JP4587068B2 - Isotope separation method, isotope separation device, and isotope separation means - Google Patents

Description

The present invention relates to an alkali metal element (hereinafter referred to as a Group IA element in the periodic table excluding hydrogen) and an alkaline earth metal element (hereinafter referred to as a Group IIA element in the periodic table in the present invention). In more detail, the present invention relates to an alkali produced when an alkali metal element or an alkaline earth metal element and a cyclic compound such as crown ether or cryptand are complexed. The present invention relates to isotope separation in which isotopes are separated and concentrated using the isotope effect of metal elements or alkaline earth metal elements.

Among alkali metal elements and alkaline earth metal elements, lithium (Li), magnesium (Mg), potassium (K), calcium (Ca), rubidium (Rb), strontium (Sr) and barium (Ba) are a plurality of It exists in nature as a mixture containing stable isotopes at a constant abundance ratio, and these stable isotopes are used as labeling compounds in the biological / medical fields, for example, today. For this reason, isotope separation of alkali metal elements or alkaline earth metal elements has become an important technique.

Furthermore, in the medical field, radioisotopes of alkali metal elements and alkaline earth metal elements are useful as therapeutic agents and diagnostic agents, and in sterilization, radiotherapy, radiation measurement, radiation chemistry, etc., the use of radiation sources In these fields, techniques for separating stable isotopes of alkali metal elements or alkaline earth metal elements from radioisotopes are required.

Moreover, given the alkali metal element or an alkaline earth metal element in the reactor, these elements, as fission products are produced in a nuclear reactor, which is in a mixture with the radioactive isotope and the stable isotope . For this reason, it is necessary to treat the generated alkali metals and alkaline earth metals. In the treatment and disposal of these elements, stable isotopes and radioactive materials are used for reasons such as volume reduction of radioactive waste. It is desired to separate isotopes. Moreover, because of the demand in the field mentioned above, the radioactive isotopes of the alkali metal elements and alkaline earth metal elements in the fission products are separated, it is also desirable to effectively use.

So far, various isotope separation methods of alkali metal elements and alkaline earth metal elements have been developed, but none has been put into practical use except lithium.

  In addition, the isotope separation of lithium on an industrial scale has been performed by the mercury amalgam method so far. However, since the mercury amalgam method uses a large amount of mercury, the burden on the environment is a problem.

In addition to this, studies have been made so far for isotopic separation of alkali metal and alkaline earth metal elements using a cation exchanger such as an organic ion exchange resin. However, isotope separation using a cation exchange resin has a small separation coefficient, requires a very long time for separation, and the separation apparatus becomes large. In addition, zeolite of an inorganic ion exchanger has a relatively large separation coefficient, but has a problem that the ion exchange rate is extremely slow and practically cannot be used for industrial purposes.

On the other hand, studies on isotope separation using cyclic compounds such as crown ethers and cryptands are performed by chromatography using solvent extraction or resination. Isotope separation using cyclic compounds is known to have a large separation factor, but the solvent extraction method requires many steps to be repeated, making the device too large and complicated. It is said. Also known is an isotope separation method in which a cyclic compound is used as a resin, but since the exchange rate of isotopes is slow, the height is increased by one step, resulting in the enlargement of the entire apparatus and separation. The time required for this is extremely long.
JAERI JAERI-M Report JAERI-M 89-176

  That is, an object of the present invention is to provide an isotope separation method, an isotope separation apparatus, and an isotope separation means that have a low environmental impact and do not cause problems such as generation of a large amount of waste mercury. And

  Furthermore, another object of the present invention is that the separation factor is larger than that of an isotope separation method using a cation exchange resin, compared with an isotope separation method using an inorganic ion exchanger or a conventional cyclic compound resin. The present invention provides an isotope separation method, an isotope separation apparatus, and an isotope separation means that enable high-speed isotope exchange speed, miniaturization of the apparatus and system, easy operation, and separation in a short time. With the goal.

The present invention has been made in view of the above-mentioned problems of the prior art, and as a result of intensive studies, the present inventors have conducted an isotope exchange reaction in an isotope separation method using a resin containing a cyclic compound. Is not due to the slow isotope exchange rate between the cyclic compound and the alkali metal isotope or alkaline earth metal isotope, but there is a problem with the main chain resin that binds the cyclic compound And the present invention has been achieved.

That is, the conventional resin that forms the main chain structure has low hydrophilicity, and the cyclic compound having the main function of separating mainly has an ether bond and a methylene bond. For this reason, conventional resins pendant with cyclic compounds have lower hydrophilicity than other resins containing ion exchange groups, and as a result, aqueous solutions are less likely to penetrate into the main chain resin, leading to trap sites for cyclic compounds. The alkali metal element isotope or alkaline earth metal element does not diffuse efficiently in the main chain resin, and the efficiency of the action of the cyclic compound and the alkali metal element or alkaline earth metal element is lowered. I found. That is, the present invention has been completed by finding that it is possible to increase the isotope exchange rate by increasing the hydrophilicity of the main chain skeleton of the resin, and thus to reduce the height of the step in the chromatography. Is.

In the present invention, a polar functional group is bonded to the resin in order to increase the hydrophilicity of the resin. As a functional group having polarity, a cation exchange group and an anion exchange group are known. However, in the present invention, an alkali metal element and an alkaline earth metal element interact with an anion exchange group. Absent. Therefore, by bonding an anion exchange group to the resin, it is possible to impart hydrophilicity to the main chain skeleton of the resin without affecting the separation characteristics of the cyclic compound. That is, the present invention is isotope exchange efficiency between isotopes in solution an alkali metal element or an alkaline earth metal element isotopes of cyclic compounds obtained by pendant resin and complexing alkaline metal element or an alkaline earth metal element Is increased by adding an anion exchange group to the resin to increase the hydrophilicity of the resin.

  Furthermore, the present invention provides an isotope separation apparatus using a resin in which a cyclic compound is used as a functional group and pendant to the main chain skeleton, and an isotope separation means using the above-described resin.

That is, according to the present invention, a step of passing an alkali metal element or alkaline earth metal element solution through a separation column packed with a resin containing a cyclic compound functional group and an anion exchange group;
Separating the predetermined adsorption region of the solution using chromatography, and providing an isotope separation method. In the present invention, the cyclic compound functional group includes a crown ether or a cryptand. The resin of the present invention is a phenol resin, urea resin, melamine resin, xylene resin, toluene resin, guanamine resin produced from formaldehyde and a compound selected from the group comprising phenol, cresol, xylenol, or a mixture thereof. Or these copolymers can be selected from polystyrene, polyvinylphenol, styrene-acrylic polymer, styrene-vinyl copolymer, or a mixture thereof. The predetermined adsorption region of the present invention is a front end portion of an adsorption zone, and the separating step may include a step of separating a high-mass isotope among isotopes.

  According to the 2nd structure of this invention, an isotope separation apparatus provided with the isolation | separation means containing the porous particle which carry | supported the resin containing a cyclic compound functional group and an anion exchange group can be provided. The separation means is a separation column packed with the porous particles. The resin is a phenol resin, urea resin, melamine resin, xylene resin, toluene resin, guanamine resin, or these produced from a compound selected from the group comprising phenol, cresol, xylenol, or a mixture thereof and formaldehyde Resins selected from copolymers, polystyrene, polyvinylphenol, styrene-acrylic polymers, styrene-vinyl copolymers, or mixtures thereof can be included.

  According to the 3rd structure of this invention, the isotope separation means containing the porous particle | grains which carry | supported the resin containing a cyclic compound functional group and an anion exchange group can be provided. The separation means may be a separation column containing the porous particles.

That is, according to the present invention, it is possible to reduce the separation height in one stage, downsize the apparatus necessary for the isotope separation process, and shorten the time required for separation / concentration. It is possible to provide an isotope separation method, an isotope separation apparatus, and an isotope separation means that enable separation of alkali metal element and alkaline earth metal element isotopes at a level.

Furthermore, the present invention makes it possible to separate an alkali metal element and an alkaline earth metal element isotope by chromatography using a resin that is a stationary phase, without using mercury in the separation, and generating no mercury waste. It is possible to provide an isotope separation method, an isotope separation apparatus, and an isotope separation means with a low environmental load.

  The present invention will be described below with reference to embodiments shown in the drawings, but the present invention is not limited to the embodiments described below. FIG. 1 shows a schematic diagram of an isotope separation apparatus 10 of the present invention. The isotope separation device 10 shown in FIG. 1 is generally discharged from a supply tank 12 for storing a supply liquid containing an isotope to be concentrated, a separation column 14 used as an isotope separation means, and a separation column 14. And a collection tank 16 for accumulating a concentrated liquid enriched with a specific isotope. As shown in FIG. 1, the isotope separation device 10 of the present invention includes a pump 18 for supplying a supply liquid from a supply tank 12 to a separation column 14, and a flow path for the supply liquid from the pump 18. And a valve 20 for changing the flow rate and adjusting the flow rate.

The supply liquid stored in the supply tank 12 is an alkali metal element or alkaline earth metal element, water, or a mixed solution of water and a suitable organic solvent miscible with water or a mineral acid such as hydrochloric acid, sulfuric acid, nitric acid. Has been adjusted as. The pump 18 can be constituted by a quantitative pump or a constant pressure pump as long as the supply liquid can be supplied to the separation column 14. The liquid feeding system can be any diaphragm type, rotary blade type, etc. It can also be used with a liquid feed pump. The valve 20 controls the supply of the supply liquid to the separation column 14 and is arranged for selecting a separation method. The valve 20 can be an on / off valve and has a flow rate adjusting function. It can be a flow control valve.

  Furthermore, each of these devices or means is connected by a line 22, and in the first embodiment of the isotope separation method of the present invention, the supply liquid is flowed in one pass to perform isotope separation. Further, in the second embodiment of the isotope separation method of the present invention, a certain amount of the supply liquid can be circulated in the separation column 14 in order to increase the separation efficiency of the separation column 14. In the second embodiment of the isotope separation method of the present invention, first, the switching valve 24 is switched to the circulation line 26 so that the feed liquid flows, and at the same time, the feed liquid flows to the separation column 14 side. By switching in this way, the supply liquid is circulated.

  In the embodiment shown in FIG. 1, a plurality of, more specifically, five separation columns 14 are arranged in series in a series connection. In the first embodiment of the isotope separation method of the present invention, the feed liquid is concentrated in the first stage separation column, then sent to the second stage column, where it is further concentrated, and then sequentially. Concentrate while moving to the last column. A predetermined region of the feed liquid discharged from the final-stage separation column 14 and having an increased abundance ratio of a predetermined isotope is sent to the recovery tank 16 and accumulated therein. In certain embodiments, the accumulated solution is enriched with high mass isotopes of isotopes. In the second embodiment of the present invention, the isotope separation is performed by supplying a region enriched with a specific isotope to the separation column 14 and circulating it.

Concentrate is isotope abundance ratio of the final object, precipitation or using a suitable method such as distillation, recovered as the alkali metal element or an alkaline earth metal element was elevated isotope abundance Is done. In addition, the separation column 14 that can be used in the present invention can be used singly, or a plurality of separation columns 14 are arranged in series, in parallel, or in direct / parallel combined arrangement. It can be used appropriately depending on the efficiency, and the processing capacity can be appropriately designed in the range of several cm ³ / hr to several tens of M ³ / day. The separation means used in the present invention can be configured as a separation column 14 and can also be configured as an embodiment of a separation membrane in which porous particles described later are dispersed or supported.

  The separation column 14 shown in FIG. 1 is a hollow cylinder in a specific embodiment, and silica, alumina, kaolin, silica having a particle size of about 50 μm that functions as a stationary phase is disposed inside the separation column 14. Porous particles 28 such as acid glass are filled. The porous particle 28 further has pores of 100 nm to 1000 nm, gives a high contact area to the mobile phase, and further has a structure in which the cyclic compound used in the present invention is bonded to the main chain. A resin compound is supported. In a preferred embodiment of the present invention, the resin compound that can be used in the present invention can have a chemical structure in which a cyclic compound such as crown ether or cryptand is pendant on a resin having anion exchange properties.

  Specific examples of the crown ether derivative compound that can be used in the present invention include a crown ether derivative compound having a structure in which two hydrogen atoms of the crown ether are substituted with an arylene group. Examples of the arylene group bonded to the crown ether in the present invention include a phenylene group, a naphthylene group, an anthrylene group, and a pyrenylene group. Examples of the crown ether include 14-crown-4, 15-crown-5, 18-crown-6, 21-crown-7, 24-crown-4 and the like. More specifically, as the above-mentioned crown ether-arylene group derivative compound, benzo 14-crown-4, benzo 15-crown-5, naphtho 15-crown-5, benzo 18-crown-6, dibenzo 18-crown- 6, benzo 21-crown-7, benzo 24-crown-4, and the like.

  Examples of the resin that provides a main chain skeleton that can be used in the present invention include phenol, cresol, xylenol, pyridine, pyrimidine, triazine, or heterocyclic compounds containing these alkyl groups, aryl group-substituted derivatives, and the like, and formaldehyde or hexamethylene. Examples thereof include phenol resins produced from alkylene polyamine compounds such as tetramine. Besides phenol resins, urea resins, melamine resins, xylene resins, toluene resins, guanamine resins, copolymers thereof, or mixtures thereof are also included. Can be mentioned. In particular, in a preferred embodiment of the present invention, a resin skeleton imparted with anion exchangeability and affinity using hexamethylenetetramine as a methylol group and an aminomethyl group can be used as the main chain structure. In addition, in the present invention, as the anion exchange group, a functional group including a primary amine group, a secondary amine group, and a tertiary amine group can be used.

  As the resin of the present invention, compounds described in detail in Japanese Patent Application No. 2003-428314 filed by the present inventors can be used. Further, in the present invention, the above-described resin can be produced using conventionally known addition polymerization. For example, Otsu et al., “Experimental Method for Polymer Synthesis”, 10th printing, July 1986. On the 10th, it can be produced by the addition polymerization described in Kagaku Dojin Co., Ltd., issue. The pendant of arylene-modified crown ether can be made pendant by mixing a predetermined amount of a predetermined arylene-modified crown ether and synthesizing the arylene-modified crown ether to the main chain methylol group in the synthesis of a phenol resin or the like. Can do. In addition, in the synthesis | combination of resin, ammonia and another amine compound other than hexamethylenetetramine can be used as an additive. The molecular weight of the resin compound that can be used in the present invention is not particularly limited, but a weight average molecular weight of several thousand to 100,000 is preferable from the viewpoint of solubility and handleability.

  In the present invention, when a phenol / novolak-based resin is produced from a phenol derivative and hexamethylenetetramine, and a crown ether and an anion exchange group are introduced into the main chain skeleton, the resin can be produced according to the following polymerization method. it can. First, a crown ether derivative and a phenol derivative, preferably benzocrown and phenol, are dissolved in a halogenated carboxylic acid, preferably trichloroacetic acid or tetrafluoropropionic acid. Preferably, it dissolves by heating to 40 ° C to 120 ° C. The molar ratio of the benzocrown derivative and the phenol derivative can be 0.01 to 1, preferably 0.1 to 0.8. To this reactant solution, hexamethylenetetramine is dissolved by adding 0.01 to 10 times, preferably 0.1 to 1 times the total number of moles of the benzocrown derivative and the phenol derivative. The resulting solution is then heated at 160 ° C., preferably 60 ° C. to 140 ° C., more preferably 80 ° C. to 130 ° C., for 10 minutes to 1 month, preferably 1 hour to 2 weeks, more preferably 3 hours. To complete the polymerization reaction.

  More specifically, the resin compound that can be used in the present invention is given by the following general formula (1).

In the above formula, R ¹ and R ² may be the same or different and each represents a hydrogen atom, a methyl group, or an ethyl group. Represents a propyl group, a butyl group, or a halogen element, and R ³ represents a heterocyclic amine group such as an amide group, a secondary amine group, a tertiary amine group, a tertiary amine group, a third pyridine group, or a fourth pyridine group. And m and n are positive real numbers that satisfy the relationship m + n = 1.

In the present invention, the methylol group bonded to the phenyl group does not necessarily need to be converted to 100% aminomethyl group. In that case, the structure of the resin compound of the present invention is represented by the following general formula (2). Given in. At this time, in the following general formula (2), R ¹ and R ² may be the same or different and each represents a hydrogen atom, a methyl group, or an ethyl group. Represents a propyl group, a butyl group, or a halogen element, and R ³ represents a heterocyclic amine group such as an amide group, a secondary amine group, a tertiary amine group, a tertiary amine group, a third pyridine group, or a fourth pyridine group. M, n, and l are positive real numbers that satisfy the relationship of m + n + l = 1.

  Moreover, in order to provide anion exchange property in the main chain skeleton in the present invention, it has the following general formula (3) given by addition polymerization under acidic conditions using a phenol compound, pyridine and formaldehyde. Resin compounds can be used.

上記一般式（３）中、Ｒ^１、Ｒ^２、Ｒ^４は、同一でも異なっていてもよい、水素原子、メチル基、エチル基。プロピル基、ブチル基、ハロゲン元素を表し、Ｒ^３は、アミド基、第２アミン基、第３アミン基、第３アミン基、第３ピリジン基、または第４ピリジン基などの複素環式アミン基から選択される含窒素基であり、ｊ、ｋは、ｊ＋ｋ＝１の関係を満たす正の実数を意味する。

In said general formula (3), R < ¹ >, R < ² >, R < ⁴ > may be the same or different, and is a hydrogen atom, a methyl group, and an ethyl group. Represents a propyl group, a butyl group, or a halogen element, and R ³ represents a heterocyclic amine group such as an amide group, a secondary amine group, a tertiary amine group, a tertiary amine group, a third pyridine group, or a fourth pyridine group. Wherein j and k are positive real numbers that satisfy the relationship j + k = 1.

  In addition to the above-described compounds, for example, a single-chain compound having an unsaturated bond is polymerized to first form a main chain skeleton. On the other hand, formaldehyde and an arylene-modified crown ether are reacted to form a crown ether and A resin having an anion exchange group can also be produced. As a monomer for producing the above-described polymer, for example, a vinyl compound, an acrylic compound, or a methacrylic compound can be used. Specific examples of the acrylic compound or methacrylic compound include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, isopropyl acrylate, propyl methacrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate. , Acrylonitrile, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxybutyl (meth) acrylate, pentanediol mono (meth) acrylate, hexa Diol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acryloyl phosphate Examples thereof include fete, 4-hydroxycyclohexyl (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol tri (meth) acrylate, alkyl glycidyl ether, allyl glycidyl ether, acrylamide, and methacrylamide.

  Furthermore, examples of the polymerizable monomer that can be used in the present invention include trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, bentaerythritol tri (meth) acrylate, and bentaerythritol. Tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris (acryloyloxy) isocyanurate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (hydroxypropyl) isocyanurate tri (meth) Evening) Examples include acrylate, triallyl trimellitic acid, triallyl isocyanurate and the like. These ethylenically unsaturated compounds can be used alone or in combination of two or more.

  As the polymerizable monomer, a vinyl compound can also be used. Styrene, alkyl group-substituted styrene, alkoxy-substituted styrene, N-vinyl-nitrogen-containing heterocyclic compound such as vinyl pyridine, N-vinyl pyrrolidone, N-vinyl Caprolactam, N-vinylformamide, (meth) acrylate having a bridged alicyclic hydrocarbon group, for example, isobornyl (meth) acrylate, dicyclopentadiene (meth) acrylate, isobornyloxyethyl (meth) acrylate, dicyclo A monofunctional compound such as bentel (meth) acrylate can be used. The above-mentioned polymerization birth weight polymer is appropriately used in any mixing ratio and can be a copolymer. For example, when an arylene-modified crown ether and an anion exchange group are bonded to polyvinylphenol, a condensation reaction using formaldehyde, hexamethylenetetramine, etc. can be used. Adjustment can be made so that a resin having predetermined physical properties can be obtained.

  In the present invention, the aforementioned loading of the resin on the porous particles can be carried in situ by introducing the porous particles into the reaction vessel during the polymerization of the resin. In addition, when the resin compound is supported on the porous particles in the present invention, after the resin is manufactured, the resin is dissolved in an appropriate solvent capable of dissolving the manufactured resin, and hydrochloric acid is added to improve the adhesion. After adding an inorganic acid such as nitric acid or sulfuric acid to the resin solution, the porous particles are added to and stirred in the resin solution, impregnated with the resin solution, and dried. In the present invention, when the resin compound is supported on the porous particles, either of the two methods described above can be selected to suit a specific application and purpose, but depending on the properties of the resin, it can be dissolved in a solvent. Considering that the properties are greatly different, the method of supporting the resin compound on the porous particles during the polymerization has a broader compatibility and can provide a separation column with better characteristics.

  As the above-mentioned solvents, amyl alcohol, allyl alcohol, isoamyl alcohol, isobutyl alcohol, isopropyl alcohol, undecanol, ethanol, 2-ethylbutanol, 2-ethylhexanol, 2-octanol, n-octanol, glycidol, cyclohexanol, 3, 5, -dimethyl-1-hexyn-3-ol, n-decanol, tetrahydrofurfuryl alcohol, α-terpineol, neopentyl alcohol, nonanol, fusel oil, butanol, furfuryl alcohol, propargyl alcohol, propanol, hexanol, heptanol Benzyl alcohol, pentanol, methanol, methylcyclohexanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 3-methyl -1-butyn-3-ol, 4-methyl-2-pentanol, 3-methyl-1-pentyn-3-alcohols such ol can also be mentioned.

  Examples of the solvent further include anisole, ethyl isoamyl ether, ethyl t-butyl ether, ethyl benzyl ether, epoxy butane, crown ethers, cresyl methyl ether, diisoamyl ether, diisopropyl ether, diethyl acetal, diethyl ether, dioxane, 1 , 8-cineol, diphenyl ether, dibutyl ether, dipropyl ether, dibenzyl ether, dimethyl ether, tetrahydropyran, tetrahydrofuran, trioxane, bis (2-chloroethyl) ether, phenetol, butylphenyl ether, furan, furfural, methylal, methyl-t -Ether / acetal solvents such as butyl ether, methyl furan and monochlorodiethyl ether can also be mentioned. .

  Furthermore, as the solvent, acetylacetone, acetaldehyde, acetophenone, acetone, isophorone, ethyl-n-butylketone, diacetone alcohol, diisobutylketone, diisopropylketone, diethylketone, cyclohexanone, di-n-propylketone, phorone, mesityloxide, Similarly, ketone-aldehyde solvents such as methyl-n-amyl ketone, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanone, methyl-n-butyl ketone, methyl-n-propyl ketone, methyl-n-hexyl ketone and methyl-n-heptyl ketone Can be used.

  Furthermore, as the above-mentioned solvent, ethylene glycol, ethylene glycol dibutyl ether, ethylene glycol diacetate, ethylene glycol dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, Ethylene glycol monoethyl ether acetate, ethylene glycol monophenyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monomethoxymethyl ether , Ethylene chlorohi Phosphorus, 1,3-octylene glycol, glycerol, glycerol 1,3-diacetate, glycerol dialkyl ether, glycerol fatty acid ester, glycerol triacetate, glycerol trilaurate, glycerol monoacetate, 2-chloro-1,3- Mention may be made of polyhydric alcohols such as propanediol, 3-chloro-1,2-propanediol, diethylene glycol, diethylene glycol ethyl methyl ether, polypropylene glycol and derivatives thereof.

  Further, as the above-mentioned solvent, isovaleric acid, isobutyric acid, itaconic acid, 2-ethylhexanoic acid, 2-ethylacetic acid, oleic acid, caprylic acid, caproic acid, formic acid, valeric acid, acetic acid, lactic acid, pivalic acid are appropriately used. Carboxylic acid derivatives such as propionic acid, and phenols such as ethylphenol, octylphenol, catechol, guaiacol, xylenol, p-cumylphenol, cresol, dodecylphenol, naphthol, nonylphenol, phenol, benzylphenol, p-methoxyethylphenol, Acetonitrile, acetone cyanohydrin, aniline, allylamine, amylamine, isoquinoline, isobutylamine, isopropanolamines, isopropylamine, imidazole, N-ethylethanolamine, 2- Tylhexylamine, N-ethylmorpholine, ethylenediamine, caprolactam, quinoline, chloroaniline, ethyl cyanoacetate, diamylamine, isobutylamine, diisopropylamine, diisopropylethylamine, diaethanolamine, N, N-diethylaniline, diethylamine, diethylbenzylamine, diethylenetriamine , Dioctylamine, cyclohexylamine, triethylamine, triamylamine, trioctylamine, triethanolamine, triethylamine, trioctylamine, tri-n-butylamine, tripropylamine, trimethylamine, toluidine, nitroanisole, picoline, piperazine, pyrazine, Pyridine, pyrrolidine, N-phenylmorpholine, morpholine, butylamine Nitrogen-containing compounds such as heptylamine and lutidine, acid halides such as halogenated carboxylic acids such as trichloroacetic acid, sulfur-containing compound solvents, fluorine-based solvents such as tetrafluoropropionic acid, and the like. Any kind and addition amount can be mixed and used.

  The porous particles produced by the above-described method are packed in the separation column 14 to produce the separation column 14. Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples described below.

Production of resin compound, porous particles and separation column A resin having a cyclic compound and an anion exchange group was produced according to the following method. A mixture of benzo-15-crown-5 (5.22 g, 20 mmole), phenol (5.64 g, 60 mmole), and hexamethylenetetramine (3.50 g, 25.0 mmole), trichloroacetic acid (64 g, 3.92 mole). The mixture was mixed in a reaction vessel, and the mixture was dissolved under heating and reflux. Thereafter, porous silica (60 g, 150 ml, particle size 50 μm) was added to the reaction vessel, and the mixture was further heated and stirred for 49 hours while refluxing at 90 ° C., and further heated at 125 ° C. for 69 hours to obtain a resin compound. Was produced and supported on porous particles. The produced porous particles carrying the resin compound are washed several times with methanol and a 10% methanolic hydrochloric acid solution to obtain a resin compound of the following structural formula (4) having benzo-15-crown-5 and aminomethyl groups. As a result, 70 g of porous particles carrying s were obtained. At this time, the organic polymer carried on the porous particles was about 10.0 g.

また、陰イオン交換基は、重合途中に生成するメチロール基の水酸基をアミド基で置換したアミノメチル基とした。上記構造式（４）中、ｐは、正の整数である。

The anion exchange group was an aminomethyl group in which the hydroxyl group of the methylol group generated during the polymerization was substituted with an amide group. In the structural formula (4), p is a positive integer.

  Silica particles carrying the produced resin compound were packed into a column having an inner diameter of 8 mm and a length of 1 m to produce a separation column. Similarly, four separation columns were produced, and a total of five separation columns were produced.

O Separation operation A feed solution for separation was obtained by dissolving natural isotope abundance Li in a hydrochloric acid / methanol mixed solution as an aqueous solution of about 0.8 mol / dm ³ . Created. 5 manufactured separation columns are arranged in 5 stages in series, and the manufactured supply liquid is fed at a flow rate of 6 cm ³ / hr using a metering pump NP-KX-110U (manufactured by Seimitsu Chemical Co., Ltd.). Then, an isotope separation operation using a chromatographic method was performed.

  The eluent discharged from the separation column was analyzed for Li concentration using an atomic absorption analyzer (manufactured by Daini Seikosha, SAS / 727), and a surface ionization mass spectrometer (manufactured by Finigan Co., Ltd.) Analysis of Li isotope ratio was performed using MAT261).

Results FIG. 2 shows the elution characteristics of Li from the separation column obtained by the present invention. In FIG. 2, the vertical axis represents the Li concentration mol / dm ³ and the horizontal axis represents the amount of eluent / cm ³ . In FIG. 2, the Li concentration starts to increase when Li reaches the detection unit, and then reaches a steady state with a constant concentration. FIG. 3 shows a graph in which isotope enrichment characteristics are plotted against the amount of Li eluent. There are two types of Li, ⁶ Li and ⁷ Li, as stable isotopes, and as shown in FIG. 3, ⁷ Li is higher in elution, so that ⁷ Li is concentrated at the front end of the adsorption band. Indicated. Therefore, it was shown that in Li isotope separation, ⁷ Li isotope separation can be performed by separating the front end of the adsorption zone.

The isotope separation of the alkaline earth metal element Sr was performed using the isotope separation apparatus of Example 1 except that only one separation column manufactured in Example 1 was used. The Sr solution was a 9 mol / dm ³ hydrochloric acid solution, and the analysis of the Sr concentration and isotope ratio was performed using an inductively coupled plasma mass spectrometer (X7, manufactured by Jarrell Ash Co., Ltd.).

FIG. 4 shows the elution characteristics of Sr, and FIG. 5 shows the isotope enrichment characteristics. As shown in FIG. 4 and FIG. 5, it is shown that ⁸⁸ Sr is also concentrated at the front end of the adsorbent in Sr. In FIG. 5, bars attached to the top and bottom of the measurement point indicate standard errors, and it is apparent that ⁸⁸ Sr is clearly concentrated at the front end. Further, as shown in FIG. 5, it was shown that ⁸⁸ Sr can be concentrated and separated also in Example 2 by separating the front end portion of the adsorption zone.

1 is a schematic diagram of an isotope separation apparatus of the present invention. The figure which showed the Li elution characteristic from the separation column of this invention. The figure which showed the Li isotope enrichment characteristic by the separation column of this invention. The figure which showed the Sr elution characteristic from the separation column of this invention. The figure which showed the Sr isotope enrichment characteristic by the separation column of this invention.

DESCRIPTION OF SYMBOLS 10 ... Isotope separation apparatus 12 ... Supply tank 14 ... Separation column 16 ... Recovery tank 18 ... Pump 20 ... Valve 22 ... Line 24 ... Switching valve 26 ... Circulation line 28 ... Porous particle

Claims (6)

A separation column that porous silica was filled with a resin carrying containing a crown ether derivative group and an anion-exchange groups, a step leading to a solution of an alkali metal element or an alkaline earth metal element,
Separating the predetermined adsorption region of the solution using chromatography.   The resin is a phenol resin, urea resin, melamine resin, xylene resin, toluene resin, guanamine resin, or these produced from a compound selected from the group comprising phenol, cresol, xylenol, or a mixture thereof and formaldehyde The isotope separation method according to claim 1, comprising a resin selected from a copolymer, polystyrene, polyvinylphenol, styrene-acrylic polymer, styrene-vinyl copolymer, or a mixture thereof. The predetermined adsorption region is a front end portion of an eluent containing an isotope after adsorption, and the separating step includes a step of increasing an isotope abundance ratio of high-mass isotopes in the eluent among the isotopes. The isotope separation method according to claim 1 or 2. An isotope separation apparatus for alkali metal elements and alkaline earth metal elements , which is a separation column packed with porous particles carrying a resin containing a crown ether derivative group and an anion exchange group. The resin may be a phenol resin, urea resin, melamine resin, xylene resin, toluene resin, guanamine resin, or these produced from a compound selected from the group comprising phenol, cresol, xylenol, or a mixture thereof and formaldehyde The isotope separation device according to claim 4, comprising a resin selected from a copolymer, polystyrene, polyvinylphenol, styrene-acrylic polymer, styrene-vinyl copolymer, or a mixture thereof. An isotope separation column for alkali metal elements and alkaline earth metal elements packed with porous particles carrying a resin containing a crown ether derivative group and an anion exchange group.

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