Chelating solid phase extraction packing material, its preparation and use

Abstract

The application discloses a preparation method and application of a novel chelating solid-phase extraction filler which can be used for separation of uranium and rare earth elements in a strong acid solution. The chelating solid-phase extraction filler is prepared by covalently bonding a kind of phenanthroline derivative chelating ligand to the surface of polystyrene polymer microspheres. The filler has a good separation effect on uranium and rare earth elements in a strong acid solution, has a strong adsorption selectivity on uranium, and is especially suitable for extraction recovery of uranium in strong acid spent fuel digestion liquid and efficient separation of uranium and fission product lanthanide series elements. The solid-phase extraction method based on the novel chelating ion solid-phase extraction filler has the advantages of rapid separation, good selectivity, excellent adsorption effect on uranium in a strong acid environment and the like, and has good application potential in the fields of efficient treatment of spent fuel and burnup analysis.

Description

TECHNICAL FIELD

[0001] The present application relates to a new type of solid phase extraction filler and a preparation method thereof, in particular to a new type of chelating solid phase extraction filler with a chelating ligand as a bonded phase. BACKGROUND

[0002] High efficient separation of uranium and lanthanide series elements has important application value in nuclear industry and rare earth metallurgy. For example, in spent fuel recycling, uranium and fission product rare earth elements in spent fuel are completely separated to realize the recycling of uranium, and in the process of separation and purification of rare earth metallurgy, trace amounts of uranium and thorium contained in rare earth elements are removed. At present, the most commonly used separation method in the field of rare earth metallurgy and spent fuel recycling in nuclear industry is liquid-liquid extraction technology. Although the production cost of liquid-liquid extraction technology is low and it is suitable for large-scale production, its separation efficiency is low and the purity of the product is generally not high. Moreover, in the application of radioactive material separation, there are some defects that cannot be ignored, such as the use of a large amount of toxic volatile organic solvents in the separation process, hydrolysis and radiation degradation of extractants and solvents, formation of the third phase in the extraction process, and generation of a large amount of secondary radioactive waste.

[0003] In order to solve the defects of liquid-liquid extraction technology, researchers have developed solid phase extraction based on extraction resin. Although the extraction resin separation technology greatly improves the problems of slow mass transfer rate and low separation efficiency of liquid-liquid extraction method, the stability of the prepared solid phase extraction material is poor due to the physical coating or impregnation method of the extractant on the solid substrate, thereby causing the short service life of the material. On the other hand, since the extraction resin technology is essentially a liquid-liquid extraction technology, the mass transfer rate and stability of the extraction resin are still far behind the solid phase extraction filler prepared by covalent bonding method.

[0004] Therefore, in view of the problems existing in the separation and purification method of uranium and lanthanide series elements, it is of great significance to develop a new type of solid phase extraction filler with high efficiency, stability and low cost for the recycling of uranium and the removal of trace amounts of uranium in rare earth samples. In the present application, we plan to prepare a kind of covalent bonded solid phase extraction filler based on o-phenanthroline chelating ligand. By relying on the strong affinity of o-phenanthroline chelating ligand to actinide elements, we try to use the filler to separate uranium and rare earth elements in different acidic solutions, and provide a new idea for the development of solid phase extraction materials suitable for the separation of uranium and rare earth elements in strong acid solution. SUMMARY

[0005] The purpose of the present application is to provide a new type of solid phase extraction filler and a preparation method thereof. The solid phase extraction filler is a new type of chelating solid phase extraction filler with o-phenanthroline derivative as a bonded phase. The solid phase extraction filler has good adsorption effect on uranium in strong acid solution.

[0006] The technical scheme of the present application is: a chelating solid phase extraction filler, characterized in that the structure is:

[0007]

[0008] Wherein, PS is a polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) microsphere, n = 0-8, m = 0-10, X - is one or two or three of chloride ion, bromide ion, iodide ion.

[0009] The present application also provides a preparation method of the above chelating solid phase extraction filler, characterized by comprising the following steps:

[0010] (1) Synthesis of 1,10-phenanthroline derivative chelating ligand:

[0011] ① Synthesis of 1,10-phenanthroline derivative chelating ligand: ① 1,10-phenanthroline-2,9-dicarboxylic acid is added to DMF, and then heated to 40-80°C. Then add N'N-carbonyldiimidazole (CDI) at 25-70°C for 2h. Then add compound 1 drop by drop at 20-30°C, and then stir the reaction at room temperature for 1-5 days. After the reaction is completed, the reaction solvent is removed by reduced pressure distillation. Add 1-1.5 mol / L Na2CO3 solution to the residue, and place it at 0-10°C for 8-16 hours. The obtained precipitate is washed with water and diethyl ether, then dissolved in a mixed solvent, the solution is filtered to remove insoluble impurities, and the solvent is removed by rotary evaporation to obtain compound 2.

[0012] ② Compound 3 is dissolved in an organic solvent, and then slowly added to the compound 2 solution dissolved in a mixed solvent. Then, the solution is stirred at 10-50°C for 6-24h, and the temperature is raised to 50-80°C for 1-4 days. Then add diisopropylethylamine and stir for 1-4h, then remove the solvent by reduced pressure distillation, and wash the residue with a non-polar solvent. The obtained product is vacuum dried to obtain compound 4.

[0013] (2) Covalent modification of chelating ligand on the surface of polymer microspheres: Compound 4 is dissolved in a mixed solvent, and then PS-GMA microspheres are dispersed in the solution, and mechanically stirred at 50-80°C for 12-36h, centrifuged, and washed in sequence to obtain a chelating solid phase extraction filler.

[0014] The structures of the above compound 1 and compound 2 are as follows:

[0015] Compound 1:

[0016]

[0017] Compound 2:

[0018]

[0019] wherein, m = 0-10.

[0020] The structures of the compound 3 and the compound 4 are as follows:

[0021] Compound 3:

[0022]

[0023] Compound 4:

[0024]

[0025] wherein, n = 0-8, m = 0-10, X is one or two or three of chlorine atom, bromine atom, iodine atom.

[0026] Further, the use amount ratio of the 1,10-phenanthroline-2,9-dicarboxylic acid to DMF in step (1) ① is 1:10-1:50 (m / v, g / mL).

[0027] Further, the use amount ratio of the 1,10-phenanthroline-2,9-dicarboxylic acid to N'N-carbonyldiimidazole in step (1) ① is 1:1-1:5 (n / n, molar ratio).

[0028] Further, the use amount ratio of the 1,10-phenanthroline-2,9-dicarboxylic acid to the compound 1 in step (1) ① is 1:1-1:5 (n / n, molar ratio).

[0029] Further, the use amount ratio of 1 mol / L Na2CO3 to the 1,10-phenanthroline-2,9-dicarboxylic acid in step (1) ① is 10:1-100:1 (v / m, mL / g).

[0030] Further, the mixed solvent in step (1) ①, ② and step (2) is any two or more of methanol, ethanol, acetonitrile, acetone, and each has a volume content of at least 20%, wherein the use amount ratio of the mixed solvent to the compound 2 in step (1) ② is 20:1-100:1 (v / n, mL / mmol), and the use amount ratio of the mixed solvent to the compound 4 in step (2) is 5:1-100:1 (v / n, mL / mmol).

[0031] Further, the organic solvent in step (1) ② is one of methanol, ethanol, acetonitrile, acetone, and tetrahydrofuran, and the use amount ratio of the organic solvent to the compound 3 is 3:1-10:1 (v / m).

[0032] Further, the use amount ratio of the compound 2 to the compound 3 in step (1) ② is 1:2-1:3 (n / n).

[0033] Further, the use amount ratio of the compound 3 to the diisopropyl ethylamine in step (1) ② is 1:1-1:3 (n / n).

[0034] Further, the non-polar solvent in step (1) ② is one or two or more of petroleum ether, cyclohexane and n-hexane.

[0035] Further, the use amount ratio of the compound 4 to the PS-GMA in step (2) is 0.5-5 mmol of the compound 4 per gram of the PS-GMA.

[0036] The chelating solid phase extraction filler is prepared by covalently bonding a kind of phenanthroline derivative chelating ligand to the surface of polystyrene polymer microspheres. The filler has good separation effect on uranium and rare earth elements in a strong acid solution, has strong adsorption selectivity for uranium, and is particularly suitable for extraction recovery of uranium in strong acid spent fuel digestion solution and high-efficiency separation of uranium and fissile product lanthanide series elements. The solid phase extraction method based on the new chelating ion solid phase extraction filler has the advantages of rapid separation, good selectivity, excellent adsorption effect of uranium in a strong acid environment, and the like, and has good application potential in the fields of efficient treatment of spent fuel and burnup analysis.

[0037] Beneficial effects:

[0038] Compared with the prior art, the present application has the following characteristics:

[0039] 1. Novel structure, the present application covalently bonds a phenanthroline derivative chelating ligand to the surface of polymer microspheres, and the prepared filler has good structural stability and acid resistance.

[0040] 2. The filler prepared by the method has excellent adsorption performance for uranium in an acid solution.

[0041] 3. The filler prepared by the method has good separation capacity for uranium and rare earth elements in an acid solution.

[0042] 4. The filler has great application potential and high application value in the recovery of spent fuel and the removal of uranium in rare earth ore. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Trend of adsorption rate of chelating solid phase extraction filler 1 for uranium and four kinds of rare earth elements with change of nitric acid concentration in solution DETAILED DESCRIPTION

[0044] In order to make the purpose, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below in combination with examples. Several embodiments of the present application are given in the examples. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0045] The preparation method of the chelating solid-phase extraction filler has the following specific preparation steps:

[0046] I. Preparation method of the chelating solid-phase extraction filler:

[0047] (1) Synthesis of 1,10-phenanthroline derivative chelating ligand:

[0048] ① Synthesis of 1,10-phenanthroline derivative chelating ligand: ① 1,10-phenanthroline-2,9-dicarboxylic acid is added to DMF, and then heated to 40-80℃. Then N'N-carbonyldiimidazole (CDI) is added and reacted at 25-70℃ for 2h. Then compound 1 is added dropwise at 20-30℃, and then stirred at room temperature for 1-5 days. After the reaction is completed, the reaction solvent is removed by reduced pressure distillation. 1 mol / L Na2CO3 solution is added to the residue, and placed at 0-10℃ for 8-16h. The obtained precipitate is washed with water and diethyl ether, then dissolved with a mixed solvent, and the solution is filtered to remove insoluble impurities. The solvent is removed by rotary evaporation to obtain compound 2.

[0049] The amount ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to DMF used is 1:10-1:50 (m / v, g / mL); the amount ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to N'N-carbonyldiimidazole used is 1:1-1:5 (n / n, molar ratio); the amount ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to compound 1 used is 1:1-1:5 (n / n, molar ratio). The amount ratio of 1-1.5 mol / L Na2CO3 used to the amount of 1,10-phenanthroline-2,9-dicarboxylic acid used is 10:1-100:1 (v / m, mL / g).

[0050] The mixed solvent used is any two or more of methanol, ethanol, acetonitrile and acetone, and each has a volume content of at least 20%.

[0051] The structures of the above compound 1 and compound 2 are as follows:

[0052] Compound 1:

[0053]

[0054] Compound 2:

[0055]

[0056] wherein m = 0-10.

[0057] (2) Compound 3 is dissolved in an organic solvent, and then slowly added dropwise to a solution of compound 2 dissolved in a mixed solvent. Subsequently, the solution is stirred at 10-50°C for 6-24h, and the temperature is raised to 50-80°C for 1-4 days. Then diisopropylethylamine is added and stirred for 1-4h, followed by removal of the solvent under reduced pressure, and the residue is washed with a non-polar solvent. The resulting product is dried under vacuum to produce compound 4.

[0058] wherein the mixed solvent used is any two or more of methanol, ethanol, acetonitrile, acetone, and the use amount ratio of the mixed solvent to compound 2 is 20:1-100:1 (v / n, mL / mmol); the organic solvent used is one of methanol, ethanol, acetonitrile, acetone, and tetrahydrofuran, and the use amount ratio of the organic solvent to compound 3 is 3:1-10:1 (v / m); the non-polar solvent used is one of petroleum ether, cyclohexane, and n-hexane.

[0059] The use amount ratio of compound 2 to compound 3 is 1:2-1:3 (n / n), and the use amount ratio of compound 3 to diisopropylethylamine is 1:1-1:3 (n / n).

[0060] The structures of the above compound 3 and compound 4 are as follows:

[0061] Compound 3:

[0062]

[0063] Compound 4:

[0064]

[0065] wherein n = 0-8, m = 0-10, and X is one of chlorine atom, bromine atom, and iodine atom.

[0066] (2) Covalent modification of chelating ligands on the surface of polymer microspheres: Compound 4 is dissolved in a mixed solvent, and then PS-GMA is dispersed in the solution, and mechanical stirring is performed at 50-80°C for 12-36h, followed by centrifugation, and washing is sequentially used to produce a chelating solid-phase extraction filler.

[0067] wherein the use amount ratio of compound 4 to PS-GMA is 0.5-5 mmol of compound 4 per gram of PS-GMA.

[0068] Specific implementation

[0069] The content of the present application and the positive effects brought by the present application will be described in the following specific implementation.

[0070] Example 1

[0071] (1) Synthesis of 1,10-phenanthroline derivative chelating ligand: ① 4.5 g (16.8 mmol) of 1,10-phenanthroline-2,9-dicarboxylic acid was added to 95 mL of DMF (not completely dissolved, a yellowish suspension), then heated to 45°C. Then 8.55 g (52.73 mmol) of CDI was added in 5 equal portions (foam appeared on the surface of the solution during the addition, and bubbles were released), and reacted at 45°C for 2 h. Then 4.30 mL (36.0 mmol) of N-(3-aminopropyl)imidazole was added dropwise at 20°C, and then the reaction was stirred at room temperature for 4 days (the solution gradually turned into a transparent light brown color during the dropwise addition). After the reaction was completed, 50 mL of water was added to the reaction solution, and the DMF was removed under reduced pressure. 200 mL of 1 mol / L Na2CO3 was added to the residue, and left overnight (12 h) at 5°C. The obtained precipitate was washed with water and ether in turn, then dissolved in 50 mL of a mixed solvent of acetonitrile / ethanol (v / v = 1 / 1), the solution was turbid yellow, the precipitate was removed by filtration, a clear yellow solution was obtained, the solvent was removed by rotary evaporation, a brown liquid was obtained, which was left overnight (12 h) at 60°C, and the liquid solidified into a yellow-white solid, which was 2,9-di(N-(1-imidazolyl)propylamino carbonyl)-1,10-phenanthroline.

[0072] ② 2.34 g (10.05 mmol) of 4-bromo-butylamine hydrobromide was dissolved in 10 mL of acetonitrile, then slowly added dropwise to 90 mL of an acetonitrile / ethanol (v / v = 1 / 1) solution containing 2.0 g (4.15 mmol) of 2,9-di(N-(1-imidazolyl)propylamino carbonyl)-1,10-phenanthroline. Then the solution was stirred at 20°C for 12 h, and then reacted at 75°C for 2 days. Then 12 mmol of diisopropylethylamine was added and stirred for 2 h, then the solvent was removed under reduced pressure, and the residue was washed with n-hexane. The obtained product was dried under vacuum, then used for modification of polymer microspheres. The obtained product chelating ligand was confirmed by Q-TOF mass spectrometry, nuclear magnetic resonance hydrogen spectrum, and elemental analysis, and the structure is shown in the following figure:

[0073]

[0074] The product was characterized by Q-TOF mass spectrometry in positive ion mode, and the mass-to-charge ratio of [C 34 H 46 N 10 O2] 2+ was m / z = 392.6084.

[0075] (2) Covalent modification of chelating ligand on the surface of polymer microspheres: 5 mmol of the product obtained in step 2 above was dissolved in 20 mL of acetonitrile + 15 mL of ethanol mixed solvent, followed by 2.5 g of PS-GMA (polystyrene-divinylbenzene-glycidyl methacrylate, average particle size 70 μm, average pore size 50 nm) dispersed in the solution, and reacted at 65 °C for 24 h under mechanical stirring. After centrifugation, the product was washed with ethanol, water, and acetone in sequence to obtain chelating solid-phase extraction filler 1. The average particle size of the obtained chelating solid-phase extraction filler 1 was 70 μm, the average pore size was 50 nm, the specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. The specific surface area was 250 m2 / g. 2 The specific surface area was 250 m2 / g. 2 The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. 2 The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared.

[0076] The epoxy resin filler PS-GMA used was prepared according to the synthesis method described in the literature (D. Yuan, B. Huang / Catalysis Communications 18 (2012) 126-131).

[0077] Example 2

[0078] The difference from Example 1 was that equimolar 2-imidazol-1-ylethanamine was used instead of N-(3-aminopropyl)imidazole. Finally, chelating solid-phase extraction filler 2 was prepared, and the structural diagram thereof is shown in the following figure. The average particle size of the obtained chelating solid-phase extraction filler 2 was 73 μm, the average pore size was 50 nm, the specific surface area was 223 m2 / g, and the chelating ligand bonding density was 0.05 mmol / g. The obtained chelating solid-phase extraction filler 2 was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. 2 The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared.

[0079]

[0080] Example 3

[0081] The difference from Example 2 was that equimolar 2-bromoethanamine hydrobromide was used instead of 4-bromo-butylamine hydrobromide. Finally, chelating solid-phase extraction filler 3 was prepared, and the structural diagram thereof is shown in the following figure. The average particle size of the obtained chelating solid-phase extraction filler 3 was 68 μm, the average pore size was 50 nm, the specific surface area was 246 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler 3 was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared. 2 The specific surface area was 230 m2 / g, and the chelating ligand bonding density was 0.03 mmol / g. The obtained chelating solid-phase extraction filler was characterized by elemental analysis and infrared spectroscopy, proving that it was successfully prepared.

[0082]

[0083] Example 4

[0084] The difference from Example 1 is that equimolar 6-bromo-hexylamine hydrobromide was used instead of 4-bromo-butylamine hydrobromide. The final chelated solid-phase extraction packing 4 was prepared, and its structural schematic diagram is shown in the figure below. The obtained chelated solid-phase extraction packing 4 has an average particle size of 71 μm and an average pore size of... The specific surface area is 231 m². 2 / g, with a chelated ligand bonding density of 0.02 mmol / g. The obtained chelated solid-phase extraction packing material 4 was successfully prepared by elemental analysis and infrared spectroscopy characterization.

[0085]

[0086] Example 5

[0087] The adsorption performance of chelated solid-phase extraction packing material 1 on uranium and lanthanides in solutions with different acidities was tested, including the following steps:

[0088] First, a series of mixed aqueous solutions with different nitric acid concentrations (0.005, 0.025, 0.050, 0.250, 0.500, 1.000, 1.500 mol / L) were prepared, each containing the same concentration of uranium (47.6 mg / L) and four rare earth element solutions (La, 43.6 mg / L; Sm, 34.2 mg / L; Yb, 47.9 mg / L; Y, 22.6 mg / L). 20 mL of each of these solutions with different nitric acid concentrations was taken, and then 10 mg of the chelate solid-phase extraction packing material 1 prepared in Example 1 was added. After uniform dispersion, the mixture was shaken and adsorbed in a rotary culturer for 2 h. After adsorption, the mixture was allowed to stand for 10 min, and 2 mL of the supernatant was collected in a centrifuge tube. The remaining rare earth element content in the supernatant was determined using ICP-MS. The adsorption efficiency of the chelate solid-phase extraction packing material 1 for uranium and the four rare earth element solutions containing different nitric acid concentrations was then calculated. The trend of adsorption efficiency with nitric acid concentration is shown below. Figure 1 As shown. The adsorption rate of rare earth elements and uranium by the chelate solid-phase extraction packing is calculated as follows: (Rare earth element concentration in the initial solution - Rare earth element concentration in the supernatant after adsorption) ÷ Rare earth element concentration in the initial solution.

[0089] from Figure 1 It can be seen that the adsorption capacity of the four rare earth elements on chelated solid-phase extraction packing 1 decreases with increasing nitric acid concentration in the sample solution, while the adsorption capacity of chelated solid-phase extraction packing 1 on UO2 decreases. 2+ The adsorption capacity gradually increases with increasing acid concentration. When the nitric acid concentration in the solution reaches 1.500 mol / L, the adsorption capacity of the chelated solid-phase extraction packing material for UO2 increases. 2+ The adsorption rate can reach over 91%.

[0090] Example 6

[0091] In the solid phase extraction mode, the chelating solid phase extraction filler 1 was tested for adsorption performance on uranium in simulated reactor spent fuel, including the following steps:

[0092] First, 0.5 g of the chelating solid phase extraction filler 1 prepared in Example 1 was loaded into a 3 mL SPE column tube (inner diameter 5.6 mm, length 56.5 mm), then washed with 10 mL of water, and then equilibrated the solid phase column with 2M nitric acid solution at a flow rate of 0.5 mL / min for 30 min. 0.2 mL of simulated spent fuel digestion solution containing 1 mol / L and 2 mol / L nitric acid, respectively (composition as shown in Table 1), was loaded onto the solid phase column at a flow rate of 0.2 mL / min, and then the column was washed with the same concentration of nitric acid solution for 10 mL, and the effluent was collected for testing the content of uranium. The adsorption effect of the chelating solid phase extraction filler 1 on uranium in the simulated reactor spent fuel is shown in Table 2.

[0093] Table 1: Element content in simulated light water reactor spent fuel

[0094]

[0095] Table 2: Adsorption effect of chelating solid phase extraction filler 1 on uranium in simulated reactor spent fuel with different acidity

[0096]

[0097] The adsorption rate of the chelating solid phase extraction filler on uranium = (U content in the simulated spent fuel loading solution - U content in the effluent) ÷ U content in the simulated spent fuel loading solution

[0098] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0099] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as limiting the scope of the patent of the present application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for preparing a chelated solid-phase extraction packing material, characterized in that, include: The chelating solid-phase extraction packing material has the following schematic diagram: ； Wherein, PS is polystyrene-divinylbenzene-glycidyl methacrylate microspheres, n=0~8, m=0~10, X - It consists of one, two, or three of the chloride, bromide, and iodide ions; The preparation method of the chelated solid-phase extraction packing material is characterized by comprising the following steps: (1) Synthesis of chelating ligands of 1,10-phenanthroline derivatives: Synthesis of chelating ligands of 1,10-phenanthroline derivatives: ① 1,10-phenanthroline-2,9-dicarboxylic acid was added to DMF and heated to 40-80 °C; then N'N-carbonyldiimidazole (CDI) was added and reacted at 25-70 °C for 1-4 h; then compound 1 was added dropwise at 20-30 °C and stirred at room temperature for 1-5 days; after the reaction was completed, the reaction solvent was removed by vacuum distillation; 1-1.5 mol / L Na2CO3 solution was added to the residue and placed at 0-10 °C for 8-16 h; the precipitate was washed successively with water and diethyl ether and then dissolved in a mixed solvent; the solution was filtered to remove insoluble impurities, and the solvent was removed by rotary evaporation to obtain compound 2; ② Compound 3 was dissolved in an organic solvent and then added dropwise to a solution of compound 2 dissolved in a mixed solvent; the solution was then stirred at 10-50 °C for 6-24 h and heated to 50-80 °C for 1-4 days; then diisopropylethylamine was added and stirred for 1-4 h, followed by vacuum distillation to remove the solvent and washing the residue with a nonpolar solvent; the resulting product was dried under vacuum to obtain compound 4; (2) Covalent modification of chelating ligands on the surface of polymer microspheres: Compound 4 was dissolved in a mixed solvent, and then PS-GMA microspheres were dispersed in the solution. The reaction was mechanically stirred at 50-80 °C for 12-36 h, centrifuged, and washed sequentially to obtain chelated solid-phase extraction packing material. The structures of compound 1 and compound 2 are as follows: Compound 1: ； Compound 2: ； Where m = 0~10; The structures of compounds 3 and 4 are as follows: Compound 3: ； Compound 4: ； Where n = 0~8, m = 0~10, and X is one, two, or three of the following: chlorine, bromine, and iodine atoms.

2. The method as described in claim 1, characterized in that: The ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to DMF (N,N-dimethylformamide) in step (1) ① is 1:10~1:50, mL / g, and the molar ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to N'N-carbonyldiimidazole is 1:1~1:5; The molar ratio of 1,10-phenanthroline-2,9-dicarboxylic acid to compound 1 is 1:1 to 1:5; The ratio of the amount of 1-1.5 mol / L Na2CO3 solution used in step (1) ① to the amount of 1,10-phenanthroline-2,9-dicarboxylic acid is 10:1~100:1, g / mL.

3. The method as described in claim 1, characterized in that: The polystyrene-divinylbenzene-glycidyl methacrylate microspheres have a particle size of 40-100 μm, a pore size of 50-200 Å, and a specific surface area of ​​100-500 m². 2 / g, chelated functional group density 0.01-0.1 mmol / g.

4. The method as described in claim 1, characterized in that: The mixed solvent mentioned in steps (1) ①, ② and step (2) is any two or more of methanol, ethanol, acetonitrile and acetone, and the volume content of each is at least 20%. In step (1) ②, the ratio of the mixed solvent to compound 2 is 20:1 to 100:1, and in step (2), the ratio of the mixed solvent to compound 4 is 5:1 to 100:

1.

5. The method as described in claim 1, characterized in that: The organic solvent mentioned in step (1) ② is one of methanol, ethanol, acetonitrile, acetone, and tetrahydrofuran. The ratio of the organic solvent to compound 3 is 3:1 to 10:1, mL / g.

6. The method as described in claim 1, characterized in that: The ratio of compound 2 to compound 3 used in step (1) ② is 1:2 to 1:3; The ratio of compound 3 to diisopropylethylamine in step (1) ② is 1:1 to 1:

3.

7. The method as described in claim 1, characterized in that: The non-polar solvent mentioned in step (1) ② is one or more of petroleum ether, cyclohexane, and n-hexane; The ratio of compound 4 to PS-GMA in step (2) is 0.5-5 mmol of compound 4 per gram of PS-GMA.

8. The method as described in claim 1, characterized in that: PS is polystyrene-divinylbenzene-glycidyl methacrylate microspheres, n = 1~3, m = 1~5; m = 0~3 in compound 2; n = 1~3, m = 0~3 in compound 3.

9. A chelation solid-phase extraction packing material prepared by the method of any one of claims 1-8.

10. A chelating solid-phase extraction packing material according to claim 9 for separating uranium from rare earth elements in acidic solution.

11. The application of the chelated solid-phase extraction packing material of claim 9 in the uranium adsorption process in spent fuel digester of a reactor.

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