Process for the separation of boron isotopes

Abstract

This application provides a method for separating boron isotopes, comprising: Step S1: pretreating a resin containing pyridine groups to obtain a chlorinated resin or a hydroxylated resin; Step S2: preparing an aqueous solution of boric acid containing boric acid and an oxygen-containing complexing agent, wherein the oxygen-containing complexing agent is selected from one or more of α-hydroxy acids, β-hydroxy acids, compounds simultaneously bonded with α-hydroxy acids and β-hydroxy acids, L-ascorbic acid, gallic acid, and 3-nitrocatechol; Step S3: contacting the chlorinated resin or the hydroxylated resin with the aqueous solution of boric acid prepared in Step S2, thereby enriching boron-10 in one of the resin phase or the solution phase, and enriching boron-11 in the other, thereby achieving the separation of boron-10 and boron-11; Step S4: eluting the resin phase with an eluent to obtain an eluent and eluted resin. The method of this application has a high separation efficiency of boron-10 and boron-11.

Description

Technical Field

[0001] This application relates to the field of isotope separation technology, and in particular to a method for separating boron isotopes. Background Technology

[0002] In nature, boron has two stable isotopes, boron-10 and boron-11, with natural abundances of 19.8% and 80.2%, respectively. High-abundance boron isotope products have wide applications in modern industry, medicine, and other fields. Therefore, there is a very urgent need to conduct research on boron isotope separation (enrichment) and related methods.

[0003] Currently, methods for separating boron isotopes include chemical exchange distillation, laser separation, cryogenic distillation, ion exchange chromatography, metal-organic framework adsorption, and extraction. Among these, chemical exchange distillation is the only industrially applied method for boron isotope separation to date, with a separation factor (S) of approximately 1.030. Cryogenic distillation has reached the pilot-scale stage, with a separation factor (S) of approximately 1.008. Both methods use boron trifluoride as the medium, which has drawbacks such as complex instrument operation and the corrosive nature of boron trifluoride. Other methods are still in the laboratory research stage. The current technical challenge lies in improving the separation efficiency of boron isotopes.

[0004] Therefore, it is necessary to develop an efficient method for separating boron isotopes. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a method for efficiently separating boron isotopes.

[0006] This application provides a method for separating boron isotopes, comprising: step S1: pretreating a resin containing pyridine groups to obtain a chlorinated resin or a hydroxylated resin; step S2: preparing an aqueous solution of boric acid containing boric acid and an oxygen-containing complexing agent, wherein the oxygen-containing complexing agent is selected from one or more of α-hydroxy acids, β-hydroxy acids, α-β-hydroxy acids, L-ascorbic acid, gallic acid, and 3-nitrocatechol; step S3: contacting the chlorinated resin or the hydroxylated resin with the aqueous solution of boric acid prepared in step S2, thereby enriching boron-10 in one of the resin phase or the solution phase, and enriching boron-11 in the other, thereby achieving the separation of boron-10 and boron-11; step S4: eluting the resin phase with an eluent to obtain an eluent and eluted resin.

[0007] In some embodiments, the pyridine-containing resin is selected from one or more of cross-linked poly(4-vinylpyridine) resin, poly(4-vinylpyridine) resin, poly(2-vinylpyridine) resin, and poly(3-vinylpyridine) resin.

[0008] In some embodiments, the α-β-hydroxy acid is selected from citric acid.

[0009] In some embodiments, the α-hydroxy acid is selected from (s)2-hydroxybutyric acid.

[0010] In some embodiments, in step S2, the aqueous boric acid solution contains 0.01 mol / L to 0.7 mol / L of boric acid and 0.01 mol / L to 1.8 mol / L of an oxygen-containing complexing agent.

[0011] In some embodiments, the pretreatment includes: sequentially soaking the resin containing pyridine groups in deionized water, shaking or soaking it in an aqueous HCl solution, and then washing the resin containing pyridine groups that has been shaken or soaked in the aqueous HCl solution with deionized water until neutral to obtain a chlorinated resin; or preparing a chlorinated resin according to the above process, shaking or soaking the chlorinated resin in an alkaline solution, and then washing the chlorinated resin that has been shaken or soaked in the alkaline solution with deionized water until neutral to obtain a hydroxylated resin.

[0012] In some embodiments, contacting the chlorinated resin or hydroxide resin with the boric acid aqueous solution prepared in step S2 in step S3 includes: mixing the chlorinated resin or hydroxide resin with the boric acid aqueous solution prepared in step S2, thereby enriching boron-10 in one of the resin phase or the solution phase, and enriching boron-11 in the other; wherein the method further includes performing solid-liquid separation on the resin phase and the solution phase before step S4.

[0013] In some embodiments, the chlorinated resin or hydroxyl resin is mixed with the boric acid aqueous solution prepared in step S2 at a temperature of 5°C to 30°C.

[0014] In some implementations, the above mixing is carried out for 0.5 h to 24 h.

[0015] In some embodiments, contacting the chlorinated or hydroxylated resin with the boric acid aqueous solution prepared in step S2 in step S3 includes: loading the chlorinated or hydroxylated resin into a chromatographic column, loading the boric acid aqueous solution prepared in step S2, and passing the column through a flow rate of 0.1 cm / min to 10 cm / min, thereby enriching boron-10 in one of the resin phase or the eluent, while enriching boron-11 in the other, thereby achieving the separation of boron-10 and boron-11.

[0016] In some implementations, the column temperature is between 5°C and 30°C.

[0017] In some implementations, the column transit time is from 2 hours to 200 hours.

[0018] In some embodiments, the method further includes: step S5: sequentially contacting the eluted resin obtained in step S4 with a 0.01 mol / L to 0.5 mol / L alkaline aqueous solution and deionized water to regenerate the resin.

[0019] The method for separating boron isotopes in this application has at least the following technical advantages: 1. The method of this application has high separation efficiency of boron-10 and boron-11.

[0020] 2. Through multi-stage cascade and other methods, the method of this application can obtain high abundance of boron-10 (≥95%) and boron-11 (≥99%) isotopes.

[0021] 3. The method of this application uses boric acid aqueous solution as a medium for the separation of boron isotopes. Compared with the boron isotope separation method using boron trifluoride medium, it is greener, more environmentally friendly, uses readily available raw materials, and is safer, thus reducing the separation cost of enriching boron-10 and boron-11. Attached Figure Description

[0022] Figure 1 A flowchart illustrating the operation of a method according to an embodiment of this application is shown. Detailed Implementation

[0023] The technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the implementation methods of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0024] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In the event of any conflict, this specification shall prevail.

[0025] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or method that comprises a list of elements includes not only the elements expressly stated, but also other elements not expressly listed, or elements inherent to implementing the product, method, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other related elements in the product or method that includes that element.

[0026] In nature, boron has two stable isotopes, boron-10 and boron-11, with natural abundances of 19.8% and 80.2%, respectively. High-abundance boron isotope products have wide applications in modern industry, medicine, and other fields. Therefore, there is a very urgent need to conduct research on boron isotope separation (enrichment) and related methods.

[0027] Currently, methods for separating boron isotopes include chemical exchange distillation, laser separation, cryogenic distillation, ion exchange chromatography, metal-organic framework adsorption, and extraction. Among these, chemical exchange distillation is the only industrially applied method for boron isotope separation to date, with a separation factor (S) of approximately 1.030. Cryogenic distillation has reached the pilot-scale stage, with a separation factor (S) of approximately 1.008. Both methods use boron trifluoride as the medium, which has drawbacks such as complex instrument operation and the corrosive nature of boron trifluoride. Other methods are still in the laboratory research stage. The current technical challenge lies in improving the separation efficiency of boron isotopes.

[0028] Therefore, it is necessary to develop an efficient method for separating boron isotopes.

[0029] In view of this, this application provides a method for separating boron isotopes, the method comprising: step S1: pretreating a resin containing pyridine groups to obtain a chlorinated resin or a hydroxylated resin; step S2: preparing an aqueous solution of boric acid containing boric acid and an oxygen-containing complexing agent, wherein the oxygen-containing complexing agent is selected from one or more of α-hydroxy acids, β-hydroxy acids, α-β-hydroxy acids, L-ascorbic acid, gallic acid, and 3-nitrocatechol; step S3: contacting the chlorinated resin or the hydroxylated resin with the aqueous solution of boric acid prepared in step S2, thereby enriching boron-10 in one of the resin phase or the solution phase, and enriching boron-11 in the other, thereby achieving the separation of boron-10 and boron-11; step S4: eluting the resin phase with an eluent to obtain an eluent and eluted resin.

[0030] Ion exchange chromatography is considered a low-energy, economical, and environmentally friendly separation technique. To efficiently separate boron isotopes, the key lies in researching and developing highly efficient separation resins (ion exchange resins, extraction resins, etc.) and improving the separation efficiency of the process.

[0031] Studies have shown that resins containing pyridine groups exhibit some selectivity for boron isotopes in boric acid aqueous solutions, but the selectivity is relatively low. When the oxygen-containing complexing agent described in this application is added to the boric acid aqueous solution and the resulting solution is contacted with the resin containing pyridine groups, the separation effect on boron isotopes is significantly improved, ultimately achieving highly efficient separation of boron isotopes. Furthermore, in this application, because boric acid aqueous solution is used as the isotope separation medium, compared to boron isotope separation methods using boron trifluoride as the medium, it has the advantages of a greener, more environmentally friendly separation process, readily available raw materials, and higher safety, while also reducing the cost of separating and enriching boron-10 and boron-11.

[0032] In this application, the single-level separation factor 10 / 11S is a key reference for evaluating the separation effect of adsorbent on different components in a mixture. In this application, the separation factor... 10 / 11 S was used to evaluate the separation effect of pyridine-containing resins on boron isotopes; the separation factor was... 10 / 11 The further the S-value deviates from 1, the better the separation effect of the system. Single-stage separation factor. 10 / 11 S can be calculated using the following methods: (1) In the formula 10 B / 11 B represents the boron isotope abundance ratios with mass numbers of 10 and 11; c0 and c1 represent the boron concentrations in the boric acid aqueous solution phases before and after adsorption, respectively, in mol / L; α0 and α1 represent the boron isotope abundance ratios in the boric acid aqueous solution phases before and after adsorption, respectively. 10 / 11 B; resin indicates the resin phase, and solution indicates the solution phase.

[0033] In this application, α-hydroxy acid refers to a hydroxy acid comprising at least one α-hydroxy group, where α-hydroxy refers to a hydroxyl group attached to the first carbon atom (α-carbon) adjacent to the carboxyl group. Exemplarily, α-hydroxy acid is selected from (s)2-hydroxybutyric acid.

[0034] In this application, β-hydroxy acid refers to a hydroxy acid that includes at least one β-hydroxy group, where β-hydroxy refers to a hydroxyl group attached to a second carbon atom (β-carbon) adjacent to the carboxyl group.

[0035] In this application, α-β-hydroxy acid refers to a hydroxy acid that includes both α-hydroxy and β-hydroxy groups, where α-hydroxy and β-hydroxy groups may refer to the same hydroxyl group. For example, α-β-hydroxy acid may be selected from citric acid.

[0036] In some embodiments, the pyridine-containing resin is selected from one or more of cross-linked poly(4-vinylpyridine) resin, poly(4-vinylpyridine) resin, poly(2-vinylpyridine) resin, and poly(3-vinylpyridine) resin; alternatively, the pyridine-containing resin is selected from one or more of cross-linked poly(4-vinylpyridine) resin and poly(4-vinylpyridine) resin. Exemplarily, the pyridine-containing resin may be selected from Reillex@HP ion exchange resin (available from Sigma), Reillex... @ One or more of 402 ion exchange resins (available from Sigma).

[0037] In some embodiments, the resin containing a pyridine group is selected from one or more resins containing aminopyridine and resins containing methylpyridine.

[0038] In this application, crosslinked poly(4-vinylpyridine) resin refers to the crosslinking product of poly(4-vinylpyridine) resin.

[0039] In some embodiments, in step S2, the boric acid aqueous solution contains 0.01 mol / L to 0.7 mol / L of boric acid and 0.01 mol / L to 1.8 mol / L of an oxygen-containing complexing agent. This facilitates the bonding of boric acid and the oxygen-containing complexing agent in the aqueous phase to form boron compounds, thereby improving the separation effect of boron isotopes. Exemplarily, the concentration of boric acid in the boric acid aqueous solution is a value within a range of 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.07 mol / L, 0.09 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, or any combination thereof. For example, the concentration of the oxygen-containing complexing agent in the boric acid aqueous solution is a value within the range of 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.07 mol / L, 0.09 mol / L, 0.1 mol / L, 0.4 mol / L, 0.7 mol / L, 1.0 mol / L, 1.3 mol / L, 1.6 mol / L, 1.8 mol / L, or any two of these.

[0040] In some embodiments, the pretreatment includes: sequentially soaking the pyridine-containing resin in deionized water, shaking or soaking it in an HCl aqueous solution, and then washing the pyridine-containing resin that has been shaken or soaked in the HCl aqueous solution with deionized water until neutral, to obtain a chloride-form resin. By performing the above pretreatment on the pyridine-containing resin, impurities in the resin can be removed, and it can be converted into a chloride-form anion exchange resin, ensuring that the resin reaches its optimal working state.

[0041] In some embodiments, the soaking time in deionized water during the pretreatment step is 2 to 7 hours. This facilitates the thorough removal of water-soluble impurities from the resin. Exemplarily, the soaking time in deionized water is a value within a range of 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or any combination thereof.

[0042] In some embodiments, the concentration of the HCl aqueous solution used for shaking or soaking the pyridine-containing resin is from 0.01 mol / L to 0.5 mol / L. In some embodiments, the shaking time of the HCl aqueous solution is from 2 h to 6 h, or the soaking time of the HCl aqueous solution is from 12 h to 48 h. This facilitates the complete conversion of the resin to the chloride form, ensuring that the resin reaches its optimal working state. Exemplarily, the concentration of the HCl aqueous solution is a value within the range of 0.01 mol / L, 0.04 mol / L, 0.07 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or any two of these values. Exemplarily, the shaking time of the HCl aqueous solution is a value within the range of 2 h, 3 h, 4 h, 5 h, 6 h, or any two of these values, or the soaking time of the HCl aqueous solution is a value within the range of 12 h, 17 h, 22 h, 27 h, 32 h, 40 h, 48 h, or any two of these values.

[0043] In some embodiments, the pretreatment includes: preparing the chlorine-form resin according to the above process, shaking or soaking the chlorine-form resin with an alkaline solution, and then washing the chlorine-form resin shaken or soaked in the alkaline solution with deionized water until neutral to obtain the hydroxyl-form resin.

[0044] In some embodiments, the alkaline solution used for shaking or soaking the chlorinated resin in the pretreatment step is a 0.01 mol / L to 0.5 mol / L NaOH aqueous solution. In some embodiments, the shaking time of the alkaline solution in the pretreatment step is 2 h to 6 h, or the soaking time of the alkaline solution is 12 h to 48 h. This facilitates the complete conversion of the chlorinated resin into a hydroxyl-containing hydroxyl resin. Exemplarily, the alkaline solution is an aqueous NaOH solution with a concentration of 0.01 mol / L, 0.04 mol / L, 0.07 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or a value within a range of any two of these concentrations. For example, the shaking time of the alkaline solution is a value between 2h, 3h, 4h, 5h, 6h or any two of these, or the soaking time of the alkaline solution is a value between 12h, 17h, 22h, 27h, 32h, 40h, 48h or any two of these.

[0045] In some embodiments, contacting the chlorinated or hydroxylated resin with the boric acid aqueous solution prepared in step S2 in step S3 includes: mixing the chlorinated or hydroxylated resin with the boric acid aqueous solution prepared in step S2, thereby enriching boron-10 in one of the resin phase or the solution phase, and enriching boron-11 in the other; wherein the method further includes performing solid-liquid separation on the resin phase and the solution phase before step S4. Here, the method of solid-liquid separation is not specifically limited, and common solid-liquid separation methods in the art can be used, such as centrifugation, vacuum filtration, etc.

[0046] In some embodiments, the chlorinated or hydroxylated resin is mixed with the boric acid aqueous solution prepared in step S2 at a temperature of 5°C to 30°C. In some embodiments, the mixing is carried out for 0.5 h to 24 h. This facilitates a complete reaction. Exemplarily, the mixing is carried out at temperatures ranging from 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, or any combination thereof. Exemplarily, the mixing is carried out for 0.5 h, 0.7 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, or any combination thereof.

[0047] In some embodiments, contacting the chlorinated or hydroxylated resin with the boric acid aqueous solution prepared in step S2 in step S3 includes: loading the chlorinated or hydroxylated resin into a chromatographic column, loading the boric acid aqueous solution prepared in step S2, and passing the column through it at a flow rate of 0.1 cm / min to 10 cm / min, thereby enriching boron-10 in one of the resin phase or the eluent, and enriching boron-11 in the other, thus achieving the separation of boron-10 and boron-11. Controlling the flow rate of the boric acid aqueous solution prepared in step S2 within the above range is beneficial for a complete reaction. Exemplarily, the flow rate of the boric acid aqueous solution prepared in step S2 through the chromatographic column is a value between 0.1 cm / min, 0.3 cm / min, 0.5 cm / min, 0.7 cm / min, 0.9 cm / min, 1 cm / min, 3 cm / min, 5 cm / min, 7 cm / min, 9 cm / min, 10 cm / min, or any combination thereof.

[0048] In some embodiments, the column temperature is between 5°C and 30°C. In some embodiments, the column time is between 2 hours and 200 hours. This is beneficial for further improving the adsorption effect. Exemplarily, the column temperature is a value within the range of 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, or any two of these. Exemplarily, the column time is a value within the range of 2 hours, 3 hours, 4 hours, 5 hours, 10 hours, 30 hours, 50 hours, 100 hours, 150 hours, 200 hours, or any two of these.

[0049] The type of eluent used in step S4 of this application is not particularly limited, as long as it can elute the resin phase enriched with boron-10 or boron-11 to obtain the corresponding eluent. In some embodiments, in step S4, an acidic solution is used as the eluent to elute the resin phase enriched with boron-10 or boron-11 to obtain the corresponding eluent and the eluted resin. Exemplarily, the acidic solution used can be an aqueous hydrochloric acid solution, and the concentration of the acidic solution can be from 0.01 mol / L to 1 mol / L. This facilitates thorough elution of the resin. Exemplarily, the concentration of the acidic solution used in step S4 can be a value within the range of 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.07 mol / L, 0.09 mol / L, 0.1 mol / L, 0.4 mol / L, 0.7 mol / L, 1 mol / L, or any two of these values.

[0050] In some embodiments, the method of this application further includes step S5: sequentially contacting the eluted resin obtained in step S4 with an alkaline aqueous solution of 0.01 mol / L to 0.5 mol / L and deionized water to regenerate the resin for recycling. By sequentially contacting the eluted resin obtained in step S4 with an alkaline aqueous solution and deionized water, impurities remaining during the adsorption process can be removed, and the pyridine-containing resin can be reverted back to a hydroxide-type resin, thereby restoring the chemical activity of the resin. Exemplarily, the alkaline aqueous solution used is a sodium hydroxide aqueous solution, and the concentration of the sodium hydroxide aqueous solution is a value within a range of 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.07 mol / L, 0.09 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or any two of these values.

[0051] In this application, in order to increase the abundance of boron isotopes, after a single separation, steps S3 to S5 can be repeated by combining the obtained boron-10 enriched solution with the boric acid aqueous solution prepared in step S2, or by combining the obtained boron-11 enriched solution with the boric acid aqueous solution prepared in step S2, thereby obtaining boron-10 and boron-11 with the desired abundance.

[0052] The method described in this application is also applicable to methods such as multi-stage cascades of chromatographic columns and simulated moving beds.

[0053] The present application will be described in further detail below with reference to specific embodiments. The purpose of this description is merely illustrative and not intended to limit the scope of the present application.

[0054] In the following embodiments, unless otherwise specified, all components used are commercially available products. Furthermore, all equipment and instruments involved are commercially available standardized products, and their operating conditions and parameter settings are in accordance with the standard instructions provided by the equipment manufacturer.

[0055] Example 1 Methods for separating boron isotopes Step S1: Soak the Reillex resin containing pyridine groups in deionized water and then in 0.1 mol / L HCl aqueous solution sequentially. @ Reillex@HP resin, after being soaked in HCl aqueous solution, was then washed with deionized water until neutral to obtain the chloride form resin. The soaking time in deionized water was 12 hours, and the soaking time in HCl aqueous solution was 12 hours. The chloride form resin was then soaked in 0.1 mol / L NaOH aqueous solution, and then washed with deionized water until neutral to obtain the hydroxyl form resin. The soaking time in NaOH aqueous solution was 12 hours. Step S2: Prepare an aqueous solution of boric acid containing boric acid and the oxygen-containing complexing agent citric acid, wherein the concentration of boric acid is 0.1 mol / L and the concentration of citric acid is 0.2 mol / L; Step S3: Weigh 0.2g of the above-mentioned hydroxyl resin and add it to 20.0mL of the boric acid aqueous solution prepared in step S2. Shake at 25°C for 18h and centrifuge to obtain a resin phase enriched with boron-10 and a solution phase enriched with boron-11. Step S4: Elute the boron-10-enriched resin phase with 0.1 mol / L HCl eluent at a volume ratio of 1:3 to obtain a boron-10-enriched eluent.

[0056] Boron isotope single-level separation factor 10 / 11Measurement of S: The boron concentration (c0, c1) in the boric acid aqueous solution before and after adsorption was determined using inductively coupled plasma atomic emission spectrometry (ICP-OES), and the boron isotope abundance ratio in the boric acid aqueous solution before and after adsorption was determined using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). 10 / 11 B(α0, α1), the separation factor of the resin for the boric acid aqueous solution is calculated according to the aforementioned formula (1). 10 / 11 S, measured and calculated, is the single-level separation factor. 10 / 11 S is 1.045.

[0057] Example 2 Methods for separating boron isotopes Step S1: Treat Reillex in the same manner as in Example 1 @ HP resin is pretreated to obtain hydroxyl-type resin. Step S2: Prepare an aqueous solution of boric acid containing boric acid and the oxygen-containing complexing agent L-ascorbic acid, wherein the concentration of boric acid is 0.1 mol / L and the concentration of L-ascorbic acid is 0.2 mol / L; Step S3: Weigh 0.5g of the above-mentioned hydroxyl resin and add it to 50.0ml of the solution prepared in step S2. Shake at 25°C for 18h and centrifuge to obtain a resin phase enriched with boron-11 and a solution phase enriched with boron-10. Step S4: Elute the boron-11-enriched resin phase in the same manner as in Example 1 to obtain a boron-11-enriched eluent.

[0058] The boron isotope unilevel separation factor was measured using the same method as in Example 1. 10 / 11 S. The single-level separation factor was measured and calculated. 10 / 11 S is 0.972.

[0059] Example 3 Methods for separating boron isotopes Step S1: Replace the Reillex@HP resin in Example 1 with Reillex @ 402, Reillex is treated in the same manner as in Example 1. @ 402 resin is pretreated to obtain hydroxyl resin; Step S2: Prepare an aqueous solution of boric acid containing boric acid and the oxygen-containing complexing agent citric acid in the same manner as in Example 1; Step S3: A certain mass of the above-mentioned hydroxyl resin is packed into a chromatographic column. The ratio of the column height to the inner diameter is 50:1, and the column height is 1 meter. The column is kept at 20°C by a constant temperature circulation system. The boric acid aqueous solution prepared in step S2 is loaded and passed through the column at a flow rate of 1 cm / min for 4 hours. The eluent is collected. During the elution process, boron-10 is enriched in the hydroxyl resin phase, thus obtaining a resin phase enriched with boron-10. Step S4: Elute the boron-10-enriched resin phase with 0.1 mol / L HCl eluent at a volume ratio of 1:5 to obtain a boron-10-enriched eluent.

[0060] The boron isotope unilevel separation factor was measured using the same method as in Example 1. 10 / 11 S. The single-stage separation factor was measured. 10 / 11 S is 1.031.

[0061] Obtaining high abundance of boron-10 and boron-11 After step S4, proceed to steps S5 and S6: Step S5: Pass 0.1 mol / L sodium hydroxide aqueous solution and deionized water sequentially through the Reillex solution eluted in step S4. @ 402 resin, to regenerate the resin.

[0062] Step S6: Combine the boron-10 enriched eluent obtained in step S4 with the boric acid aqueous solution prepared in step S2, and then repeat steps S3 to S5 to obtain high-abundance boron-10 (abundance ≥ 95%).

[0063] Comparative Example 1 Methods for separating boron isotopes The boron isotopes were separated in the same manner as in Example 1, except that the oxygen-containing complexing agent citric acid was not added in step S2.

[0064] The boron isotope unilevel separation factor was measured using the same method as in Example 1. 10 / 11 S. The single-stage separation factor was measured. 10 / 11 S is 0.993.

[0065] Therefore, it can be seen that, compared with Examples 1 to 3, Comparative Example 1 did not add the oxygen-containing complexing agent of this application, and the pyridine-containing resin Reillex... @ HP's single-level separation factor for boron isotopes 10 / 11S is 0.993. This value is close to 1, indicating that it has a certain separation effect on boron isotopes, but the separation effect is limited and weaker than that in Examples 1 to 3, and cannot achieve efficient separation of boron isotopes. In contrast, in Examples 1 to 3, due to the addition of the oxygen-containing complexing agent of this application to the boric acid aqueous solution, the resin containing pyridine groups has a significantly improved selectivity for boron isotopes, thereby achieving efficient separation of boron isotopes.

[0066] Comparative Example 2 Methods for separating boron isotopes The boron isotopes were separated in the same manner as in Example 1, except that in step S1, the boron-specific resin Amberlite IRA-743 was used instead of the Reillex@HP resin.

[0067] The boron isotope unilevel separation factor was measured using the same method as in Example 1. 10 / 11 S. The single-stage separation factor was measured. 10 / 11 S is 1.015.

[0068] Comparative Example 3 Methods for separating boron isotopes The boron isotopes were separated in the same manner as in Example 1, except that in step S1, the boron-specific resin Amberlite IRA-743 was used instead of the Reillex@HP resin, and the oxygen-containing complexing agent citric acid was not added.

[0069] The boron isotope unilevel separation factor was measured using the same method as in Example 1. 10 / 11 S. The single-stage separation factor was measured. 10 / 11 S is 1.023.

[0070] The boron-specific resin Amberlite IRA-743 used in Comparative Examples 2 and 3 is a commercially available resin commonly used for separating boron isotopes. It can be seen that the boron-specific resin in Comparative Examples 2 and 3 showed improved separation efficiency for boron isotopes compared to Comparative Example 1, but still inferior to Examples 1 to 3. Therefore, this demonstrates that the boron isotope separation method of this application can achieve better separation results.

[0071] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. All equivalent structural transformations made using the content of this application's specification under the inventive concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for separating boron isotopes, characterized in that, The method includes: Step S1: Pre-treat the resin containing pyridine groups to obtain a chlorinated resin or a hydroxide resin; Step S2: Prepare an aqueous solution of boric acid containing boric acid and an oxygen-containing complexing agent, wherein the oxygen-containing complexing agent is selected from one or more of α-hydroxy acids, β-hydroxy acids, α-β-hydroxy acids, L-ascorbic acid, gallic acid and 3-nitrocatechol; Step S3: Contact the chlorinated resin or the hydroxide resin with the boric acid aqueous solution prepared in step S2, so that boron-10 is enriched in one of the resin phase or the solution phase, while boron-11 is enriched in the other, thereby achieving the separation of boron-10 and boron-11. Step S4: Elute the resin phase with an eluent to obtain an eluent and eluted resin.

2. The method according to claim 1, wherein, The method satisfies one or more of the following: The pyridine-containing resin is selected from one or more of cross-linked poly(4-vinylpyridine) resin, poly(4-vinylpyridine) resin, poly(2-vinylpyridine) resin and poly(3-vinylpyridine) resin; The α-β-hydroxy acid is selected from citric acid; The α-hydroxy acid is selected from (s)2-hydroxybutyric acid.

3. The method according to claim 1 or 2, wherein, In step S2, the boric acid aqueous solution contains 0.01 mol / L to 0.7 mol / L of boric acid and 0.01 mol / L to 1.8 mol / L of the oxygen-containing complexing agent.

4. The method according to any one of claims 1 to 3, wherein, The preprocessing includes: The resin containing pyridine groups is sequentially soaked in deionized water, shaken with HCl aqueous solution, or immersed in water. Then, the resin containing pyridine groups that has been shaken or immersed in the HCl aqueous solution is washed with deionized water until neutral to obtain the chloride form resin; or The chlorine-form resin is prepared according to the above process, and then the chlorine-form resin is shaken or soaked in an alkaline solution. The chlorine-form resin shaken or soaked in the alkaline solution is then washed with deionized water until neutral to obtain the hydroxide-form resin.

5. The method according to any one of claims 1 to 4, wherein, Step S3, contacting the chlorinated resin or the hydroxide resin with the boric acid aqueous solution prepared in step S2, includes: The chlorinated resin or the hydroxide resin is mixed with the boric acid aqueous solution prepared in step S2, so that boron-10 is enriched in one of the resin phase or the solution phase, while boron-11 is enriched in the other. The method further includes performing solid-liquid separation on the resin phase and the solution phase before step S4.

6. The method according to claim 5, wherein, The mixing is carried out at a temperature of 5°C to 30°C, and / or the mixing is carried out for 0.5 h to 24 h.

7. The method according to any one of claims 1 to 6, wherein, The step S3 of contacting the chlorine-form resin or the hydroxyl-form resin with the boric acid aqueous solution prepared in step S2 includes: loading the chlorine-form resin or the hydroxyl-form resin into a chromatographic column, loading the boric acid aqueous solution prepared in step S2, and passing the column through a flow rate of 0.1 cm / min to 10 cm / min, thereby enriching boron-10 in one of the resin phase or the eluent, while enriching boron-11 in the other, thereby achieving the separation of boron-10 and boron-11.

8. The method according to claim 7, wherein, The column temperature ranges from 5°C to 30°C.

9. The method according to claim 7, wherein, The column transit time ranges from 2 hours to 200 hours.

10. The method according to any one of claims 1 to 9, wherein, The method further includes: Step S5: The eluted resin obtained in step S4 is contacted sequentially with 0.01 mol / L to 0.5 mol / L alkaline aqueous solution and deionized water to regenerate the resin.

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