Preparation method of solid phase adsorption resin and application thereof in uranium purification
The prepared solid-phase adsorption resin effectively removes trace amounts of plutonium in the uranium purification cycle, solving the problem of excessive plutonium content in uranium products in existing technologies and achieving efficient and convenient uranium purification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA INSTITUTE OF ATOMIC ENERGY
- Filing Date
- 2023-12-18
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies are insufficient to effectively remove trace amounts of plutonium in uranium purification cycles, resulting in excessive plutonium content in uranium products. Furthermore, existing methods are cumbersome to operate, produce large volumes of waste liquid, or require acidity adjustments, making them unsuitable for the deep purification of large quantities of uranium products.
A polyamide ligand was prepared by reacting triethylamine, carbodiimide hydrochloride, and 1-hydroxyphenyltriazole with dialkylamine in dichloromethane using triacetic acid as a catalyst. The ligand was then loaded onto a P120 support to form a solid-phase adsorption resin for the purification of trace amounts of plutonium in uranium feed liquid.
It achieves deep purification of trace amounts of plutonium in large quantities of uranium within a wide acidity range, with short adsorption time, high purification depth, simple operation, no loss of uranium products, and wide applicability to a wide range of uranium and plutonium concentrations.
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Figure CN117696013B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of spent fuel reprocessing technology, specifically relating to a method for preparing a solid-phase adsorption resin and its application in the uranium purification cycle of the reprocessing process. Background Technology
[0002] Uranium purification cycle, as one of the three main cycles in the reprocessing procedure, is a key research area in the reprocessing process. To reduce the volume of radioactive waste, this cycle typically employs a concentration process. First, the 1CU feed liquid from the co-decontamination-separation cycle is evaporated and concentrated. Then, the concentrated feed liquid undergoes extraction-washing-back-extraction to separate trace amounts of plutonium from uranium, ultimately yielding qualified uranium products. However, the uranium-to-plutonium mass ratio in the uranium purification cycle is very high, typically exceeding 10:1. 6 In this situation, trace amounts of plutonium in the system are extremely difficult to remove, leading to excessive plutonium levels in the 2EU product solution. Currently, there is no suitable method in China for the deep purification of trace plutonium in large quantities of uranium products under these conditions.
[0003] Currently, the main methods for removing trace amounts of plutonium from large quantities of uranium during spent fuel reprocessing are solvent extraction, ion exchange, and solid-phase adsorption.
[0004] (1) Solvent extraction method: Plutonium is generally extracted using 2-thiophenecarboxylic acid trifluoroacetone (TTA) as the extractant and xylene as the diluent in a 1-2 mol / L nitric acid environment. However, this method requires adjustment of the acidity of the feed solution, and the extraction kinetics of TTA for plutonium are slow and the extraction time is long. The solvent xylene used has adverse effects on the environment, so it is not suitable for the deep purification of large amounts of feed solution.
[0005] (2) Ion exchange method: The basic principle of the ion exchange method is to adjust the chemical valence of plutonium to tetravalent, thereby forming a plutonium nitrate complex anion in a high acid system, which is then adsorbed on anion exchange chromatography. However, this method also requires acid adjustment, is cumbersome to operate, generates a large amount of waste liquid, and is not suitable for the deep purification of uranium products.
[0006] (3) Solid phase adsorption method: This method uses solid phase adsorption materials to selectively adsorb plutonium in the feed solution. However, the applicable uranium and plutonium concentration range is narrow, the selectivity is poor, and some materials still require acidity adjustment to achieve plutonium adsorption. Summary of the Invention
[0007] The purpose of this invention is to address the shortcomings of current deep purification technologies for trace amounts of plutonium in large quantities of uranium by providing a method for preparing a solid-phase adsorption resin and its application in uranium purification. This resin has a wide range of applicable acidities, is easy to operate, and does not cause loss of uranium in the uranium feed solution, thus showing great application potential.
[0008] To achieve the above objectives, the technical solution of the present invention is as follows:
[0009] A method for preparing a solid-phase adsorption resin includes the following steps:
[0010] (1) Using triethylamine, carbodiimide hydrochloride and 1-hydroxyphenyltriazole as catalysts, a substitution reaction was carried out between nitrotriacetic acid and dialkylamine in dichloromethane solvent. The reaction product was dried and impurities were removed by vacuum distillation to obtain the polyamide ligand product.
[0011] (2) The polyamide ligands obtained in step (1) are loaded onto the P120 support by vacuum impregnation to obtain solid-phase adsorption resin.
[0012] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (1), the alkyl group in the dialkylamine is a C1-C8 alkyl group.
[0013] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (1), the reaction product is washed sequentially with NaOH solution, HCl solution and saturated NaCl solution, dried with anhydrous sodium sulfate and then distilled under reduced pressure to remove impurities to obtain the polyamide ligand product.
[0014] Furthermore, the reaction products were washed twice, sequentially with 1M NaOH solution, 1M HCl solution, and saturated NaCl solution.
[0015] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (1), the reaction is carried out at room temperature.
[0016] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (1), the molar ratio of nitrotriacetic acid to dialkylamine is 1:3; the molar amounts of triethylamine, carbodiimide hydrochloride and 1-hydroxyphenyltriazole are 5-20% of the molar amount of nitrotriacetic acid.
[0017] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (2), the polyamide ligand is dissolved in dichloromethane solvent, mixed with an appropriate amount of P120 carrier and stirred thoroughly. After stirring, the organic solvent is removed by rotary evaporator, and then the solid is placed in a vacuum drying oven to dry thoroughly to obtain the solid-phase adsorption resin.
[0018] Furthermore, the rotary evaporator has a negative pressure of 20–100 mPa, a rotation speed of 40–150 r / min, and the temperature is raised from room temperature to 35–40°C, and then the rotary evaporation continues for 30–60 min until the mixture becomes a loose powdery solid.
[0019] Furthermore, the product is dried in the vacuum drying oven at 55–60°C for 12–15 hours under a negative pressure of 0.1–0.12 kPa.
[0020] Furthermore, in the preparation method of the solid-phase adsorption resin as described above, in step (2), the polyamide ligand loading in the obtained solid-phase adsorption resin is 10-50 wt.%.
[0021] Furthermore, the solid-phase adsorption resin prepared by the above method will be used for the purification of trace amounts of plutonium in uranium-containing liquid.
[0022] The uranium-containing liquid contains uranium at a concentration of 30–120 g / L and plutonium at a concentration of 10 g / L. -6 ~10 -3 g / L, nitric acid concentration is 0.01~0.5mol / L.
[0023] The purification method involves placing an appropriate amount of solid-phase adsorption resin into a uranium-containing liquid, shaking it thoroughly to remove the solid-phase adsorption resin, and then measuring the concentrations of uranium and plutonium in the liquid.
[0024] Furthermore, the adsorbed solid-phase adsorption resin was eluted with a 0.01–0.5 mol / L nitric acid solution to recover a small amount of uranium from the resin.
[0025] The beneficial effects of this invention are as follows:
[0026] 1) The solid-phase adsorption resin prepared by the method of this invention can achieve deep purification of trace amounts of plutonium in large quantities of uranium over a wide range. Static adsorption test results show that for simulated solutions meeting the concentration requirements, the adsorption time reaches equilibrium within 3 minutes, at which point the plutonium concentration in the clear liquid after adsorption is below 10. -7 The concentration is g / L, indicating a very high purification depth. Small amounts of uranium adhering to the adsorption resin can be easily eluted with a 0.01–0.5 mol / L nitric acid solution without causing uranium loss.
[0027] 2) The process of purifying uranium using this solid-phase adsorption resin is simple and convenient, requiring no pretreatment of the raw materials before purification, and has excellent application prospects. This solid-phase adsorption resin is suitable for the deep purification of trace amounts of plutonium in large quantities of uranium, and has a wide applicable concentration range of uranium, plutonium, and acids. It achieves high purification depth, is easy to operate, and is superior to existing separation materials in related fields. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the solid-phase adsorption resin synthesis method of the present invention. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0030] like Figure 1 As shown, the method for preparing solid-phase adsorption resin provided by the present invention consists of two parts: the synthesis of polyamide ligands and the synthesis of solid-phase adsorption resin.
[0031] (1) Synthesis of polyamide ligands
[0032] Using triethylamine, carbodiimide hydrochloride (EDCI), and 1-hydroxyphenyltriazole (HOBT) as catalysts, a substitution reaction was carried out between nitric acid triacetic acid and dialkylamines (C1-C8 alkyl) in dichloromethane solvent at room temperature. The product was then dried and impurities were removed by vacuum distillation to obtain the corresponding polyamide ligand product.
[0033] (2) Synthesis of solid-phase adsorption resins
[0034] Polyamide ligands were loaded onto a P120 support (a common porous support based on polystyrene and divinylphenyl copolymer or polymethacrylate, an existing material) using a vacuum impregnation method. The polyamide ligands were dissolved in dichloromethane solvent and transferred to a single-necked flask containing a certain amount of P120 support, then stirred thoroughly. After stirring, the organic solvent was removed using a rotary evaporator. The rotary evaporator was operated at a negative pressure of 20–100 mPa, a rotation speed of 40–150 r / min, and the temperature was raised from room temperature to 35–40°C, followed by further rotary evaporation for 30–60 min until the mixture in the flask became a loose powdery solid. Subsequently, the solid was placed in a vacuum drying oven for 12–15 hours at a temperature of 55–60°C and a negative pressure of 0.1–0.12 kPa. After thorough vacuum drying, the solid-phase adsorption resin described in this invention was obtained. The polyamide ligand loading was 10–50 wt.%.
[0035] The solid-phase adsorption resin prepared by the above method is used for the deep purification of trace plutonium in uranium-containing liquid. The specific method is as follows:
[0036] 1. Prepare a simulated feed solution with a uranium concentration of 30–120 g / L and a plutonium concentration of 10 g / L. -6 ~10 -3 g / L, nitric acid concentration of 0.01~0.5mol / L.
[0037] 2. Add 0.2–2.0 g of solid-phase adsorption resin to 10 mL of simulated feed solution, shake and adsorb for 5 min. After adsorption is complete, centrifuge and take the supernatant for analysis of uranium and plutonium concentrations.
[0038] 3. Using 0.01–0.5 mol / L HNO3 as the eluent, add it to the adsorption resin after adsorption in step 2, shake and elute for 2 min, centrifuge and take the supernatant to analyze the uranium and plutonium concentrations.
[0039] Actual deep purification results: For all the prepared simulated solutions of various concentrations, the plutonium content was less than 10 after purification by solid-phase adsorption resin. -7 g / L.
[0040] Example 1
[0041] Preparation method of solid phase adsorption resin:
[0042] (1) Synthesis of polyamide ligands
[0043] Nitroglycerotriacetic acid (95.6 g, 0.5 mol), dialkylamines (C1–C8) (C2 as an example: 154.5 mL, 1.5 mol), and a small amount of triethylamine (14 mL, 0.1 mol) were dissolved in dichloromethane (150 mL) in the specified reaction ratio. After dissolution by stirring at room temperature, carbodiimide hydrochloride (EDCI) (19 g, 0.1 mol) and 1-hydroxyphenyltriazole (HOBT) (13.5 g, 0.1 mol) were added in proportion. The mixture was stirred at room temperature for 24 hours to allow for complete reaction. Subsequently, the product was washed twice successively with 1 M NaOH solution, 1 M HCl solution, and saturated NaCl solution. After drying with anhydrous sodium sulfate, impurities were removed by vacuum distillation to obtain the corresponding polyamide ligand product.
[0044] The amounts of triethylamine, carbodiimide hydrochloride, and 1-hydroxyphenyltriazole in the above reactants can be adjusted appropriately, generally ranging from 5% to 20% of the total amount of triacetic acid.
[0045] (2) Synthesis of solid-phase adsorption resins
[0046] 5g of polyamide ligand was dissolved in dichloromethane and transferred to a single-necked flask containing 10g of P120 support. The mixture was stirred thoroughly for 1 hour. After stirring, the organic solvent was removed using a rotary evaporator. The negative pressure was 60 mPa, the rotation speed was 80 r / min, and the temperature was increased from 20°C to 35°C. Evaporation continued at 35°C for 60 minutes until the mixture in the flask became a loose powdery solid. The solid was then placed in a vacuum drying oven at 55°C and a negative pressure of 0.1 kPa for 12 hours. After thorough vacuum drying, the solid-phase adsorption resin described in this invention was obtained.
[0047] The following are several examples of using solid-phase adsorption resins to simulate the deep purification of trace plutonium in uranium-containing liquids.
[0048] Example 2
[0049] The solution contains 10 mL of simulated feed solution (with a uranium concentration of 70 g / L and a plutonium concentration of 2*10). -5 Add 0.5 g of the solid-phase adsorption resin described in this invention to a centrifuge tube containing uranium (uranium concentration 10 g / L, nitric acid concentration 0.2 mol / L), and shake thoroughly for 5 min to allow adsorption. After adsorption is complete, the concentration of uranium in the supernatant is measured to be 69.3 g / L and the concentration of plutonium is 6.2 × 10⁻⁶ g / L. -8 g / L. After washing the adsorbed resin with 5 mL of 0.2 mol / L nitric acid solution for 2 min by shaking, the uranium concentration in the supernatant was measured to be 1.29 g / L, with a uranium balance of 99.92%. This method achieves deep purification of trace amounts of plutonium in large quantities of uranium while ensuring almost no loss of uranium products.
[0050] Example 3
[0051] A 10 mL sample solution (containing 100 g / L uranium and 3.4 x 10⁻⁶ plutonium) was prepared. -4 0.7 g of the solid-phase adsorption resin described in this invention was added to a centrifuge tube containing uranium (uranium concentration 1 g / L, nitric acid concentration 0.1 mol / L) and the mixture was shaken thoroughly for 5 min to allow adsorption. After adsorption was complete, the concentration of uranium in the supernatant was measured to be 98.9 g / L and the concentration of plutonium was 8.7 × 10⁻⁶ g / L. -8 g / L. After washing the adsorbed resin with 5 mL of 0.1 mol / L nitric acid solution for 2 min by shaking, the uranium concentration in the supernatant was measured to be 2.08 g / L, with a uranium balance of 99.94%. This method achieves deep purification of trace amounts of plutonium in large quantities of uranium while ensuring almost no loss of uranium products.
[0052] Example 4
[0053] A 10 mL sample solution (containing 40 g / L uranium and 3.1 x 10⁻⁶ plutonium) was prepared. -6 Add 0.5g of the solid-phase adsorption resin described in this invention to a centrifuge tube containing uranium (uranium concentration 1.5 g / L, nitric acid concentration 0.5 mol / L), and shake thoroughly for 5 minutes for adsorption. After adsorption is complete, the concentration of uranium in the supernatant is measured to be 39.8 g / L and the concentration of plutonium is 3.9 × 10⁻⁶ g / L. -8 g / L. After washing the adsorbed resin with 5 mL of 0.5 mol / L nitric acid solution for 2 min by shaking, the uranium concentration in the supernatant was measured to be 0.39 g / L, and the uranium balance result was 99.99%. This method achieves deep purification of trace amounts of plutonium in large quantities of uranium while ensuring almost no loss of uranium products.
[0054] Example 5
[0055] A 10 mL sample solution (containing 64 g / L uranium and 3.7 x 10⁻⁶ plutonium) was prepared. -6Add 0.5 g of the solid-phase adsorption resin described in this invention to a centrifuge tube containing uranium (uranium concentration 1.5 g / L, nitric acid concentration 0.01 mol / L), and shake thoroughly for 5 min to allow adsorption. After adsorption is complete, the concentration of uranium in the supernatant is measured to be 63.4 g / L and the concentration of plutonium is 4.3 × 10⁻⁶ g / L. -8 g / L. After washing the adsorbed resin with 5 mL of 0.1 mol / L nitric acid solution for 2 min by shaking, the uranium concentration in the supernatant was measured to be 1.13 g / L, with a uranium balance of 99.95%. This method achieves deep purification of trace amounts of plutonium in large quantities of uranium while ensuring almost no loss of uranium products.
[0056] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. Thus, the invention also intends to include such variations and adaptations if they fall within the scope of the claims and their equivalents.
[0057] The above embodiments are merely illustrative examples of the present invention. The present invention may also be implemented in other specific ways or forms without departing from its spirit or essential characteristics. Therefore, the described embodiments should be considered illustrative rather than limiting in any respect. The scope of protection of the present invention should be defined by the claims, and any variations equivalent to the intent and scope of the claims should also be included within the scope of the present invention.
Claims
1. A method for uranium purification using a solid-phase adsorption resin, characterized in that, The solid-phase adsorption resin is prepared by the following method: (1) Using triethylamine, carbodiimide hydrochloride and 1-hydroxyphenyltriazole as catalysts, a substitution reaction is carried out between nitric acid triacetic acid and dialkylamine in dichloromethane solvent. The reaction product is dried and impurities are removed by vacuum distillation to obtain a polyamide ligand product; the alkyl group in the dialkylamine is C1-C8 alkyl; the molar ratio of nitric acid triacetic acid to dialkylamine is 1:3; the molar amounts of triethylamine, carbodiimide hydrochloride and 1-hydroxyphenyltriazole are 5-20% of the molar amount of nitric acid triacetic acid; (2) The polyamide ligands obtained in step (1) are loaded onto the P120 support by vacuum impregnation to obtain a solid-phase adsorption resin; the P120 support is a porous support based on polystyrene-divinylphenyl copolymer or polymethacrylate. The solid-phase adsorption resin is used to adsorb trace amounts of plutonium in a uranium-containing liquid, wherein the uranium concentration in the liquid is 30–120 g / L and the plutonium concentration is 10 g / L. -6 ~3.4×10 -4 g / L, nitric acid concentration is 0.01~0.5mol / L.
2. The method as described in claim 1, characterized in that, In step (1), the reaction product is washed sequentially with NaOH solution, HCl solution and saturated NaCl solution, dried with anhydrous sodium sulfate and then distilled under reduced pressure to remove impurities to obtain the polyamide ligand product.
3. The method as described in claim 2, characterized in that, The reaction products were washed twice, sequentially with 1M NaOH solution, 1M HCl solution, and saturated NaCl solution.
4. The method as described in claim 1, characterized in that, In step (1), the reaction is carried out at room temperature.
5. The method as described in claim 1, characterized in that, In step (2), the polyamide ligand is dissolved in dichloromethane solvent, mixed with an appropriate amount of P120 carrier and stirred thoroughly. After stirring, the organic solvent is removed by rotary evaporator, and then the solid is placed in a vacuum drying oven to dry thoroughly to obtain the solid phase adsorption resin.
6. The method as described in claim 5, characterized in that, The rotary evaporator has a negative pressure of 20–100 mPa, a rotation speed of 40–150 r / min, and the temperature is raised from room temperature to 35–40°C. Then, the rotary evaporator is continued for 30–60 min until the mixture becomes a loose powdery solid.
7. The method as described in claim 5, characterized in that, Dry in the vacuum drying oven at 55-60°C for 12-15 hours under a negative pressure of 0.1-0.12 kPa.
8. The method as described in claim 1, characterized in that, In step (2), the polyamide ligand loading in the solid-phase adsorption resin is 10-50 wt.%.
9. The method as described in claim 1, characterized in that, Add an appropriate amount of solid-phase adsorption resin to the uranium-containing liquid, shake thoroughly to adsorb, remove the solid-phase adsorption resin, and measure the concentration of uranium and plutonium in the liquid.
10. The method as described in claim 1, characterized in that, The adsorbed solid-phase adsorption resin was eluted with 0.01–0.5 mol / L nitric acid solution to recover a small amount of uranium from the resin.