A method for purifying osmium salt by secondary distillation
Through the secondary distillation and purification method of primary osmium salt, including acid oxidation distillation, gradient absorption and sand core filtration, the problem of high impurity content during osmium distillation is solved, efficient osmium purification is achieved, and the purity of osmium powder is improved.
Patent Information
- Application Number
- CN202411630784.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-04-04
AI Technical Summary
During the existing osmium distillation process, the osmium absorbing liquid contains a large amount of impurities, resulting in low purity of osmium powder. The existing impurity removal methods are not efficient and cumbersome.
The secondary distillation and purification method of primary osmium salt is adopted, including acid oxidation distillation, gradient absorption and sand core filtration steps. Osmium is converted to osmium tetroxide by acid oxidation distillation, and the osmium salt is further purified by gradient absorption and sand core filtration.
The osmium distillation efficiency is improved, the impurity content is significantly reduced, and the purity of osmium powder is improved, so that the osmium absorber can be directly used in industrial use.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of noble metal hydrometallurgy and relates to a primary osmium salt secondary distillation purification method. Background Art
[0002] Osmium, a platinum group metal, is an important rare and precious metal in industrial development and high-tech fields. Its extraction mainly adopts the distillation-absorption method, that is, under the action of a strong oxidant, the osmium in the feed liquid is volatilized in the form of oxides, and the corresponding absorption liquid is selected for absorption, so that the separation of osmium and other precious metals can be achieved. Since the osmium distillation process involves high temperature and highly corrosive solution media, the traditional osmium distillation device is mainly a beaker, and the osmium absorption device is mainly a submerged single-tube bubbling form of multi-stage conical flasks in series. The operation process is: after the osmium-containing raw material is leached in the beaker, the temperature is increased and a strong oxidant is added for distillation. The evaporated osmium is absorbed by sodium (potassium) hydroxide in the conical flask, and the absorption liquid is reduced by sulfur dioxide to produce osmium salt. In the process of recovering osmium-containing mineral materials, the osmium absorption liquid produced by a single distillation usually contains a large amount of impurities, which cannot be directly used for industrialization or produce qualified osmium powder. The existing impurity removal method is cumbersome and inefficient, and the purity of the osmium powder finally obtained is not high. Summary of the invention
[0003] In view of the problems existing in the prior art, the present invention provides a method for purifying an osmium salt by secondary distillation, and the present invention specifically includes the following contents:
[0004] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0005] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:(2.5-3.5) and add it to a distillation device, then slowly add 8-12% sulfuric acid by total volume, stir and react; then increase the temperature and keep warm, and continuously add an oxidant during the insulation process to perform acid oxidation distillation of osmium;
[0006] S2, gradient absorption: while acid oxidation distillation is in progress, the steam generated by distillation is sequentially passed into 4 levels of absorption liquids of different concentrations for gradient absorption to obtain osmium absorption liquid;
[0007] S3, sand core filtration: collect the osmium absorption liquid and let it settle, and finally filter it using a sand core funnel to finally obtain pure osmium salt secondary distillation absorption liquid.
[0008] Furthermore, in step S1, the stirring reaction time is 10-20 minutes; and / or the insulation temperature is 90-95°C.
[0009] Furthermore, the precipitation time in step S3 is 3-5 hours.
[0010] Furthermore, the sand core hole diameter of the sand core hole in step S3 is 8-13 μm.
[0011] Furthermore, in step S1, the oxidant is a peroxyacetic acid solution with a mass concentration of 2-3%, and the peroxyacetic acid solution is added at a rate of 10-15 L / h.
[0012] Furthermore, the four levels of absorption liquids of different concentrations in step S2 are sodium formate solutions with mass concentrations of 9-11%, 7-9%, 4-6%, and 1-3%, respectively.
[0013] Beneficial effects of the present invention:
[0014] (1) The secondary distillation purification method of a primary osmium salt disclosed in the present invention comprises the following steps: slurrying the primary osmium salt with pure water at a solid-liquid ratio of 1:(2.5-3.5) and adding the slurry into a distillation device, then slowly adding sulfuric acid at a total volume of 8-12%, stirring for reaction; then raising the temperature and keeping the temperature, continuously adding an oxidant during the keeping temperature process, and performing acidic oxidation distillation of osmium. In this step, the strong oxidizing property of peracetic acid under acidic conditions is used to oxidize osmium in the system, so that all osmium is converted into osmium tetroxide for volatilization. At the same time, the high volatility of the trace amount of peracetic acid in the solution will increase the volatilization kinetic energy of osmium tetroxide and improve the distillation efficiency;
[0015] (2) The primary osmium salt secondary distillation purification method disclosed in the present invention comprises four levels of sodium formate solutions of different concentrations as absorption liquids for absorbing osmium tetroxide, wherein osmium tetroxide reacts with sodium formate in the absorption liquid to generate soluble osmium salts, and volatilized osmium tetroxide enters the solution. Meanwhile, the decomposed formic acid in the absorption liquid destroys the oxidizability of the volatile osmium tetroxide, thereby inhibiting oxidation and ensuring complete absorption.
[0016] (3) The primary osmium salt secondary distillation purification method disclosed in the present invention collects the osmium absorption liquid and precipitates it. After precipitation, it is filtered using a sand core funnel to obtain a pure osmium salt secondary distillation absorption liquid. The sand core with a pore size of 10-13 microns is used to achieve efficient filtration of salt crystals and insoluble or insoluble impurities in the absorption liquid, thereby further purifying the absorption liquid system. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 The present invention is a schematic diagram of the process flow of the method disclosed in the present invention. DETAILED DESCRIPTION
[0018] 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.
[0019] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0020] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1: (2.5-3.5) and add it to a distillation device, then slowly add 8-12% sulfuric acid by total volume, and stir to react for 10-20 minutes; then increase the temperature to 90-95°C and keep warm, and continuously add 2-3% peroxyacetic acid solution as an oxidant during the insulation process, and the addition rate of the peroxyacetic acid solution is controlled at 10-15L / h to perform acid oxidation distillation of osmium;
[0021] S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of absorption liquids with different concentrations for gradient absorption, wherein the 4 levels of absorption liquids with different concentrations are sodium formate solutions with mass concentrations of 9-11%, 7-9%, 4-6%, and 1-3%, respectively, to finally obtain an osmium absorption liquid;
[0022] S3, sand core filtration: collect the osmium absorption liquid and let it settle for 3-5 hours, and finally filter it with a sand core funnel. The pore size of the sand core hole is 8-13 μm, and finally obtain pure osmium salt secondary distillation absorption liquid.
[0023] Figure 1 is a schematic diagram of the process flow of the method disclosed in the present invention, Figure 1 Medium and high impurity osmium salts are primary osmium salts.
[0024] Example 1
[0025] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0026] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:2.5 and add it to a distillation device, then slowly add 8% sulfuric acid by total volume, and stir to react for 10 minutes; then raise the temperature to 90°C and keep warm, and continuously add 2% peroxyacetic acid solution as an oxidant during the insulation process, and the addition rate of the peroxyacetic acid solution is controlled at 10L / h to perform acid oxidation distillation of osmium;
[0027] S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of absorption liquids with different concentrations for gradient absorption, wherein the 4 levels of absorption liquids with different concentrations are sodium formate solutions with mass concentrations of 9%, 7%, 4%, and 1%, respectively, to finally obtain an osmium absorption liquid;
[0028] S3, sand core filtration: collect the osmium absorption liquid and let it settle for 3 hours, and finally filter it with a sand core funnel. The pore size of the sand core hole is 8 μm, and finally obtain pure osmium salt secondary distillation absorption liquid.
[0029] After testing, the primary osmium salt used in this embodiment contains 0.36% osmium, 2.51% sodium, 1.00% iron, and 0.17% arsenic. After being treated by the method of this embodiment, the osmium concentration in the obtained pure osmium salt secondary distillation absorption liquid is 9.05 g / L, and the content of impurities such as sodium, iron, and arsenic is less than 0.05 g / L.
[0030] Example 2
[0031] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0032] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:3.5 and add it to a distillation device, then slowly add 12% sulfuric acid by total volume, and stir to react for 20 minutes; then raise the temperature to 95°C and keep warm, and continuously add 3% peroxyacetic acid solution as an oxidant during the insulation process, and the addition rate of the peroxyacetic acid solution is controlled at 15L / h to perform acid oxidation distillation of osmium;
[0033] S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of absorption liquids with different concentrations for gradient absorption, wherein the 4 levels of absorption liquids with different concentrations are sodium formate solutions with mass concentrations of 11%, 9%, 6%, and 3%, respectively, to finally obtain an osmium absorption liquid;
[0034] S3, sand core filtration: collect the osmium absorption liquid and let it settle for 5 hours, and finally filter it with a sand core funnel. The pore size of the sand core hole is 13 μm, and finally obtain pure osmium salt secondary distillation absorption liquid.
[0035] After testing, the primary osmium salt used in this embodiment contains 0.41% osmium, 2.63% sodium, 1.06% iron, and 0.20 arsenic. After being treated by the method of this embodiment, the osmium concentration in the obtained pure osmium salt secondary distillation absorption liquid is 9.11 g / L, and the content of impurities such as sodium, iron, and arsenic is less than 0.04 g / L.
[0036] Example 3
[0037] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0038] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:3 and add it to the distillation device, then slowly add 10% sulfuric acid by total volume, and stir to react for 15 minutes; then raise the temperature to 92°C and keep warm, and continuously add 2.5% peroxyacetic acid solution as an oxidant during the insulation process, and the addition rate of the peroxyacetic acid solution is controlled at 12L / h to perform acid oxidation distillation of osmium;
[0039] S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of absorption liquids with different concentrations for gradient absorption, wherein the 4 levels of absorption liquids with different concentrations are sodium formate solutions with mass concentrations of 10%, 8%, 5%, and 2%, respectively, to finally obtain an osmium absorption liquid;
[0040] S3, sand core filtration: collect the osmium absorption liquid and let it settle for 4 hours, and finally filter it with a sand core funnel. The pore size of the sand core hole is 10 μm, and finally obtain pure osmium salt secondary distillation absorption liquid.
[0041] After testing, the primary osmium salt used in this embodiment contains 0.38% osmium, 2.62% sodium, 1.03% iron, and 0.19% arsenic. After being treated by the method of this embodiment, the osmium concentration in the obtained pure osmium salt secondary distillation absorption liquid is 9.13 g / L, and the content of impurities such as sodium, iron, and arsenic is less than 0.03 g / L.
[0042] Example 4
[0043] A method for purifying an osmium salt by secondary distillation comprises the following steps:
[0044] S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:3 and add it to a distillation device, then slowly add 10% sulfuric acid by total volume, and stir to react for 20 minutes; then raise the temperature to 90°C and keep warm, and continuously add 2% peroxyacetic acid solution as an oxidant during the insulation process, and the addition rate of the peroxyacetic acid solution is controlled at 14L / h to perform acid oxidation distillation of osmium;
[0045] S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of absorption liquids with different concentrations for gradient absorption, wherein the 4 levels of absorption liquids with different concentrations are sodium formate solutions with mass concentrations of 10%, 8%, 5%, and 2%, respectively, to finally obtain an osmium absorption liquid;
[0046] S3, sand core filtration: collect the osmium absorption liquid and let it settle for 5 hours, and finally filter it with a sand core funnel. The pore size of the sand core hole is 8 μm, and finally obtain pure osmium salt secondary distillation absorption liquid.
[0047] After testing, the primary osmium salt used in this embodiment contains 0.63% osmium, 0.67% potassium, 1.37% sodium, 2.08% iron, and 0.11% arsenic. After being treated by the method of this embodiment, the osmium concentration in the obtained pure osmium salt secondary distillation absorption liquid is 11.34 g / L, and the content of impurities such as sodium, iron, and arsenic is less than 0.05 g / L.
[0048] Comparative Example 1
[0049] The difference between this comparative example and Example 3 is that the slurry ratio of the primary osmium salt to pure water is 1:2, and other conditions remain unchanged.
[0050] After testing, the osmium concentration in the obtained osmium salt secondary distillation absorption liquid was 7.89 g / L, and the content of impurities such as sodium, iron, and arsenic was above 0.1 g / L.
[0051] Comparative Example 2
[0052] The difference between this comparative example and Example 3 is that 15% of the total volume of sulfuric acid is added, and other conditions remain unchanged.
[0053] After testing, the osmium concentration in the obtained osmium salt secondary distillation absorption liquid was 8.10 g / L, and the content of impurities such as sodium, iron, and arsenic was above 0.1 g / L.
[0054] Comparative Example 3
[0055] The difference between this comparative example and Example 3 is that only three-level gradient absorption is performed, and other conditions remain unchanged.
[0056] After testing, the osmium concentration in the obtained osmium salt secondary distillation absorption liquid was 8.36 g / L, and the content of impurities such as sodium, iron, and arsenic was above 0.09 g / L.
[0057] Comparative Example 4
[0058] The difference between this comparative example and Example 3 is that no sand core filtration is performed, and other conditions remain unchanged.
[0059] After testing, the osmium concentration in the obtained osmium salt secondary distillation absorption liquid was 8.45 g / L, and the content of impurities such as sodium, iron, and arsenic was above 0.1 g / L.
[0060] 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 purifying an osmium salt by secondary distillation, characterized in that: The following steps are involved: S1, acid oxidation distillation: slurry the primary osmium salt with pure water at a solid-liquid ratio of 1:(2.5-3.5) and add it to a distillation device, then slowly add 8-12% sulfuric acid by total volume, stir and react; then increase the temperature and keep warm, and continuously add peroxyacetic acid solution as an oxidant during the insulation process to perform acid oxidation distillation of osmium; S2, gradient absorption: while acid oxidation distillation is being performed, the steam generated by the distillation is sequentially passed into 4 levels of sodium formate solutions of different concentrations for gradient absorption to obtain an osmium absorption solution; S3, sand core filtration: collect the osmium absorption liquid and let it settle, and finally filter it using a sand core funnel to finally obtain pure osmium salt secondary distillation absorption liquid.
2. A method for purifying an osmium salt by secondary distillation according to claim 1, characterized in that: Step S1: the stirring reaction time is 10-20 min; and / or the insulation temperature is 90-95°C.
3. A method for purifying an osmium salt by secondary distillation according to claim 1, characterized in that: The precipitation time in step S3 is 3-5h.
4. A method for purifying a primary osmium salt by secondary distillation according to claim 1, characterized in that: The sand core hole diameter of the sand core hole in step S3 is 8-13 μm.
5. The method for purifying an osmium salt by secondary distillation according to any one of claims 1 to 4, characterized in that: The mass concentration of the peroxyacetic acid solution in step S1 is 2-3%, and the addition rate of the peroxyacetic acid solution is 10-15 L / h.
6. A method for purifying a primary osmium salt by secondary distillation according to claim 5, characterized in that: The mass concentrations of the four levels of sodium formate solutions of different concentrations in step S2 are 9-11%, 7-9%, 4-6% and 1-3% respectively.