JP2006272193A - Method and apparatus for separating zinc isotope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and economical separation method capable of surely absorbing a predetermined zinc isotope to be removed, and to provide an apparatus therefor. <P>SOLUTION: An acidic solvent, in which a zinc salt containing zinc isotope is dissolved, is passed through a column filled with an organic polymer of a resorcinol derivative having a crown ether structure as a functional group at side chains, which is synthesized by adding and dissolving the resorcinol derivative, benzocrown ether and paraformaldehyde or formaldehyde in halogen-containing fatty acid and reacting them for a predetermined time at a predetermined temperature, and is carried on a porous silica carrier, or the organic polymer itself made into a porous body, and then the zinc isotope is absorbed with the organic polymer by means of a chromatography. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for separating zinc ion isotopes using an organic polymer of a resorcinol derivative having a crown ether structure. More specifically, the present invention relates to a method and an apparatus for separating a zinc ion isotope by chromatography using a difference in adsorption characteristics between a zinc ion isotope and an organic polymer.

  The radioactive cobalt that elutes into the light water reactor cooling water is the biggest cause of radiation exposure accidents for reactor workers, and suppressing the dissolution of radioactive cobalt into the light water reactor cooling water not only ensures the safety of the reactor workers. In addition, ensuring the safety of reactor workers will contribute to the stable operation of nuclear power plants.

  As a means for suppressing elution of radioactive cobalt into the light water reactor cooling water, there is a method of injecting zinc into the light water reactor cooling water. However, zinc-64 contained in natural zinc is changed to zinc-65 having a radioactivity with a half-life of 243.8 years after activation in light water reactor cooling water. For this reason, it is necessary to inject zinc in which zinc-64 is impaired (hereinafter referred to as “impaired zinc”). Currently, this zinc is imported from the US company, which was produced by a centrifuge developed for uranium enrichment.

  By the way, the centrifuge for enriching uranium in Japan is specialized for enriching uranium and is not suitable for other elements.

  On the other hand, a method using a crown ether derivative extractant is known for separating zinc ion isotopes. There are examples of large separation factor values reported for the target zinc isotopes, but they are not reproducible. Furthermore, the extraction separation is complicated and the practical use is very difficult, and an extra operation for removing the crown ether derivative mixed in the separated zinc ion isotope occurs, and the separation operation is difficult. There are also circumstances.

  If the crown ether can be converted into a resin in order to facilitate the separation operation, there is a possibility that a versatile separation medium can be formed as if it is an ion exchange resin. Regarding resination of crown ether, there are those in which a crown ether derivative is impregnated in an organic polymer, but there is still no polymerized polymer. There are reports of binding crown ether derivatives to organic polymers, but synthesis of crown ether derivatives bound to organic polymers is very difficult and expensive, and is not suitable for general separation methods such as industrial separation. It is. Furthermore, there is no reliable report that binds a crown ether derivative to a resorcinol-formaldehyde resin that is inexpensive and has an affinity for hydrogen polar solvents such as water, lower alcohol, and lower fatty acid.

  For example, there has been a report by Noni et al. Regarding the separation of metal ion isotopes (Non-Patent Document 1). Regarding the method for producing a resin having a crown ether derivative, the structure and properties of the crown ether derivative compound, and the separation of the metal ion isotope No detailed report has been made.

  It is very difficult to make crown ether derivatives insoluble polymers in polar solvents, and it is also very difficult to make crown ether derivatives stable organic polymers. There are no crown ether derivative resorcinol and formaldehyde resins that adsorb well.

  The applicants of the present application filed an invention for the purpose of providing a method capable of separating an inexpensive zinc isotope with a simple apparatus, and this invention is disclosed in Japanese Patent Application Laid-Open No. 2001-70757. The technique disclosed in Japanese Patent Application Laid-Open No. 2001-70757 is a solution to this problem. A solution containing a zinc isotope is passed through a column packed with a crown ether resin, and zinc is adsorbed on the crown ether resin to form a zinc adsorption zone. After formation, the eluent is passed through the column to obtain a concentrated zinc isotope.

However, the crown ether resin used in the technique disclosed in Japanese Patent Application Laid-Open No. 2001-70757 is deteriorated by a polar hydrogen solvent. Sex is not enough.
Yasutoshi BAN, Masao NOMURA and Yasuhiko FUJII, Journal of Nuclear Science and Technology, Vol.39, No.2, pp.156-159, February 2002 JP 2001-70757 A

  Based on the above circumstances, the present invention is a simple and economical zinc isotope capable of reliably adsorbing a target zinc isotope, and capable of withstanding repeated use. It aims at providing the separation method with a separation device.

また、本願請求項２に係る亜鉛同位体の分離方法は、前記含ハロゲン脂肪酸中に、下記一般式（３）で示される１種類以上のレゾルシノール誘導体（式中ｍは０から９の整数であり、ｒは１ないし５であり、ｓおよびｔは０または１、R４およびR５は水素、炭素数が１から６個であるアルキル基、塩素、または臭素）の混合物と、前記一般式（２）で示されるベンゾクラウンエーテル（式中ｋは２，３，４，５，６）と、パラホルムアルデヒドまたはホルムアルデヒドと、を混合し、２０℃ないし１５０℃下で１分ないし３６時間反応させて合成されるクラウンエーテル構造を官能基として側鎖に有するレゾルシノール誘導体の有機高分子を、多孔質シリカ担体もしくは溶液中で化学変化しない物質で作られた多孔質担体中に担持させたもの、または前記有機高分子自身を多孔質体としたものを充填したカラムに、亜鉛同位体を含む亜鉛塩が溶解された酸性の有機溶剤を通液し、クロマトグラフィーにより前記亜鉛同位体を前記レゾルシノール誘導体の有機高分子に吸着させることを特徴としている。

そして、本願請求項３に係る亜鉛同位体の分離方法は、請求項１または請求項２に記載の亜鉛同位体の分離方法であり、前記含ハロゲン脂肪酸はトリクロロ酢酸であって、モル数１の前記一般式（２）で示されるベンゾクラウンエーテルに対して、前記一般式（１）または前記一般式（３）で示されるレゾルシノール誘導体のモル数の合計は０．１ないし１０であることを特徴としている。
さらに、本願請求項４に係る亜鉛同位体の分離方法は、請求項１、請求項２、または請求項３に記載の亜鉛同位体の分離方法であって、前記ベンゾクラウンエーテルは前記一般式（２）で示される式中のｋが３または４であることを特徴としている。
また、本願請求項５に係る亜鉛同位分離装置は、請求項１、請求項２、請求項３、または請求項４のいずれかに記載の亜鉛同位体の分離方法に使用する分離装置であって、１つ以上の前記カラムを直列および／または並列に接続したことを特徴としている。 In order to solve the above-mentioned problems, a method for separating zinc isotopes according to claim 1 of the present invention includes the following general formula (1) in a halogen-containing fatty acid (2 to 4 carbon atoms, and halogen is fluorine or chlorine). One or more resorcinol derivatives represented by (wherein j is an integer of 0 to 9, p and q are 0 or 1, R ₁ is an alkylene group having 2 to 10 carbon atoms, ₂ and R ₃ are a mixture of hydrogen, an alkyl group having 1 to 6 carbon atoms, chlorine, or bromine, and a benzocrown ether represented by the following general formula (2) (wherein k is 2, 3, 4) 5, 6) and paraformaldehyde or formaldehyde are mixed and reacted at 20 ° C. to 150 ° C. for 1 minute to 36 hours to synthesize resorcinol having a crown ether structure as a functional group in the side chain A column packed with a conductive organic polymer supported on a porous silica carrier or a porous carrier made of a substance that does not chemically change in a solution, or a porous material made of the organic polymer itself. In addition, an acidic organic solvent in which a zinc salt containing a zinc isotope is dissolved is passed, and the zinc isotope is adsorbed to the organic polymer of the resorcinol derivative by chromatography.

In addition, the method for separating zinc isotopes according to claim 2 of the present invention includes one or more resorcinol derivatives represented by the following general formula (3) in the halogen-containing fatty acid (wherein m is an integer of 0 to 9). , R is 1 to 5, s and t are 0 or 1, R4 and R5 are hydrogen, an alkyl group having 1 to 6 carbon atoms, chlorine, or bromine), and the above general formula (2) Benzocrown ether (wherein k is 2,3,4,5,6) and paraformaldehyde or formaldehyde are mixed and reacted at 20 ° C to 150 ° C for 1 minute to 36 hours. A resorcinol derivative organic polymer having a crown ether structure in the side chain as a functional group is supported on a porous silica carrier or a porous carrier made of a substance that does not change chemically in solution. Alternatively, an acidic organic solvent in which a zinc salt containing zinc isotope is dissolved is passed through a column packed with a porous body of the organic polymer itself, and the zinc isotope is converted to the resorcinol derivative by chromatography. It is characterized by being adsorbed on organic polymers.

A zinc isotope separation method according to claim 3 of the present application is the zinc isotope separation method according to claim 1 or claim 2, wherein the halogen-containing fatty acid is trichloroacetic acid, and the number of moles is 1. The total number of moles of the resorcinol derivative represented by the general formula (1) or the general formula (3) is 0.1 to 10 with respect to the benzocrown ether represented by the general formula (2). It is said.
Furthermore, the zinc isotope separation method according to claim 4 of the present application is the zinc isotope separation method according to claim 1, claim 2, or claim 3, wherein the benzocrown ether has the general formula ( In the formula shown in 2), k is 3 or 4.
A zinc isotope separation apparatus according to claim 5 of the present application is a separation apparatus used for the zinc isotope separation method according to any one of claims 1, 2, 3, or 4. One or more of the columns are connected in series and / or in parallel.

  The crown ether resin used in the invention according to claim 1 or claim 2 of the present application is obtained by condensing a crown ether and a resorcinol derivative using paraformaldehyde or formaldehyde to obtain a crown ether resin. By this synthesis method, a crown ether resin which is an organic polymer of a resorcinol derivative having a crown ether structure insoluble in a polar solvent can be obtained.

  Then, a crown ether resin insoluble in this polar solvent is supported on a porous silica carrier or a porous carrier made of a substance that does not chemically change in a solution, or the crown ether resin itself is a porous body. Zinc isotopes are separated by chromatography in a predetermined aqueous solution or an organic solvent using a column packed with the above. Therefore, an apparatus using this separation method can be a static and simple apparatus without requiring a dynamic and large-scale apparatus such as a centrifuge.

  The temperature of the halogen-containing fatty acid which is a liquid needs to be maintained at 20 ° C. to 150 ° C. and more preferably, in order to dissolve the crown ether derivative, resorcinol derivative and paraformaldehyde or formaldehyde and cause a covalent bond reaction. Is from 60 ° C to 140 ° C, more preferably from 80 ° C to 130 ° C. The reaction time is 1 minute to 36 hours, more preferably 1 hour to 24 hours.

  The halogen-containing fatty acid is more preferably trichloroacetic acid, but may be tetrafluoropropionic acid. In the invention according to claim 3 of the present application, the halogen-containing fatty acid is trichloroacetic acid for economic reasons. The molar ratio of the resorcinol derivative to the benzocrown ether is 0.5 to 4, and the molar ratio is more preferably 0.75 to 2.0.

  In the invention according to claim 4 of the present application, n of the benzocrown ether represented by the formula (2) is 3 or 4. As the number of n increases, the ring formed by the benzocrown ether increases, and the size of the metal ions adsorbed with it increases. Therefore, n can be appropriately selected depending on the metal ions to be adsorbed. By setting n to 3 or 4, zinc-64 can be adsorbed efficiently.

  In the invention according to claim 5 of the present application, one or more columns according to claim 1, claim 2, claim 3 or claim 4 are connected in series and / or in parallel. Therefore, as described in paragraph (0014), this apparatus is a static and simple apparatus, and by using a plurality of the columns, a compact zinc isotope separation apparatus with good adsorption efficiency. It can be. This separation apparatus is configured to pass a solution containing zinc isotope through the column, adsorb a predetermined zinc isotope on the crown ether resin packed in the column, and form a zinc adsorption zone. Then, the eluent is passed through to separate the concentrated predetermined zinc isotope.

  Embodiments 1 to 6 according to the best mode for carrying out the invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of an experimental separation apparatus for carrying out the present invention, and FIG. 2 is a graph of experimental data according to Example 1.

  First, before describing Examples 1 to 6, a method for producing a porous silica carrier carrying an organic polymer of a resorcinol derivative having a crown ether structure as a functional group in a side chain according to the present invention is used. Reference examples 1 and 2 will be described.

(Reference Example 1)
In a 1 dm ³ eggplant flask, 3,3′-pentamethylenedioxydiphenol (18.7 g, 65.0 mmol) and benzo-15-crown-5 (14.5 g, 54.0 mmol) were added to 140 g of trichloroacetic acid, Dissolve by heating to 90 ° C. with stirring. Paraformaldehyde (2.05 g, 68.3 mmol in terms of formaldehyde) is added little by little to this solution while stirring at 70 ° C. After the addition, the temperature is raised to 90 ° C. and heated for 2 hours. Next, after cooling to 60 ° C. or less, 120 g of silica (manufactured by Mizusawa Chemical Co., Ltd .: registered trade name “Sylbead”) is added and stirred with a stir bar to uniformly adsorb the entire solution onto the silica. Next, add the same amount (2.05 g) of paraformaldehyde, and stir again uniformly with a stir bar. The silica adsorbed with the solution in the eggplant flask is heated at 90 ° C. for 3 hours while being rotated and mixed by a rotary evaporator. After completion of the heating, the mixture is cooled to room temperature, and the final paraformaldehyde (4.1 g, 135.3 mmol in terms of formaldehyde) is added, and the mixture is uniformly mixed with a stirrer. After mixing, the reaction is completed by heating again at 90 ° C. for 2 hours and further at 110 ° C. for 4 hours on a rotary evaporator. After cooling to room temperature, 500 cm ³ of methanol is added to wash the silica. This washing is repeated about three times until the washing liquid is almost not colored. After completion of washing, the mixture is filtered and dried under reduced pressure at 60 ° C. for 12 hours to obtain 154.0 g of a crude silica-supported resin. The yield of only the organic component was 92%.
The crude resin is passed through a sieve of 100 mesh (0.154 mm), and the remainder is crushed lightly and passed. The operation of dispersing the resin passed through the sieve in 500 cm ³ of methanol and removing the fine silica-supported resin by a decantation method is repeated about 3 times. After filtration, drying is performed to obtain a crown ether resin which is a cocondensate of 3,3′-pentamethylenedioxydiphenol, benzo-15-crown-5, and paraformaldehyde supported on brown silica. The yield of this resin was 130 g.

(Reference Example 2)
3,3′-pentamethylenedioxydiphenol (18.7 g, 65.0 mmol) in Reference Example 1 was changed to 3,3′-ethylenedioxydiphenol (16.0 g, 65.0 mmol), and benzo-15 -Brown silica supported by reacting under the same conditions as in Reference Example 1 except that Crown-5 (14.5 g, 54.0 mmol) was changed to Benz-18-crown-6 (16.9 g, 54.0 mmol) To give a crown ether resin which is a cocondensate of 3,3'-ethylenedioxydiphenol, benzo-18-crown-6, and paraformaldehyde. The yield of this resin was 134 g.

  Examples 1 to 6 will be described below. First, an experimental separation apparatus for carrying out the present invention will be outlined with reference to FIG. In FIG. 1, reference numeral 10 is an experimental separator, reference numeral 12 is a column, reference numeral 14 is a raw material container, reference numeral 16 is a recovery container, reference numeral 18 is a switching valve for injection, reference numeral 20 is a switching valve for circulation, and reference numeral 22 is a first switching valve. The reference numeral 24 is a second liquid supply pump, the reference numeral 26 is an injection pipe, the reference numeral 30 is a discharge pipe, and the reference numeral 32 is a bypass pipe.

  The experimental separation apparatus 10 is roughly divided to connect the column 12, the injection switching valve 18 and the circulation switching valve 20, the first liquid feeding pump 22 and the second liquid feeding pump 24, and these devices. And piping. The column 12 is filled with silica carrying a predetermined crown ether resin according to the present invention, and forms a stationary phase in chromatography. The column 12 is a column with a water cooling jacket having a diameter of 0.8 cm and a length of 1 m.

  The injection pipe 26, the column 12, and the discharge pipe 30 are connected in this order to form a first liquid passage line, and the first liquid feed pump 22 and the intermediate part of the injection pipe 26 are arranged in order from the upstream side. An injection switching valve 18 is inserted, and a circulation switching valve 20 is inserted in an intermediate portion of the discharge pipe 30. A bypass pipe 32 connects the injection switching valve 18 and the circulation switching valve 20, and a second liquid feed pump 24 is inserted in an intermediate portion of the bypass pipe 32. For this reason, a part of the injection pipe 26, the column 12, a part of the discharge pipe 30 and the bypass pipe 32 form a second liquid passage that circulates through the column 12.

  The experiment according to the example was performed using the above-described first liquid passage. That is, the raw material container 14 containing a solution containing zinc is disposed at the tip of the injection pipe 26, and the injection switching valve 18 and the circulation switching valve 20 are opened and closed so that the first liquid passage pipe is opened. Then, the first liquid feed pump 22 is operated. As a result, the solution containing zinc in the raw material container 14 is sequentially injected from the injection pipe 26 to the column 12, discharged from the discharge pipe 30 through the column 12, and stored in the recovery container 16.

  While the zinc-containing solution flows down through the column 12, a predetermined zinc isotope is adsorbed by the adsorption characteristics of the predetermined crown ether resin packed in the column 12. Therefore, by comparing the mass distribution of the raw material container 14 and the mass distribution of the zinc isotope in the recovery container 16, the adsorption characteristics of the predetermined crown ether resin in the column 12 can be analyzed.

  In addition, the 2nd liquid flow path of the above-mentioned experimental separation apparatus 10 has an effect which raises the adsorption rate of a predetermined zinc isotope by circulating the solution containing zinc in the column 12. FIG. The second liquid passage line is used by opening and closing the injection switching valve 18 and the circulation switching valve 20 to open the second liquid passage line and operating the second liquid feed pump 24. However, it was not used in this experiment. In addition, although one column is used in the experimental separation apparatus 10, two or more columns may be used. Of course, in the case of two or more columns, the columns may be in series and / or in parallel. Of course there is. The basic components of the separation device on a commercial basis are substantially the same as those of the experimental separation device 10, and the difference is the size and scale of the separation device.

Then, the solvent of methanol hydrogen chloride concentration was hydrogen chloride to a concentration of 0.1 mol / dm ^3, the solution prepared by dissolving zinc chloride 0.1 mol / dm ^3, at room temperature (approximately 20 ° C.) In the column, the zinc isotope ratio was varied by flowing down the column 12 at a flow rate of 6 cm ^{3 /} h. The isotope ratio was measured with a quadrupole inductively coupled plasma mass spectrometer manufactured by Thermo electron.

FIG. 2 is a graph of experimental data according to Example 1. In FIG. 2, the horizontal axis represents the amount of eluent (unit: cm ³ ) and the vertical axis represents the zinc concentration value (value of zinc-68 relative to zinc-64). 6 is a graph showing how the zinc concentration value in the collection container 16 changes depending on the amount of eluent when 000 is set. The heavy zinc isotope zinc-68 is distributed in the solution, the light zinc isotope zinc-64 is distributed in the resin, and the zinc isotope eluted from the column is zinc-68, which is the peak value in Example 1. It can be seen that zinc-64 is effectively adsorbed on the crown ether resin having k = 3 in the general formula (2).

  In Examples 2 to 6, the above-mentioned crown ether resin was filled, and the experiment was performed by following the same procedure as in Example 1 with various solvents. The results are shown in Table 1. In each of Examples 2 to 6, as in Example 1, the solution containing zinc was divided into heavy zinc-68 in the solution and light zinc-64 in the crown ether resin. Heavy zinc-68 is concentrated. The tip value in the table indicates how much zinc-68 is concentrated from the original value with respect to zinc-64, and in each case, zinc-64 effectively relates to the present invention. It can be seen that it is adsorbed on the crown ether resin.

FIG. 1 is a schematic diagram of an experimental separation apparatus for carrying out the present invention. FIG. 2 is a graph of experimental data according to Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Separation apparatus for experiment 12 Column 14 Raw material container 16 Collection | recovery container 18 Switch valve 20 for injection 20 Switching valve 22 for circulation 22 1st liquid feed pump 24 2nd liquid feed pump 26 Injection pipe 30 Discharge piping 32 Bypass piping

Claims (5)

In halogen-containing fatty acids (2 to 4 carbon atoms, and halogens are fluorine and chlorine),
One or more resorcinol derivatives represented by the following general formula (1) (wherein j is an integer of 0 to 9, p and q are 0 or 1, and R ₁ has 2 to 10 carbon atoms) An alkylene group, R ₂ and R ₃ are a mixture of hydrogen, an alkyl group having 1 to 6 carbon atoms, chlorine, or bromine, and a benzocrown ether represented by the following general formula (2) (wherein k 2, 3, 4, 5, 6) and paraformaldehyde or formaldehyde are mixed and reacted at 20 ° C to 150 ° C for 1 minute to 36 hours. An organic polymer of a resorcinol derivative,
In a column packed with a porous silica carrier or a porous carrier made of a substance that does not chemically change in a solution, or a column packed with the organic polymer itself as a porous body,
Passing an acidic organic solvent in which a zinc salt containing a zinc isotope is dissolved,
A method for separating a zinc isotope, wherein the zinc isotope is adsorbed on an organic polymer of the resorcinol derivative by chromatography.

In the halogen-containing fatty acid, one or more resorcinol derivatives represented by the following general formula (3) (wherein m is an integer of 0 to 9, r is 1 to 5, s and t are 0 or 1) , R ₄ and R ₅ are a mixture of hydrogen, an alkyl group having 1 to 6 carbon atoms, chlorine or bromine, and a benzocrown ether represented by the general formula (2) (wherein k is 2, 3 , 4, 5, 6) and paraformaldehyde or formaldehyde and reacting at 20 ° C. to 150 ° C. for 1 minute to 36 hours to synthesize a resorcinol derivative having a crown ether structure as a functional group in the side chain The above organic polymer is supported on a porous silica carrier or a porous carrier made of a substance that does not chemically change in a solution, or the organic polymer itself is used as a porous body. To a column packed with,
Passing an acidic organic solvent in which a zinc salt containing a zinc isotope is dissolved,
A method for separating a zinc isotope, wherein the zinc isotope is adsorbed on an organic polymer of the resorcinol derivative by chromatography.

  The halogen-containing fatty acid is trichloroacetic acid, and the resorcinol derivative represented by the general formula (1) or the general formula (3) with respect to the benzocrown ether represented by the general formula (2) having 1 mole. The method for separating zinc isotopes according to claim 1 or 2, wherein the total number of moles is 0.1 to 10.   4. The method for separating zinc isotopes according to claim 1, wherein k in the formula represented by the general formula (2) is 3 or 4 in the benzocrown ether. 5. .   The zinc isotope used in the zinc isotope separation method according to claim 1, wherein the one or more columns are connected in series and / or in parallel. Body separation device.

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