CN115267878A - Resin for separating and detecting uranium and preparation method thereof - Google Patents

Abstract

The invention discloses a resin for separating and detecting uranium and a preparation method thereof. The invention relates to a spherical particle with the particle diameter of several microns to hundreds of microns, which comprises a base material, a scintillating substance, a wave-transfer agent and a functional group, wherein the base material is polymerized by an unsaturated matrix monomer containing an active group, the wave-transfer agent is any one of 1, 4-bis (5-phenyloxazole) benzene or-bis- (sigma-methylstyrene) benzene, the scintillating substance is 2, 5-diphenyloxazole or bis (2-methylstyrene) benzene, and the functional group is an adsorbing material capable of selectively adsorbing and enriching uranium. The plastic scintillation resin has the advantages of good physical and chemical stability, long-time storage capacity, no toxicity, easy processing, simple and convenient synthesis method and good stability, and has a novel material with separation and detection performance, so that the uranium is separated and enriched, and meanwhile, the on-line detection can be carried out.

Description

Resin for separating and detecting uranium and preparation method thereof

Technical Field

The invention relates to a resin, in particular to a resin for separating and detecting uranium and a preparation method thereof.

Background

Nuclear energy with high efficiency and high energy density as clean energy is an effective means for solving the problem of climate warming. However, in the whole nuclear fuel circulation process (i.e. uranium mining, uranium purification and conversion, manufacturing and decommissioning of fuel assemblies in nuclear power plants, etc.), a large amount of uranium waste liquid is generated, which poses a potential threat to the ecological environment, and therefore, the uranium waste liquid needs to be treated before being discharged into the environment. However, in the process of treating a large amount of uranium-containing waste liquid, uranium can form aerosol in the air, and operators are directly injured. Therefore, in order to guarantee the personal safety of related workers and finally realize the effective protection of the ecological environment, it is necessary to establish an online and rapid measuring method for the uranium concentration in the operating environment.

The prior radionuclide separation method mainly comprises an ion exchange method, a solvent extraction method, an extraction chromatography method, an adsorption method and the like. The analysis method mainly comprises an alpha energy spectrum method, an inductively coupled plasma emission spectrometry method, an inductively coupled plasma mass spectrometry method, a liquid scintillation counting method and the like.

The ion exchange method has the advantages of high selectivity, simple and convenient operation, small pollution, no waste and the like, so the ion exchange method is widely used for separating and enriching uranium. For example, in the process of uranium ore mining, the uranium solution obtained by the acid leaching method can be separated by using strong-base anion exchange resin, and then is leached by using proper leacheate to obtain the high-purity uranium solution. Extraction of trace uranium from large amount of thorium by Chengmei, li Zheng, he Shuhua, zhan ion exchange method 2016, 38 (03): 159-165]Dissolving uranium oxide and thorium oxide by concentrated hydrochloric acid, using Dowex 1X 8 anion exchange resin and Dowex 50X 8 cation exchange resin as ion exchangers, and successfully separating trace uranium from hectogram per liter of Th and other fission product elements by using leacheate of different types and concentrations by an ion exchange method, wherein the recovery rate of uranium is more than 98%, and the content of other elements is less than 0.05 mu g/L. However, commercial resins used in ion exchange processes generally have relatively small specific surface areas, are prone to swelling due to water absorption, and are broken, have poor mechanical strength, and have poor irradiation resistance and relatively high limitations. Solvent extraction is one of the most widely used methods in industry. The Purex process widely applied to the nuclear fuel post-treatment at present adopts a solvent extraction method, tributyl phosphate (TBP) is used as an extractant, and different elements can be successfully extracted from spent fuel liquid through extraction and back extraction for several times. Other extracting agents such as ionic liquid also have good extracting effect at present. Wu Kage et al [ Wu Kage, shenxing Hai, ionic liquid medium UO₂（CMPO）₃（NO₃）₂Mechanisms of assembly and CMPO extraction of uranium Nuclear and Radioactive chemistry 2021, 43 (02): 136-141]The use of the extractant N-octylphenyl-N, N-diisobutylaminocarbamoylmethylphosphine oxide (CMPO) in 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonyl imide salt (C)₂mimNTf₂) The mechanism of extracting uranyl radical ions provides important reference for the extraction of uranium by the ionic liquid of the system. Most of the organic solvents used in the solvent extraction methodThe extraction method is limited by the solvent extraction speed and can generate a large amount of toxic organic radioactive waste liquid. The adsorption method refers to a method for transferring nuclide to be enriched from one phase to another phase, and has the advantages of convenience, high efficiency, good selectivity, etc., chenui, etc. [ Chenui, bei xi, zheng Bo, xuwei ] the research of uranium adsorption performance by zirconium diethylenetriamine pentamethylenephosphonate]The novel organic porous hybrid material is synthesized by using diethylenetriamine pentamethylene phosphonic acid as a phosphine source and zirconium oxychloride as a zirconium source, and experiments prove that the novel material can efficiently remove uranium (VI) in an aqueous solution.

Among the commonly used analytical methods, alpha spectroscopy is a method of identifying and quantifying radionuclides using an alpha spectrometer to measure the alpha particles emitted by the sample during decay. Xiongxin Dai (Isotropic uronium analysis in urea samples by alpha spectrometry. J. RadioacalNucl. Chem., 2011, 289: 595-600]An analysis method for measuring the form and the content of uranium in the urine sample by using an alpha spectrometer is established. However, the measurement by the alpha spectroscopy has requirements on the form of a sample source, and the measurement by the analysis method usually requires enrichment, concentration, separation and purification or labeling treatment, so that the operation process is troublesome. Inductively coupled plasma emission spectrometers are a device that is widely used in various analytical fields and allows qualitative and quantitative analysis of over seventy elements, including the measurement of uranium in a sample. Offer Zeiri et al [ Offer Zeiri, noaFruchter, eyalElish, haim Gizbar, dror Shamir, itzhakSedgi. Determination of organic Ratio by ICP-OES Using Optimal Sensitivity Position analysis. Chem. 2021, 93, 12: 5123-5128]The most sensitive position of uranium isotope in a sample is analyzed by utilizing an inductively coupled plasma emission spectrometer, and the pair is realized²³⁵U and²³⁸quantitative analysis of U separately. C. Derrick Quarles et al [ C. Derrick Quarles, benjamin T. Manard, E. Miller Wylie, ning xu. Trace elementary analysis of bulk urea materials using an in-line automated sample preparation technique for ICP-OES. Talanta, 2018, 190: 460-465]Enrichment and IC Using U-TEVA resinAnd (3) P-OES analysis, wherein 21 different elements in the water sample are successfully analyzed, and the detection limit of uranium is 326 ng/mL. The inductively coupled plasma mass spectrometry and the emission spectroscopy are mainly different in that the mass spectrometry is mainly used for analyzing a large amount of trace elements, the detection limit is greatly reduced, but the sample preparation is complicated and the operation is complex. The liquid scintillation counting method is one of the most commonly used methods in radiochemical analysis, and the method for absolutely measuring the uranium content in uranium solution by using the Von Xiaonian, he Qian barge, chengzao, wangzhao Yang, guo Jianfeng and the liquid scintillation alpha spectroscopy method, the atomic energy science and technology, 2010, 44 (S1): 63-68]The activity of three isotopes in natural uranium is directly distinguished from an alpha spectrogram by using a liquid scintillation spectrometer with an alpha/beta screening function, the relative error is only 3.5 percent, and the absolute measurement of the liquid scintillation spectrometer on alpha nuclide is realized. However, the conventional liquid flash measurement generates radioactive organic waste, which is extremely difficult to dispose.

The traditional separation and analysis methods are independent from each other, so that the time for enrichment, separation and sample preparation and analysis is greatly prolonged, and the radiation to operators is increased. In order to shorten the operation time, it is necessary to establish a novel and integrated separation and analysis method. The flow injection separation is one of the mainstream automatic separation technologies, and the method has the advantages of simple operation, easy continuous automatic analysis, high analysis speed and high precision. Wang et al [ Wang Chang, shewang soldier, liujie, liujiantong, flow injection separation-atomic absorption spectrometry for measuring bioavailable Cr (VI) and Cr (III) in bottom mud ] analytical chemistry 2007, (03): 451-454] utilizes a flow injection separation technology to be used together with an atomic absorption spectrometry, so as to realize the simultaneous on-line separation and measurement of Cr (VI) and Cr (III) in the bottom mud, and the detection limits and the maximum relative standard deviations of Cr (VI) and Cr (III) are respectively 0.9 mu g/L, 6.4 percent, 2.7 mu g/L and 3.5 percent. For automated separation analysis of radionuclides, separation of plutonium, uranium, or neptunium [1.j. Qiao, x. Hou, p. Roos, m. Micro. (2011). High-throughput sequencing approach for multiplex determination of plutonium and platinum in environmental analysis using a volumetric analysis-exchange chromatography, low-throughput analysis Chemistry, 2011, 83 (1): 374-81;2. J.X.Qiao, X.L.Hou, P.roos, J.Lacher, M.Christl, Y.H.Xu.sequential injection for a synergistic determination of ultra Plutonium and platinum in nucleic acid with electrolyte Chemistry, 2013a, 85 (18): 8826-8833], coupled with ICP-MS, achieve fully automatic on-line separation analysis of radionuclides.

Although some exploration is carried out on automatic and integrated separation and analysis equipment at present, an integrated analysis system for radioactive nuclides is in short supply, and because the traditional liquid flash analysis cannot analyze a high-salinity sample and continuously measure the high-salinity sample, and organic radioactive waste liquid is generated in the analysis process, the difficulty and the workload of subsequent waste treatment are further improved, so that the research on a new material integrating separation, enrichment and measurement for a liquid flash instrument is very important.

Disclosure of Invention

The invention provides a scintillator resin which can solve the defects of the prior art, can replace scintillation liquid, can separate and enrich uranium and can be directly measured in a scintillation counter, a preparation method and specific application.

The resin for separating and detecting uranium comprises a base material, a scintillation substance, a wave-transfer agent and a functional group, wherein the base material is formed by polymerizing an unsaturated matrix monomer containing an active group, the wave-transfer agent is any one of 1, 4-bis (5-phenyloxazole) benzene or-bis- (sigma-methylstyrene) benzene, the scintillation substance is 2, 5-diphenyloxazole or bis (2-methylstyrene) benzene, and the functional group is an adsorption material capable of selectively adsorbing and enriching uranium.

Preferably, the matrix monomer in the resin is styrene or/and divinylbenzene, the scintillation substance is 2, 5-diphenyloxazole, and the functional group is di- (2-ethylhexyl) phosphate. Preferably, the mass ratio of the styrene to the divinylbenzene in the matrix monomer is 3: 1-1: 3.

The preparation method of the resin comprises the following steps: respectively adding 0.50-3.00% of 2, 5-diphenyl oxazole, 0.01-0.03% of 1, 4-bis (5-phenyloxazole) benzene or equivalent p-bis- (sigma-methyl styryl) benzene and 0.5-1.5% of azobisisobutyronitrile into the mixed solution of styrene or/and divinylbenzene, and dissolving and shaking uniformly for later use; preparing 20 g/L gelatin and 1.7 g/L CaCO₃0.9 g/L sodium dodecyl sulfate solution; and (2) adding 1200-195 mL of deionized water into 5-20 mL of the prepared mixed solution, stirring and heating to 60 ℃, adding 1-20 mL of styrene solution, slowly raising the temperature to 70-80 ℃, continuously reacting, after the reaction is stopped, washing the product with warm water, and drying to obtain the product.

In the preparation method, the resin with different particle sizes, different particle sizes and different separation effects can be obtained by adjusting the reaction temperature, the reaction time, the stirring speed, the relative proportion of water and an organic phase in the raw materials, the proportion of gelatin \ calcium carbonate \ sodium dodecyl sulfate dispersant, the content of the adsorbent and other factors.

The resin can be used for separating uranium and detecting uranium, and particularly realizes on-line uranium detection.

The plastic scintillator resin of the present invention is an excellent material for many different types of scintillators because of its low cost and simple processing. When a solution containing the radionuclide uranium comes into contact with the scintillation resin, the uranium is trapped in the resin by selective binding to functional groups, while other nuclides flow out through the resin bed. When the rays emitted by the natural uranium are emitted into the plastic scintillator matrix, the first luminescent substance is excited by the electrons emitted by the first luminescent substance to emit light, and meanwhile, the wave-shifting agent enables the emission wavelength of the final light to be matched with the photomultiplier tube, so that the optical signal is converted into an electrical signal for detection, and the purpose of integrating enrichment and detection is achieved.

The plastic scintillation resin has similar composition to liquid scintillator, is white solid micro spherical granular material prepared through adding the first scintillation matter, wave shifter and adsorbent into plastic monomer and through polymerization, and has excellent physical and chemical stability, long storage period, no toxicity, easy processing, simple and fast synthesis process and high stability.

The resin synthesized by the invention is a novel material with separation detection performance, a column system is connected with a detection system, and the resin filled column can be used for carrying out on-line detection by the detection system after uranium is separated and enriched.

Drawings

FIG. 1 is a photomicrograph of a plastic scintillator resin prepared according to the present invention, the left is the resin without the extractant P204 added, and the right is the resin prepared according to the present invention.

FIG. 2 is an electron micrograph of a plastic scintillator resin prepared according to the present invention.

FIG. 3 is an infrared characterization of the plastic scintillator resin prepared in accordance with the present invention.

FIG. 4 is a fluorescence emission spectrum of the plastic scintillator resin of the present invention.

FIG. 5 shows the data of the static adsorption experiment of the plastic scintillator resin prepared by the present invention.

FIG. 6 is liquid scintillation data of a plastic scintillator resin made in accordance with the present invention.

Detailed Description

The following are several preferred embodiments of the present invention.

(one) preparation of resin

Example 1

1L of deionized water was taken, and 20 g of gelatin and 1.7g of CaCO were added₃0.9g of sodium dodecyl sulfate, and stirring and dissolving for later use.

Mixing 150 mL of styrene solution with 50 mL of divinylbenzene solution, adding 1.00% of PPO,0.02% of POPOP,2.0% of azobisisobutyronitrile and a certain amount of P204 solution, dissolving and shaking uniformly, and storing in a refrigerator for later use.

And (3) taking 20 mL of the aqueous phase solution, adding 140 mL of deionized water, adding 20 mL of styrene and divinylbenzene solution, slowly heating to 75 ℃, and reacting for 5 hours. And pouring the product into a 500 mL beaker, washing the product for a plurality of times by using warm water, filtering and drying to obtain the product.

Example 2

1L of deionized water was taken, and 20 g of sodium hydroxide was addedGlue, 1.7g CaCO₃0.9g of sodium dodecyl sulfate, and stirring and dissolving for later use.

50 mL of styrene solution and 50 mL of divinylbenzene solution are mixed, added with 1.00 percent of PPO,0.02 percent of POPOPOPOP, 2.0 percent of azobisisobutyronitrile and 14 percent of P204 solution, dissolved and shaken evenly, and stored in a refrigerator for standby.

And (3) taking 20 mL of the aqueous phase solution, adding 140 mL of deionized water, adding 20 mL of styrene and divinylbenzene solution, slowly heating to 75 ℃, and reacting for 5 hours. And pouring the product into a 500 mL beaker, washing the product with warm water for a plurality of times, filtering and drying the product to obtain the product.

Example 3

1L of deionized water was taken, and 20 g of gelatin and 1.7g of CaCO were added₃0.9g of sodium dodecyl sulfate, and stirring and dissolving for later use.

Mixing 50 mL of styrene solution with 50 mL of divinylbenzene solution, adding 1.00% of PPO,0.02% of POPOP,1.0% of azobisisobutyronitrile and 10% of P204 solution, dissolving and shaking uniformly, and storing in a refrigerator for later use.

And (3) taking 20 mL of the aqueous phase solution, adding 140 mL of deionized water, adding 20 mL of styrene and divinylbenzene solution, slowly heating to 75 ℃, and reacting for 5 hours. And pouring the product into a 500 mL beaker, washing the product for a plurality of times by using warm water, filtering and drying to obtain the product.

(II) the product characterization and related test results obtained in the above examples are as follows:

(1) Scintillator resin characterization

Fig. 1 is a microscope photograph (left) of a scintillator microsphere and a microscope photograph (right) of a scintillator resin, it can be seen that the surface of the scintillator microsphere without the adsorbent P204 is smooth, and obvious unevenness can be seen on the surface of the scintillator resin synthesized by the synthesis method established in the invention, which indicates successful grafting of the adsorbent. Meanwhile, the synthesized scintillation resin still has good transparency and can penetrate through different rays to support scintillation measurement as can be found from a microscope.

(2) Scintillation resin electron microscopy characterization

In fig. 2, a and b are scintillation microspheres without P204, c and d are graft-modified scintillator resins, and it can be seen that obvious wrinkles and voids appear on the resin surface after the extractant P204 is added, which is beneficial to the enrichment of uranium.

(3) Infrared characterization of scintillation resins

As can be seen from FIG. 3, when the material synthesized without the extractant was used as a control, it was found that the O-H bond peak of the extractant P204 appeared at 3200-3500 cm-1, and the P = O bond peak appeared at 1250-1350 cm-1, and it was determined that the extractant P204 was successfully grafted to the scintillator resin.

(4) Fluorescence of scintillator resins

As can be seen from FIG. 4, the fluorescence spectrum of the material was obtained by exciting the scintillation resin at 300 nm. As can be seen from the figure, the spherical material without the added scintillator has no excitation at 400-420 nm, but the synthesized scintillator has maximum excitation at 410 nm, which accords with the optimal detection range of the photomultiplier.

(III) static adsorption results of the resin of the invention

As is clear from FIG. 5, from the relationship between the adsorption pH and the adsorption amount in (b) of 5, the adsorption rate increased with the increase in the pH of the system and became stable up to 5.0, because the H content in the solution became stable with the increase in the pH⁺The concentration is reduced, competition with uranyl ions in the solution is weakened, and research results show that the optimal adsorption effect is achieved when the pH value is 5.0.

5 (c) shows that the adsorption equilibrium is reached after the material is adsorbed for 36 h, but 85 percent of the maximum equilibrium adsorption amount can be reached at 3 h, thereby providing guarantee for quick separation measurement, and simultaneously, the kinetic model of the material conforms to a quasi-second-order kinetic model (R)²=0.999)。

5 (d) is a relationship between a temperature change and a material adsorption rate, and it is understood from the graph that the material adsorption rate increases with an increase in temperature, which indicates that the adsorption reaction is an endothermic reaction, and the increase in temperature is advantageous for the forward progress of the adsorption reaction. Thermodynamic fitting indicates that the scintillation resin thermodynamic adsorption model conforms to the Freundlich model.

And 5 (e) is the selectivity of the scintillation resin to metal ions with the same concentration, and the figure shows that the scintillation resin has the optimal selectivity to uranyl ions and has a certain adsorption effect on zinc ions, but has a poor adsorption effect on other divalent metal ions, thereby laying a foundation for selective separation and measurement of the scintillation resin in the mixed metal ion solution.

(IV) scintillation measurement of scintillator resin liquid

It can be known from fig. 6 that, carry out the liquid scintillation to the chromatogram resin of having enriched different quality natural uranium and measure, obtain the relation of uranium quality and scintillation count, can find along with the improvement of the uranium quality that the resin of the same quality was enriched to, its count rate linear increase, consequently can obtain the concentration of unknown sample by the liquid scintillation count. The scintillation resin synthesized by the invention can achieve the effect of integrating enrichment and detection.

Claims (7)

1. A resin for separating and detecting uranium, wherein the resin is a spheroidal particle with the particle diameter of several microns to hundreds of microns, and comprises a base material, a scintillation substance, a wave-transfer agent and a functional group, the resin is characterized in that the base material is formed by polymerizing an unsaturated matrix monomer containing an active group, the wave-transfer agent is any one of 1, 4-bis (5-phenyloxazole) benzene or-bis- (sigma-methylstyrene) benzene, the scintillation substance is 2, 5-diphenyloxazole or bis (2-methylstyrene) benzene, and the functional group is an adsorbing material capable of selectively adsorbing and enriching uranium.

2. The resin according to claim 1, wherein: the matrix monomer is styrene or/and divinylbenzene, the scintillation substance is 2, 5-diphenyl oxazole, and the functional group is di- (2-ethylhexyl) phosphate.

3. The resin according to claim 2, wherein: the mass ratio of the styrene to the divinylbenzene in the matrix monomer is 3: 1-1: 3.

4. The method for preparing resin according to claim 3, wherein: respectively adding 0.50-3.00% of 2, 5-diphenyl oxazole, 0.01-0.03% of 1, 4-bis (5-phenyloxazole) benzene or equivalent p-bis- (sigma-methylstyrene) benzene and 0.5-1.5% of azodiDissolving isobutyronitrile, and shaking uniformly for later use; preparing 20 g/L gelatin and 1.7 g/L CaCO₃0.9 g/L of sodium dodecyl sulfate solution; and taking 5-20 mL of the prepared mixed solution, adding 1200-195 mL of deionized water, stirring, heating to 60 ℃, adding 1-20 mL of styrene solution, slowly raising the temperature to 70-80 ℃, continuously reacting, after the reaction is stopped, washing the product with warm water, and drying to obtain the product.

5. The method as claimed in claim 5, wherein the resin with different particle size and different separation effect is obtained by adjusting the reaction temperature, reaction time, stirring speed, the relative proportion of water and organic phase in the raw material, the proportion of gelatin, calcium carbonate and sodium dodecyl sulfate as dispersant and the content of adsorbent.

6. Use of any of the resins of claims 1 to 4 for separating uranium.

7. Use of any of the resins of claims 1 to 4 for detecting uranium.

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