JPH0460701B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anion exchange resin for enriching boron isotopes. More specifically, the present invention relates to an aminopolyol type anion exchange resin for boron isotope enrichment having specific physical properties. Boron naturally exists in a ratio of approximately 20% boron-10 (10B) and approximately 80% boron-11 (11B), of which 10B has excellent properties as an absorber for neutrons generated by nuclear reactions, etc. However, it is used as a neutron absorbing material in control rods, etc. in various nuclear reactors, and is an essential material in the nuclear power industry. However, as mentioned above, 10B has a natural abundance ratio of 20%, and the rest is 11B, which has almost no neutron absorption capacity. Therefore, in order to efficiently absorb and control neutrons in nuclear reactors, etc., 10B is necessary. It is necessary to separate and concentrate 10B from natural boron, which is an isotopic mixture of 11B. One known method for separating boron isotopes is to use multiple ion exchange towers filled with ion exchange resins and develop boric acid using ion exchange chromatography to enrich the boron isotopes. . Among them, styrene-based chelating anion exchange resins that have aminopolyols as functional groups that exhibit high selectivity for boric acid have _the following formula for the ^separation of boron isotopes: Molar concentration of 10B) / (Molar concentration of 11B in the ion exchange resin) / (Molar concentration of 10B in the solution) / (Molar concentration of 11B in the solution) ... The isotope separation coefficient ( a ¹⁰ ₁₁ ) is higher than that of other conventional strongly basic anion exchange resins and weakly basic anion exchange resins, making it an interesting resin (French Patent No. 1520521). These resins include Diaion CRB02 (manufactured and sold by Mitsubishi Chemical Industries, Ltd.), Amberlite IRA743 (manufactured and sold by Rohm and Haas, Inc. in the United States, product name,
It is commercially available under the former name XE243). However, these resins generally have a slow adsorption/desorption reaction rate for boric acid, and furthermore, at a boron isotope concentration, the isotope exchange reaction rate between 10B and 11B is slow, and the HETP (Height
The value of Equivalent of a Theoretical Plate (used as a measure to express the isotope exchange reaction rate) is large, and for this reason, enrichment of boron isotopes using the anion exchange resin cannot be said to be a particularly excellent method. HETP = (L ₂ − L ₁ ) log a ¹⁰ / ₁₁ / log R ₂ / R ₁ ... [] (However, R ₁ and R ₂ are the positions of the boron isotope enrichment zone
Isotope ratio of L ₁ and L ₂ ) The present inventor has discovered that when concentrating boron isotopes using a specific anion exchange resin, there is a correlation between the volume change rate of the HETP and the anion exchange resin. The present invention was completed based on the discovery that anion exchange resins having a specific swelling degree can be used efficiently for concentrating boron isotopes. That is, in the present invention, boric acid is passed through an ion exchange resin layer made of an aminopolyol type anion exchange resin to form a boric acid adsorption zone, and then an acid solution is passed through an ion exchange resin layer to concentrate boron isotopes. The anion exchange resin used is an anion exchange resin for boron isotope concentration, characterized in that it has a volume change rate of 8 to 30 expressed by the following formula: Volume change rate = V ₂ - V ₁ / V ₁ ×100 ...[] However, V ₁ : Volume of free amine type resin in water V ₂ : Volume of hydrochloric acid adsorption type resin in water. The anion exchange resin used in the present invention is produced by first producing a crosslinked polymer having a halomethyl group,
It is then produced by reacting this with a specific amine. A crosslinked copolymer having a halomethyl group is produced by dissolving a monovinyl aromatic monomer such as styrene and a polyvinyl aromatic monomer such as divinylbenzene by a known method. A solvent that swells. For example, copolymerization is carried out by adding benzene, toluene, xylene, chlorobenzene, carbon tetrachloride, tetrachloroethane, trichloroethylene, etc. in an amount of about 0 to 200% by weight based on the monomer, and the resulting gel-like or porous copolymer is A method of reacting the polymer with chloromethyl methyl ether, or after copolymerizing by adding an aromatic linear polymer such as polystyrene in an amount of about 0 to 50% by weight based on the total amount of monomers when copolymerizing the above monomers. ,
A method in which a gel-like or porous copolymer obtained by extracting and removing the linear polymer with a solvent is reacted with chloromethyl methyl ether, or
Solvents (precipitation solvents), such as n-
Polymerization is carried out by adding pentane, i-octane, n-heptane, etc. in an amount of about 0 to 120% by weight based on the total amount of monomers, and the resulting gel-like or porous copolymer is halomethylated by the method described above. manufactured by As the monovinyl aromatic monomer used in the above method, in addition to styrene, aromatic vinyl compounds such as vinyltoluene, ethylstyrene, vinylanisoate, and vinylnaphthalene are useful.
In addition to divinylbenzene, useful polyvinyl aromatic monomers include divinylethylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, divinyl ether, ethylene glycol dimethacrylate, ethylene glycol diacrylate, and divinyl ketone polyallyl ether. The amount used can range from 2 to 12% by weight based on the total monomers. For copolymerization, a polymerization catalyst such as benzoyl peroxide, lauroyl peroxide, or azobisisobutyronitrile is added in an amount of 0.1 to 10% by weight based on the monomer.
It is carried out by reacting for 6 to 20 hours at .degree. As the polymerization method, known methods such as suspension polymerization and bulk polymerization can be employed. Halomethylation of the aromatic crosslinked copolymer is carried out by a known method, for example, using chloromethyl methyl ether in the presence of a Friedel-Crafts catalyst such as zinc chloride and heating to 20-60°C. The amount of chloromethyl methyl ether can vary within a wide range per 100 g of aromatic crosslinked copolymer, but is preferably
A range of 80g to 500g can be mentioned. In addition to the method described above, the aromatic crosslinked polymer having halomethyl groups can be obtained by crosslinking copolymerization of a halomethylated aromatic monovinyl compound such as chloromethylstyrene and a polyvinyl compound such as divinylbenzene according to the method described above. It can also be produced by a method. The specific amine to be reacted with the crosslinked copolymer having a halomethyl group has the following general formula [] [However, in the formula, n represents an integer of 1 to 6,
R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or -CH ₂ [-CH(OH)] - _n CH ₂ OH (in the formula, m is 0,
(indicates an integer from 1 to 6)] Specifically, the above-mentioned specific amine includes N-
Glucamine, N-galactamine, N-mannosamine, N-arabitylamine, N-methyl-glucamine, N-ethyl-glucamine, N-methyl-galactamine, N-ethyl-galactamine, N-methyl-mannosamine, N -Ethyl-mannosamine, di-arabitylamine, etc. can be mentioned. The reaction between the crosslinked polymer having a halomethyl group obtained by the above method and the above-mentioned specific amine is carried out under heating at a temperature of 20 to 100°C for 2 to 20 hours in the presence of a suitable solvent. As a solvent, in addition to water, ether solvents such as dioxane, acetone,
Examples include ketone solvents such as methyl ethyl ketone, halogenated hydrocarbon solvents such as chloroform, dichloroethane, and chlorobenzene, aromatic hydrocarbon solvents such as benzene and toluene, and alcohol solvents such as methanol and ethanol. Further, at this time, potassium iodide, sodium hydroxide, etc. can be added to promote the reaction. Furthermore, examples of the anion exchange resin used in the present invention include aminopolyol-type anion exchange resins obtained by reacting phenols with amines of the above general formula [] and then condensing them with aldehydes. . In this way, it is possible to produce the aminopolyol type anion exchange resin of the present invention, which has a volume swelling degree of 8 to 30 and is represented by the above formula []. The aminopolyol type anion exchange resin of the present invention exhibits properties as a so-called chelating anion exchange resin due to the aminopolyol group. As a method for concentrating boron isotopes using the anion exchange resin of the present invention obtained by the above method,
In general, so-called column chromatography is performed in which a boric acid solution is passed through a tower filled with the anion exchange resin, boric acid is adsorbed onto the resin layer, and then the boric acid adsorption zone is developed by the acid solution. It is done by twisting. The boric acid concentration when forming a boric acid adsorption zone using the above anion exchange resin of the present invention is 0.2
-2.0 mol (M)/. Examples of acids used for development include hydrochloric acid and sulfuric acid. Further, the concentration of the acid used for this development can be in the range of 0.2 to 2.0M/. The higher the operating temperature for boron isotope separation, the higher the isotope exchange reaction rate, and the lower the pressure loss in the ion exchange column during the separation operation due to the lower solution viscosity. Therefore, a high temperature is preferable, but due to the heat resistance of the resin used for a long time, etc.
A range of 0.degree. C. is preferred. The lower the concentration of the boric acid solution during development, that is, the concentration of the boric acid solution formed as a result of displacement by the mineral acid in the mineral acid solution, the greater the separation coefficient of boron isotopes, which is advantageous. It is. The concentration of this boric acid solution tends to decrease as the developed concentration increases. It can also be lowered by lowering the concentration of mineral acid used for development, but an excessive reduction in mineral acid concentration is not necessarily advantageous because it increases the amount of mineral acid solution required for development. . Therefore, the concentration of mineral acid and the developing temperature are within the range mentioned above, and the concentration of the boric acid solution during development is from 0.2 to
It is economical to select a range of 2M/. The particle size of the anion exchange resin of the present invention is determined by the isotope exchange reaction rate in boron isotope separation, the adsorption/desorption rate between boric acid and the acid used in the acid development, and the ion exchange tower filled with the resin. Although it is determined in consideration of pressure loss and the like, the average particle diameter of the resin can be in the range of 50 to 300 μm within the above boric acid concentration and operating temperature range. Furthermore, under the above conditions, the rate of development of the boric acid adsorption zone by acid using an ion exchange tower filled with the resin is determined by taking into account the isotope exchange reaction rate of the resin and the pressure loss of the ion exchange tower. If the development speed is slow, the productivity of separating and enriching boron isotopes will decrease,
If the speed is too high, the linear velocity of the developing solution will also be high, which may result in too large a pressure loss in the ion exchange tower or impede the regeneration of the resin in the ion exchange tower after acid development. In terms of the range, a flow velocity (LV) of 0.5 to 20 m/hr is preferred. Next, a method for separating and concentrating boron isotopes using an ion exchange column filled with an anion exchange resin of the present invention will be explained. Examples include a through method, a substitution expansion method, and a method using a combination of a reverse breakthrough method and a substitution expansion method. Reverse breakthrough method (Bull.Chem.Soc.
(JPN Vol. 53, No. 7, p. 1860) An example of the method of the present invention using the reverse breakthrough method will be explained with reference to FIG. C ₁ to C ₆ in Figure 1
is an ion exchange column filled with the anion exchange resin of the present invention described above. The temperature inside the column is kept constant by heating the feed liquid and by providing a jacket in the column to circulate hot water or the like, or by providing a heat insulating material. V ₁₁ to V ₁₆ are solution switching valves for supplying liquid to the tower, V ₂₁ to V ₂₆ are solution switching valves for sorting the liquid discharged from the tower, and M ₁ to M ₆ are solution switching valves for supplying liquid to the tower. A detector for monitoring the acid adsorption zone is shown. First, each ion exchange column from C ₁ to C ₆ is regenerated with an alkaline solution such as sodium hydroxide or ammonium hydroxide, and then washed with demineralized water. After that, C ₁ to C ₆ are connected in series, and the liquid is drained from V ₂₆ . At the same time, a boric acid solution is supplied from V ₁₁ until the resin reaches equilibrium. Thereafter, the boric acid adsorbed on the resin is developed with an acid solution from V ₁₁ , and the liquid is drained from V ₂₆ . Continuing to develop with acid, when the sea level at the rear end of the boric acid adsorption zone shifted to the C ₂ tower, the acid supply was switched to V ₁₂ , and the C ₁ tower, which had become an acid adsorption type, supplied alkaline solution from V ₁₁ to V _21. Regeneration by draining from V 11, then supplying demineralized water from V ₁₁ , draining and cleaning from V ₂₁ , then supplying boric acid solution from V ₁₁ , draining from V ₂₁ and cleaning C ₁ An equilibrium amount of boric acid is passed through the resin in the column. This _C1 tower regeneration, water washing,
The process of boric acid adsorption is completed before the rear end interface of the boric acid adsorption zone developed with acid moves from the C ₂ tower to the C ₃ tower, and the rear end interface of the boric acid adsorption zone is
Upon moving to the C ₃ tower, the acid supply was switched to V ₁₃ ,
Connect V ₂₆ to V ₁₁ , drain the solution from V ₂₁ for development of the boric acid adsorption zone, and continue development of the boric acid adsorption zone with acid. Here, C ₂ tower is regenerated in the same way as C ₁ above,
Wash with water and absorb boric acid. By repeating this method, 10B is concentrated at the rear interface of the boric acid adsorption zone. When the 10B concentration reaches a desired concentration, for example, the 10B concentration interface is extracted from the drain valve at the bottom of the ion exchange column, thereby producing a 10B concentrate. Substitution expansion method (J.Am.Chem.Soc., vol. 77, 6125)
Page) An example of separation and concentration using the same anion exchange resin and equipment as in the reverse breakthrough method described above will be explained with reference to FIG. For example, the ion exchange towers from C ₁ to C ₆ are regenerated with an alkaline solution such as sodium hydroxide, washed with demineralized water, connected in series from the C ₁ tower to the C ₃ tower, and a boric acid solution is supplied from V ₁₁ .
Drain the V ₂₃ and pass the boric acid solution through until complete equilibrium is reached. Next, the C ₁ column is connected to the C ₅ column, and an acid solution is supplied from V ₁₁ to perform displacement development of the boric acid adsorption zone. The rear end interface of the boric acid adsorption zone is
When moving to the C ₂ column, the acid supply is switched from V ₁₁ to V ₁₂ and at the same time the C ₆ column is connected and the waste liquid is transferred from V ₂₅ to V ₂₆ .
to continue replacement expansion. On the other hand, the C ₁ column, which has completed the acid development, is regenerated by supplying an alkaline solution from V ₁₁ and draining it from V _21. Similarly, it is then washed with water and prepared for the next development. The regeneration and water washing operations of the C ₁ tower are completed until the rear end interface of the boric acid adsorption zone is transferred to the C ₃ tower. When the rear end interface of the boric acid adsorption zone moves to the C ₃ column, the acid supply is started from V ₁₂ .
Switch to V ₁₃ and connect the C ₆ tower and then the C ₁ tower to drain the liquid.
Continue substitution expansion by starting from V ₂₁ . During this time
The _C2 tower will be regenerated and washed with water. By repeating this method, 11B is concentrated at the front end interface of the boric acid adsorption zone, and 10B is concentrated at the rear end interface, and when each reaches the desired concentration, for example, each interface closes the drain valve at the bottom of the ion exchange column. When passing through the boric acid, the number of moles of boric acid corresponding to the amount of boric acid extracted is extracted from the boric acid supply valve at the top of the ion exchange column, and the boric acid is extracted from the boric acid adsorption zone where the isotopic composition is the same as that of the raw boric acid. By the method of supplying boric acid supply liquid as it passes through the valve.
Production of 10B and 11B concentrates and supply of raw boric acid will take place. A method that combines the reverse breakthrough method and the substitution expansion method. An example of this method will be explained using FIG. 1 as well. For example, the ion exchange towers from C ₁ to C ₆ are regenerated with an alkaline solution such as sodium hydroxide, then washed with demineralized water, and then connected in series from C ₁ to C ₄ towers, and boric acid solution is supplied from V ₁₁ . Then drain the V ₂₄ and pass the boric acid solution through it until complete equilibrium is reached. Similarly to the next reverse breakthrough method, the boric acid adsorbed on the resin is developed from V ₁₁ with an acid solution, and the liquid is drained from V ₂₄ . At this time, the boric acid solution is supplied to the _C5 column from _V15 , drained from _V25 , and the boric acid solution is passed through the _C5 column until complete equilibrium is reached. Continue to develop by supplying acid from V ₁₁ , and when the rear end interface of the boric acid adsorption zone moves to the C ₂ tower, the acid supply is switched from V ₁₁ to V ₁₂ , and at the same time after the C ₄ tower.
Deployment is carried out by connecting the C ₅ column and draining the V ₂₅ . Here, while the rear end interface of the boric acid adsorption zone advances through the C ₂ tower, boric acid solution is supplied from V ₁₆ to the C ₆ tower.
Drain liquid from V ₂₆ and adsorb boric acid to C ₆ column,
The C ₁ column, which has become an acid-adsorbing type after completion of development, is regenerated by supplying an alkaline solution from V ₁₁ and draining it from V ₂₁ , and then washed with demineralized water. Next, when the rear end interface of the rear end expansion of the boric acid adsorption zone development by acid moves to the C ₃ tower, the acid supply is switched to V ₁₃ , the C ₆ tower is connected after the C ₅ tower, and the liquid is drained from V ₂₆ . At this time, the C ₁ tower adsorbs boric acid, and the C ₂ tower performs regeneration and water washing. By repeating this operation, 10B becomes concentrated at the rear interface of the boric acid adsorption zone.
When 10B is concentrated to the target concentration or close to it, the boric acid adsorption zone is stopped with acid to stop the boric acid adsorption to the ion exchange tower in front of the ion exchange tower that is deployed in the series, and the ion exchange tower is Perform replacement expansion by switching from the tower series to the 5 tower series. By repeating the displacement development of the boric acid adsorption zone, regeneration of the developed tower, and water washing, 10B concentration further progressed at the rear end of the boric acid adsorption zone, and after switching to displacement deployment at the front end interface, 10B was accumulated at the rear end interface. 11B will be concentrated in proportion to the amount of 10B concentrated. After that, at appropriate intervals, for example, when the front end and rear end interfaces of the boric acid adsorption zone each pass through a drain valve at the bottom of the column, the 11B concentrate and the 10B concentrate are extracted and the number of moles of raw material corresponding to the number of moles extracted is extracted. The boric acid solution is supplied from the boric acid solution supply valve at the top of the ion exchanger to the same isotopic composition ratio as the raw material boric acid in the boric acid adsorption zone. , 10B and 11B concentrate production and supply of raw material boric acid. This method is suitable for producing 10B concentrates, especially high concentrates. The reason why the anion exchange resin of the present invention is effective in separating and concentrating boron isotopes has not yet been clearly elucidated, but is thought to be as follows. In other words, in boron isotope enrichment using an aminopolyol type anion exchange resin, as the volume change rate expressed by the above formula [] increases, the HETP value decreases, the boric acid exchange reaction rate improves, and boron Even if the boric acid adsorption zone for isotope enrichment is shortened, the number of stages required for concentration can be secured sufficiently, and the moving speed of the boric acid adsorption zone can be improved, making it possible to perform extremely efficient boron isotope separation. can. However, if a resin with an excessively large volume change rate is used,
Free amine type or boric acid adsorption type of the resin used,
Because the volume change with the acid adsorption type becomes large, a particularly significant volume change occurs at the rear end interface of the boric acid adsorption zone, resulting in an excessive pressure loss within the resin-packed column, and If the volume change rate is too large, it will be necessary to ensure a large gap on the interface of the upper part of the resin in the column. This results in a large amount of solution mixing in this part, and in cases where the separation effect per column is small, such as in the case of boron isotope separation, a problem arises in that the efficiency is extremely reduced. Therefore, in boron isotope separation using an aminopolyol type anion exchange resin, taking the above points into account, using a resin with a volume change rate of 8 to 30 will improve the boron isotope exchange reaction rate. It is thought that boron isotopes can be separated quickly, efficiently, and stably. Such a resin does not exist in the commercially available products, and Amberlite IRA-743 (formerly known as XE243) described in French Patent No. 1520521 has a small volume change rate of 6, and Diaion CRB02 has a small volume change rate of 6.
Therefore, the isotope exchange reaction rate is slow, and it cannot necessarily be said that it is a good resin for boron isotope separation. Next, detailed embodiments of the present invention will be explained with reference to examples, but the present invention is not limited to the following examples. Example 1 A crosslinked copolymer prepared by adding 95 g of i-octane as a precipitation solvent to 90 g of styrene and 8 g of 55% divinylbenzene was chloromethylated with chloromethyl ether, and functionalized with N-methyl-D-glucamine. Anion exchange resin introduced as a base (acid adsorption capacity 2.95meq/g resin, moisture 64% average particle size
200 microns, uniformity coefficient 1.25, volume change rate 9.5) in free amine form was filled in six jacketed glass columns with an inner diameter of 10 mm and a length of 1000 mm, each with 75 ml, and these were connected in series (Figure 1). Pass constant temperature water at 60°C through the jacket to maintain the inside of the column at 60°C.
Boron isotopes were separated using the reverse breakthrough method. That is, first, 2000ml of 0.6M boric acid aqueous solution preheated to 60℃ was poured into the first column at a flow rate of LV1m/hr.
The liquid was drained from the sixth column, and boric acid was adsorbed onto the resin in the sixth column. Next, a 0.6N hydrochloric acid aqueous solution preheated to 60°C is passed from the first column at a flow rate of LV1 m/hr to develop the boric acid adsorbed on the resin, and the boric acid aqueous solution flowing out from the sixth column is poured into 5 ml portions. The boric acid concentration was analyzed and found to be 0.83M/. The boron isotope ratio of 10B/11B in this boric acid aqueous solution was measured using a CH-5 type solid mass spectrometer manufactured by Varian Mats. At this time, the time required from the start to the end of development with 0.6N hydrochloric acid aqueous solution was 10.2 hours.
The moving speed of the rear end interface of the boric acid adsorption zone was 55.7 cm/hr. From the above, the 10B concentration at the last end of the boric acid adsorption zone when the boric acid adsorption zone is developed by the 6-column reverse breakthrough method is the 10B concentration in the natural composition raw material boric acid that was first adsorbed on the resin. 19.85%,
It was found that 10B was concentrated at the rear end interface of the boric acid adsorption zone over a length of about 45 cm. The separation factor calculated from this is 1.015,
HETP was 14.4mm. For reference,
Some of the raw materials and physical properties are shown in Tables 1 and 2 for comparison.
Shown in the table. Comparative Example 1 The column of Example 1 was packed with six free amine forms of Diaion CRB02 (average particle size 100 microns, uniformity coefficient 1.3, volume change rate 6.1) into which N-methyl-D-glucamine was introduced as a functional group. , series, and separated boron isotopes using the reverse breakthrough method. In other words, start from the first tower.
Flow rate of 2000ml of 0.6N hydrochloric acid aqueous solution preheated to 60℃
It circulated at a LV of 1 m/hr, and the liquid was drained from the 6th column, and boric acid was adsorbed on the resin in the 6th column. Next, from the first column, 0.6N hydrochloric acid aqueous solution preheated to 60℃ was introduced at a flow rate.
The boric acid adsorbed on the resin was developed by passing the liquid at LV1m/hr, and the boric acid aqueous solution flowing out from the 6th column was collected in 5ml portions and the boric acid concentration was analyzed.
It was 0.48M/. The time required to develop the six columns at this time is
In 10.9 hours, the interfacial movement rate at the rear end of the boric acid adsorption zone is
It was 52.5cm/hr. Next, when the boron isotope ratio of the fractionated boric acid aqueous solution was measured, the 10B concentration at the last end of the boric acid adsorption zone was as follows.
24.1%, and 10B was concentrated at the rear interface of the boric acid adsorption zone over a length of about 65 cm. The separation factor calculated from this is 1.016,
HETP was 42mm. The results are also listed in Table 2 for comparison. Example 2 and Comparative Example 2 Styrene, divinylbenzene, i-octane as a precipitation solvent, and toluene as a swelling solvent were combined as shown in Table 1 and polymerized. Next, this crosslinked copolymer was chloromethylated with chloromethyl methyl ether, and N-methyl-D-glucamine was introduced as a functional group to synthesize an anion exchange resin (average particle size 100 microns, uniformity coefficient 1.4). .

[Table] The free amine forms of these resins were added to each of the two jacketed glass columns used in Example 1.
ml each, connected in series, and as in Example 1, 0.6M boric acid solution was first adsorbed onto the resin at 60°C, then 0.6N hydrochloric acid aqueous solution was adsorbed at 60°C at a flow rate.
The boric acid adsorbed on the resin was developed by flowing the resin at a LV of 1 m/hr, and the flowing boric acid aqueous solution was collected, and HETP was determined from its isotope analysis.
The results are shown in Table 2 along with the volume change rate of the resin used. Amberlite with a volume change rate of 6.3 as a comparative example
100~ by crushing 20~50mesh products of IRA-743
Boron isotopes were separated in the same manner as in Example 2 using 200 mesh to determine HETP. This is shown in Table 2.

[Table] As is clear from Table 2, the volume change rate is 8 to 30
of aminopolyol type anion exchange resin
This shows that HETP is significantly different and smaller. The relationship between the volume change rate and HETP in Table 2 is
As shown in the figure.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an ion exchange resin column, its piping, and valves for carrying out the present invention. Figure 2 shows the volume change rate obtained in Example 2 and
This is a diagram showing the relationship with HETP, and the vertical axis is HETP.
, and the horizontal axis shows the volume change rate. _C1 to _C6 ...anion exchange column, _V11 to _V16 ...valve, _V21 to _V26 ...valve, _M1 to _M6 ...detector, 1...volume change rate-HETP curve.

Claims (1)

[Claims] 1. When boric acid is passed through an ion exchange resin layer made of an aminopolyol type anion exchange resin to form a boric acid adsorption zone, and then an acid solution is passed through to concentrate boron isotopes. An anion exchange resin used for boron isotope concentration, characterized in that the volume change rate expressed by the following formula [] is 8 to 30. Volume change rate = V ₂ − V ₁ /V ₁ ×100 ... [1] However, V ₁ : Volume of free amine type resin in water V ₂ : Volume of hydrochloric acid adsorption type resin in water 2 Scope of Claims In the anion exchange resin for boron isotope enrichment described in item 1, the aminopolyol type anion exchange resin has the general formula [] [However, in the formula, n represents an integer of 1 to 6,
R is a hydrogen atom, _an alkyl group having 1 to 5 carbon atoms, or _-CH2 [-CH(OH)]- _nCH2OH (in the formula, m is 0,
(representing an integer from 1 to 6)] An anion exchange resin for concentrating boron isotopes, characterized in that it is a resin having an aminopolyol group represented by the following as a functional group.