 minutes, filtered, washed and dried, and finally a rhodium powder with a purity of >98.7wt% (mass percentage) is obtained.
[0050] Example 3
[0051] A method for extracting rhodium from a rhodium-rich material comprises the following steps:
[0052] S1, water bath purification: pure water is added to the rhodium-rich material at a solid-liquid ratio of 1:5 for slurry treatment to obtain rhodium-rich slurry; after heating the rhodium-rich material to 85° C., a potassium permanganate solution with a mass concentration of 4% is added as a purifier, and the amount of the potassium permanganate solution added is 35% of the total volume of the reaction system, and the reaction is stirred, and then cooled and filtered to obtain a rhodium concentrate; the mass content of rhodium in the rhodium-rich material is 3.87%;
[0053] S2, oxidation liquid making: adding a mixed solution of nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution in a volume ratio of 1:1.1:1.1 to the rhodium concentrate as an oxidant, wherein the mass concentration of the nitric acid solution is 69%, the mass concentration of the hydrochloric acid solution is 30%, and the mass concentration of the hydrogen peroxide solution is 36%, and the solid-liquid ratio of the rhodium concentrate to the oxidant solution is controlled to be 1:6, and the temperature is raised to 75° C. for oxidation reaction to obtain a rhodium-rich solution;
[0054] S3, amination salt precipitation: heating the rhodium-rich solution to boiling, adding a 20% ethanol solution of polyethyleneimine as an oxygen amine reagent to react for 35 minutes, and filtering after the reaction to obtain a rhodium salt;
[0055] S4, reduction powder making: pure water is added to the rhodium salt according to a solid-liquid ratio of 1:3.5 to make a slurry, then the temperature is raised to 55°C, and then a 9% mass concentration of hydrazine sulfate solution is slowly added as a reducing agent at a rate of 20L / h until the pH of the reaction system is 1.5 and then stopped, then the temperature is raised to boiling and kept warm for 20 minutes, and after filtering, washing and drying, rhodium powder with a purity of >99% (mass percentage) is finally obtained.
[0056] Example 4
[0057] A method for extracting rhodium from a rhodium-rich material comprises the following steps:
[0058] S1, water bath purification: pure water is added to the rhodium-rich material at a solid-liquid ratio of 1:4.5 for slurry treatment to obtain rhodium-rich slurry; after heating the rhodium-rich material to 82° C., a 3.5% potassium permanganate solution is added as a purifier, and the amount of the potassium permanganate solution added is 30% of the total volume of the reaction system, and the reaction is stirred, and then cooled and filtered to obtain a rhodium concentrate; the mass content of rhodium in the rhodium-rich material is 3.97%;
[0059] S2, oxidation liquid preparation: adding a mixed solution of nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution in a volume ratio of 1:1:1 to the rhodium concentrate as an oxidant, wherein the mass concentration of the nitric acid solution is 68%, the mass concentration of the hydrochloric acid solution is 29%, and the mass concentration of the hydrogen peroxide solution is 35%, and the solid-liquid ratio of the rhodium concentrate to the oxidant solution is controlled to be 1:5, and the temperature is raised to 72° C. for oxidation reaction to obtain a rhodium-rich solution;
[0060] S3, amination salt precipitation: heating the rhodium-rich solution to boiling, adding a polyethyleneimine ethanol solution with a mass concentration of 18% as an oxygen amine reagent to react for 30 minutes, and filtering after the reaction is completed to obtain a rhodium salt;
[0061] Repeat steps S2-S3 three times, and then proceed to S4: reduction powder making: add pure water to the rhodium salt at a solid-liquid ratio of 1:3 to slurry, then heat to 53°C, and then slowly add 8% mass concentration of hydrazine sulfate solution as a reducing agent at a rate of 18L / h until the pH of the reaction system is 1.3-1.5, then heat to boiling and keep warm for 18 minutes, filter, wash and dry, and finally obtain rhodium powder with a purity greater than 99.1% (mass percentage).
[0062] Example 5
[0063] Reference Figure 1 , a method for extracting rhodium from a rhodium-rich material, comprising the following steps:
[0064] S1, water bath purification: pure water is added to the rhodium-rich material at a solid-liquid ratio of 1:5 for slurry treatment to obtain rhodium-rich slurry; after heating the rhodium-rich material to 85° C., a potassium permanganate solution with a mass concentration of 4% is added as a purifier, and the amount of the potassium permanganate solution added is 30% of the total volume of the reaction system, and the reaction is stirred, and then cooled and filtered to obtain a rhodium concentrate; the mass content of rhodium in the rhodium-rich material is 3.53%;
[0065] S2, oxidation liquid making: adding a mixed solution of nitric acid: hydrochloric acid: hydrogen peroxide in a volume ratio of 1:1:1 to the rhodium concentrate as an oxidant, wherein the mass concentration of the nitric acid solution is 68.5%, the mass concentration of the hydrochloric acid solution is 28.5%, the mass concentration of the hydrogen peroxide solution is 34.5%, and the solid-liquid ratio of the rhodium concentrate to the oxidant solution is controlled to be 1:5), heating to 75° C. for oxidation reaction to obtain a rhodium-rich solution;
[0066] S3, amination salt precipitation: heating the rhodium-rich solution to boiling, adding a 20% ethanol solution of polyethyleneimine as an oxygen amine reagent to react for 30 minutes, and filtering after the reaction to obtain a rhodium salt;
[0067] Repeat steps S2-S3 four times, and then proceed to S4, reduction powder making: add pure water to the rhodium salt at a solid-liquid ratio of 1:3 to slurry, then heat to 55°C, and then slowly add 8% mass concentration of hydrazine sulfate solution as a reducing agent at a rate of 15L / h until the pH of the reaction system is 1-1.5 and then stop, then heat to boiling and keep warm for 20 minutes, filter, wash and dry, and finally obtain rhodium powder with a purity of >99.5% (mass percentage).
[0068] Comparative Example 1
[0069] The difference between this comparative example and Example 5 is that the reaction temperature of step S1 is 75° C., and other conditions are the same.
[0070] After testing, the purity of the rhodium powder prepared in this comparative example was 98.1%.
[0071] Comparative Example 2
[0072] The difference between this comparative example and Example 5 is that the reaction temperature of step S1 is 90° C., and other conditions are the same.
[0073] After testing, the purity of the rhodium powder prepared in this comparative example was 98.3%.
[0074] Comparative Example 3
[0075] The difference between this comparative example and Example 5 is that hydrogen peroxide is used as an oxidant in step S1, and other conditions are the same.
[0076] After testing, the purity of the rhodium powder prepared in this comparative example was 97.3%.
[0077] Comparative Example 4
[0078] The difference between this comparative example and Example 5 is that the temperature is not further increased after the reducing agent is added in step S4, and other conditions are the same.
[0079] After testing, the purity of the rhodium powder prepared in this comparative example was 96.9%.
[0080] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for extracting rhodium from a rhodium-rich material, characterized in that The following steps are involved: S1, water bath purification: adding pure water to the rhodium-rich material for slurry treatment to obtain rhodium-rich slurry; heating the rhodium-rich material to 80-85°C, adding potassium permanganate solution as a purifier, stirring for reaction, and then cooling and filtering to obtain rhodium concentrate; the mass content of rhodium in the rhodium-rich material is ≥2%; S2, oxidation liquid preparation: adding an oxidant solution to the rhodium concentrate to carry out an oxidation reaction to obtain a rhodium-rich solution; S3, amination salt precipitation: heating the rhodium-rich solution and adding an oxygen amine reagent to react, and filtering after the reaction is completed to obtain a rhodium salt; S4, reduction powder making: pure water is added to the rhodium salt to make a slurry, and then the temperature is increased, and then a reducing agent is added, and the temperature is continued to be increased and kept warm for a period of time, and finally pure rhodium powder is obtained.
2. A method for extracting rhodium from a rhodium-rich material according to claim 1, characterized in that Step S1: the solid-liquid ratio of the rhodium-rich material and pure water is 1:(4-5); and / or the mass concentration of the potassium permanganate solution is 3-4%; and / or the amount of the potassium permanganate solution added is 25-35% of the total volume of the reaction system.
3. A method for extracting rhodium from a rhodium-rich material according to claim 1, characterized in that The oxidant solution in step S2 is nitric acid solution: hydrochloric acid solution: hydrogen peroxide solution according to The solution is obtained by mixing the nitric acid solution in a volume ratio of 1:(0.9-1.1):(0.9-1.1), wherein the mass concentration of the nitric acid solution is 67-69%, the mass concentration of the hydrochloric acid solution is 28-30%, and the mass concentration of the hydrogen peroxide solution is 34-36%.
4. A method for extracting rhodium from a rhodium-rich material according to claim 3, characterized in that: The solid-to-liquid ratio of the rhodium concentrate to the oxidant solution in step S2 is 1:(4-6).
5. A method for extracting rhodium from a rhodium-rich material according to claim 4, characterized in that: The reaction temperature of the oxidation reaction in step S2 is 70-75°C.
6. A method for extracting rhodium from a rhodium-rich material according to claim 1, characterized in that Step S3: heating the rhodium-rich solution to boiling and then adding an oxygen amine reagent; and / or, the reaction time in step S3 is 25-35 minutes.
7. A method for extracting rhodium from a rhodium-rich material according to claim 6, characterized in that: The oxygen amine reagent is an ethanol solution of polyethyleneimine with a mass concentration of 15-20%.
8. A method for extracting rhodium from a rhodium-rich material according to claim 1, characterized in that Step S4: the solid-liquid ratio of the rhodium salt to pure water is 1:(2.5-3.5); and / or, the temperature is raised to 50-55°C after slurrying; and / or, the temperature is raised to boiling of the reaction system after adding a reducing agent; and / or, the insulation time is 15-20 minutes.
9. A method for extracting rhodium from a rhodium-rich material according to claim 1, characterized in that Repeat steps S2-S3 two to four times, and then proceed to step S4.
10. The method for extracting rhodium from a rhodium-rich material according to any one of claims 1 to 9, characterized in that: In step S4, the reducing agent is a hydrazine sulfate solution with a mass concentration of 7-9%; and / or, the method for adding the hydrazine sulfate solution is: adding at a rate of 15-20 L / h until the pH of the reaction system reaches 1-1.5 and then stopping the addition.