Amphoteric nuclear-grade ion exchange resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of functional polymer materials, and particularly relates to amphoteric nuclear-grade ion exchange resin as well as a preparation method and application of the amphoteric nuclear-grade ion exchange resin. Functional groups for ion exchange simultaneously contain yttrium-doped zirconium phosphate cation exchange groups and pyridine quaternary ammonium base anion exchange groups, wherein the yttrium-doped zirconium phosphate cation exchange groups are bonded into polystyrene resin through acrylic acid groups. The resin has excellent high temperature resistance, radiation resistance and high anion and cation adsorption and exchange capacity, can be widely applied to the fields of nuclear power loop water purification, radioactive wastewater treatment, nuclear fuel post-treatment and the like, and solves the technical problem that the performance of traditional resin is severely degraded in an extreme environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional polymer materials, and particularly relates to an amphoteric nuclear-grade ion exchange resin as well as a preparation method and an application thereof, and is particularly suitable for ion separation and purification processes in extreme environments such as nuclear power plant loop water and radioactive wastewater treatment. BACKGROUND

[0002] In order to improve the applicability of ion exchange resins in harsh environments such as nuclear industry and high-temperature chemical industry, researchers have constructed inorganic-organic composite resins by introducing inorganic fillers to enhance the radiation resistance and thermal stability of the materials. However, the existing technology still has the problem that the inorganic fillers and the organic matrix are mainly combined by physical action, and the interface bonding force is insufficient. For example, the temperature-resistant resin disclosed in patent CN201910660793.2 bonds yttrium-zirconium composite oxide powder and the resin matrix through polyvinyl alcohol, and the interface is only physically adsorbed, which is easy to cause structural failure due to the falling off of the fillers under radiation or high temperature. Although the radiation resistance is improved by modifying zirconium phosphate in patent CN202411529437.4, the interface between zirconium phosphate and the resin is still mainly physically blended, and the interface separation will significantly reduce the ion exchange capacity and mechanical strength during long-term service. The above-mentioned technologies have not realized the chemical covalent bonding between the inorganic phase and the organic phase, and it is difficult to maintain a stable composite structure in complex environments, which limits the improvement of the temperature resistance and radiation resistance of the resins, and cannot meet the long-term use requirements in scenes such as nuclear-grade condensate water polishing and high-temperature medium separation. At the same time, due to the influence of the main chain of the styrene resin, the exchange groups of the anion resin are prone to Hofmann degradation, which reduces the exchange capacity. At the same time, chloromethyl ether, which is commonly used in the preparation process of the anion resin, is a highly toxic substance, which leads to a high environmental and safety risk for anion resin production enterprises. Therefore, it has important technical value and practical significance to develop a composite ion exchange resin with strong interface bonding, uniform dispersibility, environmentally friendly raw materials and multiple stability mechanisms. SUMMARY

[0003] In order to overcome the above-mentioned defects, the present application provides an amphoteric nuclear-grade ion exchange resin as well as a preparation method and an application thereof.

[0004] To solve the above technical problems, the first aspect of the present application adopts the following technical solution: An amphoteric nuclear-grade ion exchange resin, which is a polystyrene-based ion exchange resin, contains an acrylic acid spacer group in the resin main chain, and the functional groups in the ion exchange resin contain yttrium-doped zirconium phosphate cation exchange groups and pyridine quaternary ammonium base anion exchange groups.

[0005] Preferably, the yttrium-doped zirconium phosphate cation exchange group is bonded to the polystyrene resin through the acrylic acid spacer group.

[0006] The second aspect of the present application discloses a preparation method of the aforementioned amphoteric nuclear grade ion exchange resin, comprising the following steps: Step a) dispersing yttrium salt and zirconium salt in deionized water, adding acrylic phosphate derivative, phosphoric acid and polymerization inhibitor, stirring and transferring to a reaction kettle, reacting at 60-100 DEG C for 1-10 h, centrifuging and washing with water to obtain acrylic modified yttrium doped zirconium phosphate; Step b) preparing an aqueous phase containing dispersant and metal salt, uniformly mixing acrylic modified yttrium doped zirconium phosphate, styrene, vinylpyridine, crosslinking agent and initiator to obtain an oil phase reaction liquid, adding the oil phase reaction liquid to the aqueous phase under stirring, heating to 50-60 DEG C, stirring and reacting for 10-60 min, gradient heating to 90-95 DEG C, reacting for 7-12 h, and obtaining ion exchange resin white ball after filtration, washing, drying and screening processes; Step c) swelling the ion exchange resin white ball in a swelling agent, stirring, adding organic chloride, heating and reacting, filtering and washing with water to obtain amphoteric ion exchange resin; Step d) adding the amphoteric ion exchange resin to lye, stirring and reacting, and washing with water to obtain amphoteric nuclear grade ion exchange resin.

[0007] Preferably, the yttrium salt in step a) is one or more of yttrium nitrate, yttrium chloride and yttrium acetate; the zirconium salt is one or more of zirconium oxychloride, zirconium sulfate and zirconium nitrate; and the mass ratio of yttrium salt to zirconium salt is 0.2-0.3:1.

[0008] Preferably, the acrylic phosphate derivative in step a) is one of 2-hydroxyethyl methacrylate phosphate, methacrylic acid phosphate and 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate; the mass ratio of acrylic phosphate derivative, phosphoric acid and zirconium salt is 0.2-0.5:0.2-0.4:1; under this ratio, the acrylic phosphate, phosphoric acid and zirconium salt are co-precipitated, the molecular topological structure of zirconium phosphate is regulated, and yttrium is highly doped; the polymerization inhibitor is hydroquinone or p-hydroxyanisole, and the mass ratio of polymerization inhibitor to acrylic phosphate derivative is 0.01-0.1:1.

[0009] Preferably, the dispersant in the aqueous phase in step b) is polyvinyl alcohol or gelatin, the metal salt is sodium chloride, potassium chloride or magnesium chloride, and the mass ratio of dispersant, metal salt and deionized water in the aqueous phase is 1:(0.2-1):(50-200).

[0010] Preferably, the initiator in the oil phase reaction solution in step b) is one of benzoyl peroxide, ammonium persulfate, and 2,2'-azobis(2-methylpropionitrile), the crosslinking agent is one or a combination of the two of divinylbenzene and tri-vinylbenzene, the vinylpyridine is one or a combination of the two of 4-vinylpyridine, 2-vinylpyridine, and 2-methyl-5-vinylpyridine, the mass ratio of styrene, acrylic modified yttrium-doped zirconium phosphate, vinylpyridine, crosslinking agent, and initiator in the oil phase reaction solution is 1:(0.1-0.3):(0.1-0.4):(0.08-0.25):(0.01-0.1), and the mass ratio of the oil phase and the aqueous phase is 1:(20-200).

[0011] The use amounts of the acrylic modified yttrium-doped zirconium phosphate and the vinylpyridine relative to the styrene need to be controlled to prevent excessive use from causing the side chain space structure in the polymer to be hindered, thereby significantly reducing the stability. If the use amount of the vinylpyridine is too small, the anion mass exchange capacity is significantly reduced.

[0012] Preferably, the swelling agent in step c) is one of dichloroethane, N,N-dimethylformamide, and dimethyl sulfoxide, the mass ratio of the swelling agent to the ion exchange resin white ball is (0.3-2):1, the organic chloride is one of benzyl chloride and 2-chloroethylbenzene, the reaction temperature is 90-140°C, the reaction time is 2-8h, and the mass ratio of the added organic chloride to the ion exchange resin white ball is (0.02-0.2):1.

[0013] Preferably, the alkali solution in step d) is one of sodium hydroxide and potassium hydroxide, and the mass ratio of the alkali solution to the zwitterionic ion exchange resin is 1:(0.05-0.2).

[0014] The present application prepares the acrylic modified yttrium-doped zirconium phosphate through a hydrothermal reaction, uses the copolymerization of unsaturated groups to achieve strong bonding of the yttrium-doped zirconium phosphate to the polystyrene resin, grafts a pyridine group in the resin, and finally obtains the zwitterionic ion exchange resin through quaternization and transformation of the pyridine group.

[0015] The third aspect of the present application provides the use of the aforementioned zwitterionic ion exchange resin in the treatment of nuclear power plant loop water or radioactive wastewater and nuclear fuel reprocessing.

[0016] Advantages

[0017] (1) The zwitterionic ion exchange resin prepared by the present application contains the cation adsorption functional group zirconium phosphate and the anion exchange group quaternary ammonium salt, can realize the synchronous removal of anions and cations in wastewater, avoids the need to use a mixed bed system of anion and cation exchange resins in traditional wastewater treatment, reduces the bed height, and improves the treatment efficiency of the ion exchange resin bed.

[0018] (2) The application utilizes yttrium-doped zirconium phosphate to realize the regulation of the surface performance of zirconium phosphate, and improve the adsorption performance of zirconium phosphate on radioactive cations. In the preparation of yttrium-doped zirconium phosphate, acrylic phosphate and phosphoric acid are used for co-precipitation with zirconium salt to realize the regulation of the molecular topological structure of zirconium phosphate. The introduced discontinuous distribution of phosphorus-oxygen groups in the acrylic phosphate provides additional sites for the doping of yttrium, and high-concentration doping of yttrium can be realized without changing the integrity of the layered structure of zirconium phosphate, thereby improving the adsorption rate of the resin on cations.

[0019] (3) The application uses acrylic phosphate as a phosphoric acid precursor, which can graft an acrylic group on the surface of the formed yttrium-doped zirconium phosphate. Through copolymerization of acrylic acid and styrene, strong and efficient covalent bonding between zirconium phosphate and the styrene resin matrix is realized, and the stability of the zirconium phosphate component in the amphoteric nuclear ion exchange resin is improved. At the same time, the acrylic group can realize the local peeling of the zirconium phosphate layer, improve the diffusion rate of cations in the zirconium phosphate layer, and thereby improve the exchange rate of the resin on cations.

[0020] (4) The application uses vinylpyridine as a precursor of an anion exchange group, which is grafted in situ in the resin matrix through copolymerization. Then, through the quaternary amination reaction between pyridine and organic chlorides, a strong alkaline quaternary ammonium salt exchange group is obtained, avoiding the use of chloromethyl ether and other toxic substances in the traditional preparation process of anion exchange groups, and improving the environmental protection and safety of the resin preparation process.

[0021] (5) The application can introduce an acrylic group into the styrene resin skeleton through in-situ polymerization of various substances containing vinyl groups. At the same time, the yttrium-doped zirconium phosphate cation exchange group and the pyridine quaternary ammonium base anion exchange group are grafted on the styrene backbone, which can exert the electron-donating ability of yttrium-doped zirconium phosphate, improve the electronegativity of carbon atoms on the pyridine quaternary ammonium base, effectively inhibit the Hofmann degradation of the quaternary ammonium group, and improve the temperature resistance and radiation resistance of the anion exchange group. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in conjunction with specific examples.

[0023] Example 1

[0024] a) 16 g of yttrium nitrate, 80 g of zirconium oxychloride, 40 g of 2-hydroxyethyl methacrylate phosphate, 25 g of phosphoric acid, and 1 g of hydroquinone were dissolved in 300 mL of deionized water, stirred for 15 min, transferred to a reaction kettle, and reacted at 80℃ for 4 h. After centrifugation and washing with 1000 mL of deionized water, the acrylic-modified yttrium-doped zirconium phosphate was dried to obtain the acrylic-modified yttrium-doped zirconium phosphate; b) configuring a water phase containing 37.5 g of polyvinyl alcohol, 12.5 g of sodium chloride and 5000 mL of deionized water, stirring uniformly, obtaining a water phase, and configuring an oil phase reaction solution containing 100 g of styrene, 10 g of acrylic modified yttrium doped zirconium phosphate, 20 g of 2-vinylpyridine, 12.5 g of divinylbenzene, 2.5 g of trivinylbenzene and 2.5 g of benzoyl peroxide, adding the oil phase reaction solution into the water phase (the mass ratio of the oil phase and the water phase is 1:50), stirring, and heating to 55℃, stirring and reacting for 30 min, sequentially reacting at 65℃ for 30 min, at 75℃ for 1 h, at 85℃ for 1 h and at 90℃ for 7 h, and obtaining ion exchange resin white balls after the processes of filtering, washing, drying and sieving; c) adding 50 g of ion exchange resin white balls into 15 g of dichloroethane, swelling, stirring for 2 h, adding 1 g of benzyl chloride, reacting at 105℃ for 5 h, filtering and washing with water to obtain a zwitterionic ion exchange resin; d) adding 50 g of the zwitterionic ion exchange resin into 400 g of a 10wt% sodium hydroxide aqueous solution, stirring and reacting for 10 h, and washing with water to obtain a zwitterionic nuclear grade ion exchange resin.

[0025] Example 2

[0026] a) dissolving 15 g of yttrium chloride and 75 g of zirconium sulfate in 300 mL of deionized water, adding 22.5 g of 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, 16 g of phosphoric acid and 2 g of p-hydroxyanisole, stirring for 30 min, transferring into a reaction kettle, and reacting at 95℃ for 8 h, and obtaining acrylic modified yttrium doped zirconium phosphate after centrifugation, washing with 1500 mL of deionized water and drying; b) configuring a water phase containing 40 g of polyvinyl alcohol, 30 g of potassium chloride and 6000 mL of deionized water, stirring uniformly, obtaining a water phase, and configuring an oil phase reaction solution containing 100 g of styrene, 15 g of acrylic modified yttrium doped zirconium phosphate, 35 g of 4-styrylpyridine, 10 g of divinylbenzene and 7 g of benzoyl peroxide, adding the oil phase reaction solution into the water phase (the mass ratio of the oil phase and the water phase is 1:30), stirring, heating to 50℃, stirring and reacting for 30 min, sequentially reacting at 65℃ for 30 min, at 75℃ for 1 h, at 85℃ for 1.5 h and at 90℃ for 7.5 h, and obtaining ion exchange resin white balls after the processes of filtering, washing, drying and sieving; c) adding 50 g of ion exchange resin white balls into 50 g of N,N-dimethylformamide, swelling, stirring for 1 h, adding 10 g of 2-chloroethylbenzene, reacting at 130℃ for 2 h, filtering and washing with water to obtain a zwitterionic ion exchange resin; d) 50 g of the amphoteric ion exchange resin was added to 600 g of a 10 wt% sodium hydroxide aqueous solution, and stirred for 8 h, and washed with water to obtain a high-temperature and strong radiation resistant amphoteric core-stage ion exchange resin.

[0027] Example 3

[0028] a) 20 g of yttrium acetate, 85 g of zirconium oxychloride were dissolved in 500 mL of deionized water, 42 g of methyl methacrylate phosphate, 34 g of phosphoric acid and 1.7 g of hydroquinone were added, stirred for 11 h, transferred to a reaction kettle, reacted at 75°C for 4 h, centrifuged, washed with 2000 mL of deionized water, and dried to obtain acrylic acid modified yttrium doped zirconium phosphate; b) an aqueous phase was prepared by uniformly stirring 50 g of gelatin, 20 g of potassium chloride and 8000 mL of deionized water, and an oil phase reaction solution was prepared by uniformly stirring 100 g of styrene, 10 g of acrylic acid modified yttrium doped zirconium phosphate, 15 g of 2-vinylpyridine, 15 g of 2-methyl-5-vinylpyridine, 18 g of trivinylbenzene and 6.5 g of azobisisobutyronitrile, the oil phase reaction solution was added to the aqueous phase (the mass ratio of the oil phase to the aqueous phase was 1:50), stirred, and heated to 60°C, and stirred for 60 min, and then sequentially reacted at 75°C for 1 h, at 85°C for 1 h and at 90°C for 9 h, and then subjected to a filtration, washing, drying and sieving process to obtain ion exchange resin white balls; c) 50 g of the ion exchange resin white balls were added to 25 g of dimethyl sulfoxide, swelled, stirred for 4 h, 6 g of 2-chloroethylbenzene was added, and reacted at 110°C for 6 h, filtered, and washed with water to obtain an amphoteric ion exchange resin; d) 50 g of the amphoteric ion exchange resin was added to 600 g of a 10 wt% sodium hydroxide aqueous solution, and stirred for 8 h, and washed with water to obtain a high-temperature and strong radiation resistant amphoteric core-stage ion exchange resin.

[0029] Comparative Example 1 Without adding acrylic acid modified yttrium doped zirconium phosphate during suspension polymerization: step a) was omitted, and acrylic acid modified yttrium doped zirconium phosphate was not added in step b), and the other steps were the same as in Example 1.

[0030] Comparative Example 2 Yttrium modified zirconium phosphate particles were directly used without modification by acrylic acid phosphate ester, and step a) was replaced by dissolving 16 g of yttrium nitrate, 80 g of zirconium oxychloride in 300 mL of deionized water, adding 40 g of phosphoric acid, stirring for 15 min, transferring to a reaction kettle, and reacting at 80°C for 4 h, and then centrifuging, washing with 1000 mL of deionized water, and drying to obtain yttrium doped zirconium phosphate particles; and in step b), yttrium doped zirconium phosphate particles were used instead of acrylic acid modified yttrium doped zirconium phosphate, and the other steps were the same as in Example 1.

[0031] Comparative Example 3 The traditional anion exchange resin preparation method was adopted. In step b), instead of adding 2-vinylpyridine, a solution containing 37.5 g polyvinyl alcohol, 12.5 g sodium chloride, and 5000 mL deionized water was prepared and stirred until homogeneous to obtain an aqueous phase. Separately, an oil phase reaction solution containing 100 g styrene, 10 g acrylic acid-modified yttrium-doped zirconium phosphate, 12.5 g divinylbenzene, 2.5 g trivinylbenzene, and 2.5 g benzoyl peroxide was prepared. This oil phase reaction solution was added to the aqueous phase, stirred, and heated to 55°C. The reaction was continued for 30 min with stirring, followed by repeated reactions at 65°C for 30 min, 75°C for 1 h, 85°C for 1 h, and 90°C for 7 h. After filtration, washing, drying, and sieving, white ion exchange resin spheres were obtained. In step c), 50 g of the white ion exchange resin spheres were added to 15 g dichloroethane to swell, stirred for 2 h, then 100 g chloromethyl ether was added, stirred for 20 min, and then 20 g chloromethyl ether was added. Anhydrous zinc chloride was heated to 35°C and stirred for 6 hours. The mixture was filtered to obtain chloropolymer spheres. 250 mL of a 20% (w / w) trimethylamine aqueous solution was prepared, and 50 g of the chloromethylated resin complex prepared above was added. The pH of the mixed solution was adjusted to 8.5 using a 0.85 mol / L Na₂CO₃ aqueous solution. The mixture was stirred for 8 hours, filtered, and the filter cake was washed with deionized water until neutral to obtain nuclear-grade ion exchange resin. Other steps were the same as in Example 1.

[0032] Comparative Example 4 The oil phase reaction liquid formulation in the suspension polymerization process of Example 1 was changed to 100 g styrene, 3.2 g acrylic acid modified yttrium doped zirconium phosphate, 20 g 2-vinylpyridine, 12.5 g divinylbenzene, 2.5 g trivinylbenzene and 2.5 g benzoyl peroxide, and the other steps were the same as in Example 1.

[0033] Comparative Example 5 The hydroxyethyl methacrylate phosphate used in step a) of Example 1 was replaced with the same molar amount of vinyl diethyl phosphate, and the other steps were the same as in Example 1.

[0034] Performance Tests and Results The following performance tests were performed on the resins prepared in the above embodiments and comparative examples: 1) The anion exchange capacity of the prepared nuclear grade resin was determined according to the national standard (GB / T 5760-2000).

[0035] 2) The test method for cation adsorption rate is as follows: Add 5 g of resin to 100 mL of an aqueous solution containing cobalt, nickel, cesium and strontium ions (each ion has a mass fraction of 10 mg / L), stir and adsorb for 30 min. After filtering to remove the resin, test the total content of metal ions in the aqueous solution and calculate the cation adsorption rate.

[0036] 3) The temperature resistance of the resin is referenced in DL / T 953-2005. After heating in a 95℃ water bath for 100 h, the decrease rate of anion exchange capacity is tested.

[0037] 4) Radiation resistance A certain amount of resin sample was taken and placed in polyethylene plastic bottles. Sufficient deionized water was added, and the sample was irradiated with a 100 Gy 60Co radiation source for 2 hours. The decrease rate of anion exchange capacity was measured.

[0038] Table 1 Performance metrics of the examples and comparative examples

[0039] In the examples, the resin adsorbs metal ions rapidly, and a large amount of ions can be removed in just 30 minutes.

[0040] Compared with Example 1, Comparative Example 1 did not add acrylic acid-modified yttrium-doped zirconium phosphate, lacking cationic adsorption groups, thus the cationic adsorption rate was significantly reduced, and it could not effectively inhibit the Hoffmann degradation of quaternary ammonium groups, resulting in a significant decrease in temperature resistance and radiation resistance.

[0041] Compared with Example 1, Comparative Example 2 did not use phosphate acrylate modification. The lack of acrylic acid groups significantly degraded the cation adsorption rate, temperature resistance, and radiation resistance, and also reduced the anion mass exchange capacity to a certain extent.

[0042] Compared to Example 1, Comparative Example 3 uses a traditional anion exchange resin preparation method, which has higher toxicity and lower chloromethylation degree, resulting in a lower quaternization rate of trimethylamine. This leads to a significant difference in anion mass exchange capacity, temperature resistance, and radiation resistance compared to Example 1. Furthermore, the overall structural stability is reduced, which also reduces the cation adsorption rate.

[0043] Compared to Example 1, Comparative Example 4 changed the relative amount of acrylic acid-modified yttrium-doped zirconium phosphate, which resulted in the acrylic acid spacer groups not fully playing their spacer role. The electron-donating ability of yttrium-doped zirconium phosphate at this amount was insufficient to effectively inhibit the Hoffmann degradation of quaternary ammonium groups, and the temperature and radiation resistance decreased significantly. At the same time, the cation adsorption rate also decreased.

[0044] Compared to Example 1, Comparative Example 5 used diethyl vinyl phosphate instead of acetic acid, resulting in a decrease in cation adsorption rate, temperature resistance, and radiation resistance. This demonstrates that the acrylic acid group has a significant impact on cation adsorption rate, temperature resistance, and radiation resistance in this invention.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A zwitterionic nuclear-grade ion exchange resin, characterized in that, The zwitterionic-grade ion exchange resin is a polystyrene-based ion exchange resin. The functional groups in the ion exchange resin contain both yttrium-doped zirconium phosphate cation exchange groups and pyridine quaternary ammonium base anion exchange groups. The yttrium-doped zirconium phosphate cation exchange groups are bonded to the polystyrene resin through acrylic acid spacer groups.

2. The method for preparing an amphoteric nuclear-level ion exchange resin according to claim 1, characterized in that, Includes the following steps: Step a) Disperse yttrium salt and zirconium salt in deionized water, add acrylate phosphate derivative, phosphoric acid and polymerization inhibitor, stir and transfer to a reaction vessel, react at 60~100℃ for 1~10 h, centrifuge and wash with water to obtain acrylic acid modified yttrium doped zirconium phosphate; Step b) Prepare an aqueous phase containing a dispersant and a metal salt. Mix acrylic acid-modified yttrium-doped zirconium phosphate, styrene, vinylpyridine, a crosslinking agent, and an initiator evenly to obtain an oil phase reaction solution. Add the oil phase reaction solution to the aqueous phase with stirring, heat to 50-60℃, stir and react for 10-60 min, gradually increase the temperature to 90-95℃, and react for 7-12 h. After filtration, washing, drying, and sieving, obtain ion exchange resin white spheres. Step c) Add the white ion exchange resin balls to the swelling agent to swell, stir, add organic chloride, heat to react, filter, wash with water to obtain amphoteric ion exchange resin; Step d) Add the zwitterionic ion exchange resin to the alkaline solution, stir to react, and wash with water to obtain zwitterionic nuclear-grade ion exchange resin.

3. The method for preparing an amphoteric nuclear-level ion exchange resin according to claim 2, characterized in that, The yttrium salt mentioned in step a) is one or more of yttrium nitrate, yttrium chloride, and yttrium acetate; the zirconium salt is one or more of zirconium oxychloride, zirconium sulfate, and zirconium nitrate; the mass ratio of yttrium salt to zirconium salt is 0.2~0.3:

1.

4. The method for preparing an amphoteric nuclear-level ion exchange resin according to claim 2, characterized in that, The phosphate acrylate derivative mentioned in step a) is one of 2-hydroxyethyl methacrylate phosphate, methacrylate phosphate, and 2-methyl-2-acrylic-2-hydroxyethyl phosphate, and the mass ratio of the phosphate acrylate derivative, phosphoric acid, and zirconium salt is 0.2~0.5:0.2~0.4:1; the polymerization inhibitor is hydroquinone or p-hydroxyanisole, and the mass ratio of the polymerization inhibitor to the phosphate acrylate derivative is 0.01~0.1:

1.

5. The method for preparing an amphoteric nuclear-grade ion exchange resin according to claim 2, characterized in that, The dispersant in the aqueous phase mentioned in step b) is polyvinyl alcohol or gelatin, and the metal salt is sodium chloride, potassium chloride or magnesium chloride. The mass ratio of dispersant, metal salt and deionized water in the aqueous phase is 1:(0.2~1):(50~200).

6. The method for preparing an amphoteric nuclear-grade ion exchange resin according to claim 2, characterized in that, In step b), the initiator in the oil phase reaction solution is one of benzoyl peroxide, ammonium persulfate, and azobisisobutyronitrile; the crosslinking agent is one or a combination of divinylbenzene and trivinylbenzene; the vinylpyridine is one or a combination of 4-styrylpyridine, 2-vinylpyridine, and 2-methyl-5-vinylpyridine; the mass ratio of styrene, acrylic acid-modified yttrium-doped zirconium phosphate, vinylpyridine, crosslinking agent, and initiator in the oil phase reaction solution is 1:(0.1~0.3):(0.1~0.4):(0.08~0.25):(0.01~0.1); and the mass ratio of the oil phase to the aqueous phase is 1:(20~200).

7. The method for preparing an amphoteric nuclear-level ion exchange resin according to claim 2, characterized in that, The swelling agent mentioned in step c) is one of dichloroethane, N,N-dimethylformamide, and dimethyl sulfoxide. The mass ratio of the swelling agent to the white spheres of the ion exchange resin is (0.3~2):

1. The organochloride is one of benzyl chloride and 2-chloroethylbenzene. The reaction temperature is 90~140℃, the reaction time is 2~8h, and the mass ratio of the added organochloride to the white spheres of the ion exchange resin is (0.02~0.2):

1.

8. The method for preparing an amphoteric nuclear-grade ion exchange resin according to claim 3, characterized in that, The alkaline solution mentioned in step d) is either sodium hydroxide or potassium hydroxide, and the mass ratio of the alkaline solution to the zwitterionic exchange resin is 1:(0.05~0.2).

9. The use of the amphoteric nuclear-grade ion exchange resin according to claim 1 or 2 in the treatment of nuclear power plant loop water or radioactive wastewater, and in the reprocessing of nuclear fuel.

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