Method for recovering uranium from amidoxime-based seawater uranium extraction material
Through steps such as acid solution washing and anion exchange resin enrichment, the problem of desorption and recovery of uranium from seawater uranium extracting materials is solved, and efficient and economical uranium recycling is achieved, which is suitable for the utilization of seawater uranium resources.
Patent Information
- Application Number
- CN202411937370.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-03-28
AI Technical Summary
The lack of effective methods in the prior art to desorb and recover uranium from uranium extracted materials after seawater, resulting in the failure of full utilization of uranium resources.
The uranium extracting material is washed with an acid solution, and the uranium is desorbed into the washing solution by controlling the inlet rate and the concentration of the acid solution. Subsequently, uranium is enriched using anion exchange resin, and a solid containing uranium is obtained by an extraction-row extraction-precipitation process.
It has achieved efficient desorption and recovery of uranium from uranium extracted uranium materials with geminixime-based seawater. The uranium recovery rate reaches more than 70%, the purity of uranium products is greater than 60%, and the solution and resin used can be reused, with high application prospects.
Smart Images
Figure CN119710315A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for recovering uranium from amidoxime-based seawater uranium extraction material. Background Art
[0002] The total amount of uranium in the ocean is huge, nearly a thousand times the proven uranium reserves on land. Therefore, it is very meaningful to study and realize the economical extraction of uranium from seawater.
[0003] At present, the research on uranium extraction from seawater mainly focuses on the development of adsorption materials, while there is little research on the recovery of uranium extraction materials after uranium extraction from seawater and the desorption and recovery of uranium from uranium extraction materials. Only by desorbing and recovering uranium from uranium extraction materials can the uranium be further utilized.
[0004] There are many kinds of uranium extraction materials after extracting uranium from seawater, and the methods of desorbing and recovering uranium from different uranium extraction materials are also different. Currently, the commonly used material for adsorbing uranium from seawater is amidoxime polyacrylonitrile fiber material. Therefore, how to desorb and recover uranium from amidoxime polyacrylonitrile seawater uranium extraction materials needs to be studied in depth. Summary of the invention
[0005] In view of this, an object of the present invention is to provide a method for recovering uranium from amidoxime-based seawater uranium extraction materials. The method can effectively desorb and recover uranium from amidoxime-based seawater uranium extraction materials.
[0006] The present invention adopts the following technical solutions to achieve the above-mentioned purpose.
[0007] The present invention provides a method for recovering uranium from amidoxime-based seawater uranium extraction material, comprising the following steps:
[0008] 1) Providing an amidoxime-based seawater uranium extraction material that adsorbs uranium in seawater;
[0009] 2) the amidoxime-based seawater uranium extraction material in step 1) is loaded into an empty resin column, and then a 0.1-2 mol / L acid solution is introduced into the resin column in a bottom-in-top-out manner for washing, the liquid inlet speed is controlled to be 0.5-1.5 BV / h, and the washing liquid is collected, and the washing liquid contains uranium element;
[0010] The acid solution is selected from one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution. This is conducive to desorption and recovery of uranium from amidoxime-based seawater uranium extraction materials. The amount of acid solution used is small. When three resin columns are used in series, the amount of acid solution used is 7 to 8 BV, and the desorption rate is high.
[0011] In step 1), the amidoxime-based seawater uranium extraction material is preferably an amidoxime polyacrylonitrile seawater uranium extraction material. The amidoxime polyacrylonitrile material in the present invention can be obtained by amidoximating commercially available polyacrylonitrile fiber and then alkalizing it. The content of uranium element in the amidoxime-based seawater uranium extraction material is 1 to 6 mg uranium element / g of amidoxime dry material before adsorption.
[0012] In the present invention, the amidoxime-based seawater uranium extraction material can be first washed with water to remove the mud and other impurities on the surface, and the water used can be deionized water or purified water. Ultrasonic, oscillating and other methods can be used for washing.
[0013] The acid solution in step 2) is referred to as the first acid solution, preferably a sulfuric acid solution. The molar concentration of the first acid solution is preferably 0.4 to 1.5 mol / L, more preferably 0.5 to 1.0 mol / L. The liquid inlet speed can be controlled to be 0.5 to 1.5 BV / h, preferably 0.8 to 1.2 BV / h, more preferably 0.9 to 1.0 BV / h.
[0014] When the uranium content in the washing solution is less than or equal to 3 mg / L, stop washing.
[0015] According to the method of the present invention, preferably, in step 1), the amidoxime-based seawater uranium extraction material is an amidoxime-polyacrylonitrile seawater uranium extraction material.
[0016] According to the method of the present invention, preferably, in step 2), the diameter-to-height ratio of the resin column is 1:8 to 1:30, preferably 1:10 to 1:15. The diameter-to-height ratio refers to the ratio of the diameter to the height.
[0017] According to the method of the present invention, preferably, in step 2), multiple resin columns loaded with amidoxime-based seawater uranium extraction materials are used in series.
[0018] In the present invention, the resin column is an empty glass tube, which can be a resin column used during column chromatography. A plurality of resin columns can be used in series, for example, more than two resin columns can be used in series, so that the desorption capacity per unit time can be increased. According to a specific embodiment of the present invention, three resin columns equipped with amidoxime-based seawater uranium extraction material are used in series.
[0019] According to the method of the present invention, preferably, in step 2), when the uranium content in the washing solution is less than or equal to 3 mg / L, washing is stopped. According to a specific embodiment of the present invention, when the uranium content in the washing solution is 2 mg / L, washing is stopped. This can maximize the desorption of uranium and save the amount of the first acid solution.
[0020] The method according to the present invention preferably further comprises the following steps:
[0021] 3) passing the washing liquid in step 2) into an anion exchange resin column in an upper-in-lower-out manner, so that the uranium element in the washing liquid is adsorbed on the anion exchange resin, thereby obtaining an anion exchange resin column enriched with uranium;
[0022] 4) eluting the uranium-enriched anion exchange resin column with 8-25 vol% of the second acid solution in an upper-in-lower-out manner, and collecting the uranium-containing acid eluent;
[0023] 5) extracting the uranium-containing acid washing liquid with an organic extractant and separating the liquids to obtain an extracted organic liquid containing uranium;
[0024] 6) back-extracting the uranium-containing organic extract with water or the first alkaline solution to obtain an aqueous extract containing uranium;
[0025] 7) Adding a second alkaline solution to the aqueous extract containing uranium, adjusting the pH value of the aqueous extract to 8-12, causing precipitation, solid-liquid separation, and drying the separated solid to obtain a uranium-containing solid. In this way, the uranium desorbed from the amidoxime-based seawater uranium extraction material can be further purified and recovered to obtain a uranium-containing solid, which is convenient for storage and subsequent reprocessing.
[0026] In step 3), the anion exchange resin column is a strong alkaline anion exchange resin column. The resin brand can be 201 type, Lanxess TP107, DuPont Amberlite TM One of IRN78OH. Preferably, it is a LANXESS TP107 strong basic anion exchange resin column. This step can enrich the uranium in the washing liquid.
[0027] The liquid inlet speed is controlled to be 0.5-1.5 BV / h, preferably 0.8-1.2 BV / h, and more preferably 1.0-1.1 BV / h.
[0028] In step 4), the second acid solution is selected from one of sulfuric acid solution, hydrochloric acid solution and nitric acid solution, preferably sulfuric acid solution or nitric acid solution. The volume concentration of the second acid solution is 10-20 vol%, preferably 10-15 vol%. In step 4), the liquid inlet speed is controlled to be 0.5-2 BV / h, preferably 0.5-1.5 BV / h. This step will elute the uranium enriched in the anion exchange resin to obtain a rich eluent (i.e., an acid eluent containing uranium). In the present invention, the uranium content in the uranium-containing acid eluent is 300-5000 mg / L, preferably 500-5000 mg / L, and more preferably 3000-5000 mg / L.
[0029] In step 5), the volume ratio of the organic extractant to the uranium-containing acid eluent is 1:20 to 50, preferably 1:30 to 50. In the extraction, the organic extractant can be reused, so the present invention divides the uranium-containing acid eluent into multiple portions, and when a single portion is extracted once, the volume ratio of the organic extractant to the uranium-containing acid eluent is 1:5 to 10.
[0030] The organic extractant is a mixture of an extractant and a diluent, and the extractant can be selected from one of P204, TBP and N235, preferably N235 or TBP. The diluent is selected from one of sulfonated kerosene, hydrogenated kerosene and dodecane, preferably sulfonated kerosene or hydrogenated kerosene. In the organic extractant, the volume concentration of the extractant is 5-15 vol%, preferably 8-10 vol%. In this step, the uranium element is enriched again in the organic phase. The uranium content in the uranium-containing organic extraction liquid is 30-50 g / L.
[0031] According to a specific embodiment of the present invention, an anion exchange resin column enriched with uranium is eluted with 8-25 vol% nitric acid solution (second acid solution) in an upper-in-lower-out liquid inlet manner, and an acid eluent containing uranium is collected; the acid eluent containing uranium is extracted with an organic extractant (a mixture of TBP and hydrogenated kerosene) and separated to obtain an extracted organic liquid containing uranium.
[0032] According to another specific embodiment of the present invention, an anion exchange resin column enriched with uranium is eluted with a sulfuric acid solution (second acid solution) of 8 to 25 vol% in an upper-in-lower-out manner, and an acid eluent containing uranium is collected; the acid eluent containing uranium is extracted with an organic extractant (a mixture of N235 and sulfonated kerosene) and separated to obtain an extracted organic liquid containing uranium.
[0033] In step 6), the first alkaline solution is an alkaline carbonate solution or an alkaline bicarbonate solution, preferably an alkaline carbonate solution, for example, a sodium carbonate solution or a potassium carbonate solution. The alkaline bicarbonate is sodium bicarbonate or potassium bicarbonate. The concentration of the first alkaline solution is 1 to 20 wt%, preferably 8 to 20 wt%. In this step, a uranium-rich aqueous phase is obtained.
[0034] The volume ratio of the uranium-containing extraction organic solution to the first alkaline solution or water is 5:1 to 1:5, preferably 3 to 2:1. The temperature during the back extraction can be 25 to 40° C. According to a specific embodiment of the present invention, in step 6), the uranium-containing extraction organic solution is back extracted with water at 35 to 40° C. to obtain an aqueous extract containing uranium.
[0035] In step 7), the second alkaline solution is sodium hydroxide solution, potassium hydroxide solution or ammonia water, preferably sodium hydroxide solution. The solute concentration of the second alkaline solution is 0.5-2 mol / L. The pH value of the aqueous phase extract is preferably adjusted to 9-10.
[0036] In the present invention, the amidoxime-based seawater uranium extraction material is washed with a first acid solution, uranium is desorbed into the washing liquid, and then the uranium is enriched to a higher concentration using an anion exchange resin column. Then, the primary uranium product (i.e., uranium-containing solid) is obtained by the extraction-strip extraction-precipitation process steps. The method is simple, low in cost, and the purity of the uranium product is high, greater than 50%, preferably greater than 60%, and the washing liquid, eluent, resin, extractant, etc. used in the process can be reused, which has a high application prospect. The recovery rate of uranium is more than 70%.
[0037] According to the method of the present invention, preferably:
[0038] In step 3), the anion exchange resin column is a strong alkaline anion exchange resin column; the liquid inlet rate is 0.5 to 1.5 BV / h;
[0039] In step 4), the volume concentration of the second acid solution is 10-15 vol%; the second acid solution is selected from one of a sulfuric acid solution, a hydrochloric acid solution and a nitric acid solution.
[0040] According to the method of the present invention, preferably, in step 5), the volume ratio of the organic extractant to the uranium-containing acid washing solution is 1 to 1.5:1; the organic extractant is a mixture of an extractant and a diluent, the extractant is selected from one of P204, TBP and N235, and the diluent is selected from one of sulfonated kerosene, hydrogenated kerosene and dodecane; in the organic extractant, the volume concentration of the extractant is 5 to 15 vol%.
[0041] In the present invention, P204 is di(2-ethylhexyl) phosphate, TBP is tributyl phosphate, and N235 is trioctyldecyl tertiary amine.
[0042] According to the method of the present invention, preferably, in step 6), the first alkaline solution is an alkaline carbonate solution or an alkaline bicarbonate solution, and its mass concentration is 1 to 20 wt%.
[0043] According to the method of the present invention, preferably, in step 7), the second alkaline solution is sodium hydroxide solution, potassium hydroxide solution or ammonia water, and the solute concentration of the second alkaline solution is 0.5-2 mol / L.
[0044] The method of the present invention can effectively desorb and recover uranium from amidoxime-based seawater uranium extraction materials. According to the preferred technical scheme of the present invention, uranium can be effectively desorbed and recovered by controlling the liquid feeding method, liquid feeding speed and the concentration of the acid solution. Furthermore, the method of the present invention can recover uranium-containing solids by enriching, extracting, stripping and precipitating the washing liquid. The uranium content in the uranium-containing solid can reach more than 60%, and the uranium recovery rate is more than 70%, and can reach 80%. In addition, the method of the present invention is relatively simple to operate, and the acid solution, resin, extractant, etc. used can be reused, and has a high application prospect. BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Figure 1 The curve showing the change of uranium content with the volume of the washing liquid in step 2) of Example 1. DETAILED DESCRIPTION
[0046] BV refers to the bed volume in separation and purification, that is, the volume of uranium extraction material loaded in the resin column.
[0047] The recovery rate of uranium element = M1 / M0×100%, wherein M0 is the mass of uranium in the amidoxime polyacrylonitrile seawater uranium extraction material that adsorbs uranium in seawater, and M1 is the mass of uranium in the uranium-containing solid.
[0048] The following are the raw materials used in the examples:
[0049] N235 extractant is trioctyldecyl tertiary amine, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. TBP is tributyl phosphate, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Amidoxime polyacrylonitrile seawater uranium extraction material was provided by Beijing Chemical Metallurgy Research Institute of Nuclear Industry.
[0050] Example 1
[0051] A amidoxime polyacrylonitrile seawater uranium extraction material (i.e., amidoxime-based seawater uranium extraction material) that absorbs uranium in seawater is provided, and the uranium extraction material is washed with deionized water to remove mud and other impurities on its surface. The uranium content in the uranium extraction material is 2.5-3.5 mg / g (based on the amidoxime polyacrylonitrile fiber dry material before adsorption), and the uranium extraction material is a fiber material.
[0052] The cleaned amidoxime-based seawater uranium extraction material as described above is loaded into an empty resin column, and three resin columns loaded with amidoxime-based seawater uranium extraction material are connected in series, and then 0.5 mol / L sulfuric acid solution (i.e., the first acid solution) is introduced into the resin column in a bottom-in-top-out manner for washing, and the liquid inlet speed is controlled to be 1BV / h, and the washing liquid is collected, and the washing liquid contains uranium element. Wherein, when the content of uranium element in the washing liquid is less than 3 mg / L (for example, 2 mg / L), the washing is stopped. Wherein, the diameter-to-height ratio (ratio of diameter to height) of each resin column is 1:12. Each resin column is loaded with 5000g of uranium extraction material. Wherein, the curve of the change of uranium content with the volume of the first acid solution is shown in FIG. Figure 1 .from Figure 1 It can be seen that when the uranium content in the scrubbing solution is 2 mg / L, the volume of the first acid solution used is 7 BV.
[0053] The washing liquid as described above is introduced into the LANXESS TP107 strong basic anion exchange resin column in an upper inlet and lower outlet manner, and the liquid inlet speed is controlled to be 1 BV / h, so that the uranium element in the washing liquid is adsorbed on the anion exchange resin to obtain an anion exchange resin column enriched with uranium.
[0054] The uranium-enriched anion exchange resin column was eluted with a 10 vol% sulfuric acid solution (i.e., the second acid solution) in an upper-in-lower-out manner, the liquid inlet speed was controlled to be 0.5 BV / h, and the uranium-containing sulfuric acid eluent was collected; the concentration of uranium element in the collected uranium-containing sulfuric acid eluent was 5000 mg / L.
[0055] The sulfuric acid eluent containing uranium element is extracted with an organic extractant and separated to obtain an extracted organic liquid containing uranium. The volume ratio of the organic extractant to the sulfuric acid eluent containing uranium element is 1:30 (the organic extractant is reused, the sulfuric acid eluent containing uranium element is divided into multiple portions, and when a single portion is extracted once, the volume ratio of the organic extractant to the sulfuric acid eluent containing uranium element is 1:5). The organic extractant is a mixture of extractant N235 and sulfonated kerosene, wherein the volume concentration of the extractant N235 is 10 vol%.
[0056] The uranium-containing organic extract is back-extracted with a 10% sodium carbonate solution (i.e., the first alkaline solution) to obtain an aqueous extract containing uranium, wherein the volume ratio of the 10% sodium carbonate solution to the uranium-containing organic extract is 1:2.
[0057] Under stirring, 1 mol / L sodium hydroxide solution (i.e., the second alkaline solution) is added dropwise to the aqueous extract containing uranium, and the pH value of the aqueous extract is adjusted to 9. A precipitate is precipitated, and the precipitate is allowed to stand, and then the solid-liquid separation is performed. The separated solid is dried to obtain the uranium-containing solid.
[0058] The content of uranium element (U) in the uranium-containing solid was 52.24 wt %, and the recovery rate of uranium element was 70 %.
[0059] Example 2
[0060] A amidoxime polyacrylonitrile seawater uranium extraction material (i.e., amidoxime-based seawater uranium extraction material) that adsorbs uranium in seawater is provided, and the uranium extraction material is washed with deionized water to remove mud and other impurities on its surface. The uranium content in the uranium extraction material is 2.5 to 3.5 mg / g (non-uniform adsorption) (based on the amidoxime polyacrylonitrile fiber dry material before adsorption), and the uranium extraction material is a fiber material.
[0061] The amidoxime-based seawater uranium extraction material as described above after cleaning is loaded into an empty resin column, and three resin columns equipped with amidoxime-based seawater uranium extraction material are connected in series, and then 0.5mol / L sulfuric acid solution (i.e., the first acid solution) is passed into the resin column in a bottom-in-top-out liquid inlet mode for washing, and the liquid inlet speed is controlled to be 1BV / h, and washing liquid is collected, and the washing liquid contains uranium element. Wherein, when the content of uranium element in the washing liquid is less than 3mg / L (for example, 2mg / L), washing is stopped. Wherein, the diameter-to-height ratio (ratio of diameter to height) of each resin column is 1:12. Each resin column is respectively loaded with 5000g of uranium extraction material.
[0062] The washing liquid as described above is introduced into the LANXESS TP107 strong basic anion exchange resin column in an upper inlet and lower outlet manner, and the liquid inlet speed is controlled to be 1 BV / h, so that the uranium element in the washing liquid is adsorbed on the anion exchange resin to obtain an anion exchange resin column enriched with uranium.
[0063] The uranium-enriched anion exchange resin column was eluted with a 10 vol% nitric acid solution (i.e., the second acid solution) in an upper-in-lower-out manner, the inlet speed was controlled to be 0.5 BV / h, and the uranium-containing nitric acid eluent was collected; the concentration of uranium element in the collected uranium-containing nitric acid eluent was 3000 mg / L.
[0064] The nitric acid eluent containing uranium element is extracted with an organic extractant and separated to obtain an extracted organic liquid containing uranium. The volume ratio of the organic extractant to the nitric acid eluent containing uranium element is 1:50 (the extractant is reused, the nitric acid eluent containing uranium element is divided into multiple portions, and when a single portion is extracted once, the volume ratio of the organic extractant to the nitric acid eluent containing uranium element is 1:5). The organic extractant is a mixture of extractant TBP and hydrogenated kerosene, wherein the volume concentration of the extractant TBP is 5 vol%.
[0065] The uranium-containing organic extract is back-extracted with deionized water at 40° C. to obtain an aqueous extract containing uranium, wherein the volume ratio of deionized water to the uranium-containing organic extract is 1:2.
[0066] Under stirring, 1 mol / L sodium hydroxide solution (i.e., the second alkaline solution) is added dropwise to the aqueous extract containing uranium, and the pH value of the aqueous extract is adjusted to 9. A precipitate is precipitated, and the precipitate is allowed to stand, and then the solid-liquid separation is performed. The separated solid is dried to obtain the uranium-containing solid.
[0067] The content of uranium element (U) in the uranium-containing solid was 64.82 wt %, and the recovery rate of uranium element was 80 %.
[0068] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.
Claims
1. A method for recovering uranium from amidoxime-based seawater uranium extraction material, characterized in that: The following steps are involved: 1) Providing an amidoxime-based seawater uranium extraction material that adsorbs uranium in seawater; 2) the amidoxime-based seawater uranium extraction material in step 1) is loaded into an empty resin column, and then a 0.1-2 mol / L acid solution is introduced into the resin column in a bottom-in-top-out manner for washing, and the liquid inlet speed is controlled to be 0.5-1.5 BV / h, and the washing liquid is collected, and the washing liquid contains uranium element; Wherein, the acid solution is selected from one of hydrochloric acid solution, sulfuric acid solution and nitric acid solution.
2. The method according to claim 1, characterized in that In step 1), the amidoxime-based seawater uranium extraction material is an amidoxime-polyacrylonitrile seawater uranium extraction material.
3. The method according to claim 1, characterized in that In step 2), the diameter-to-height ratio of the resin column is 1:8 to 1:
30.
4. The method according to claim 1, characterized in that: In step 2), multiple resin columns loaded with amidoxime-based seawater uranium extraction materials are used in series.
5. The method according to claim 1, characterized in that: In step 2), when the uranium content in the washing solution is less than or equal to 3 mg / L, washing is stopped.
6. The method according to any one of claims 1 to 5, characterized in that: The following steps are also included: 3) passing the washing liquid in step 2) into an anion exchange resin column in an upper-in-lower-out manner, so that the uranium element in the washing liquid is adsorbed on the anion exchange resin, thereby obtaining an anion exchange resin column enriched with uranium; 4) eluting the uranium-enriched anion exchange resin column with 8-25 vol% of the second acid solution in an upper-in-lower-out manner, and collecting the uranium-containing acid eluent; 5) extracting the uranium-containing acid washing liquid with an organic extractant and separating the liquids to obtain an extracted organic liquid containing uranium; 6) back-extracting the uranium-containing organic extract with water or the first alkaline solution to obtain an aqueous extract containing uranium; 7) Adding a second alkaline solution to the aqueous extract containing uranium, adjusting the pH value of the aqueous extract to 8-12, causing precipitation, solid-liquid separation, and drying the separated solid to obtain a uranium-containing solid.
7. The method according to claim 6, characterized in that: In step 3), the anion exchange resin column is a strong alkaline anion exchange resin column; the liquid inlet rate is 0.5 to 1.5 BV / h; In step 4), the volume concentration of the second acid solution is 10-20 vol%; the second acid solution is selected from one of a sulfuric acid solution, a hydrochloric acid solution and a nitric acid solution.
8. The method according to claim 6, characterized in that In step 5), the volume ratio of the organic extractant to the uranium-containing acid washing solution is 1 to 1.5:1; wherein the organic extractant is a mixture of an extractant and a diluent, the extractant is selected from one of P204, TBP and N235, and the diluent is selected from one of sulfonated kerosene, hydrogenated kerosene and dodecane; in the organic extractant, the volume concentration of the extractant is 5 to 15 vol%.
9. The method according to claim 6, characterized in that In step 6), the first alkaline solution is an alkaline carbonate solution or an alkaline bicarbonate solution, and its mass concentration is 1-20 wt%.
10. The method according to claim 6, characterized in that In step 7), the second alkaline solution is sodium hydroxide solution, potassium hydroxide solution or ammonia water, and the solute concentration of the second alkaline solution is 0.5-2 mol / L.