Separation method of boron isotope

Abstract

The invention discloses a boron isotope separation method. The separation method of the boron isotope comprises the following steps: mixing a boric acid aqueous solution with a pH regulator, regulating the pH value of the solution to 6-8, and preparing a to-be-separated sample which contains B (OH) 4 <-> enriched in 10B element; a to-be-separated sample is in contact with the graphene-loaded Fe3O4 composite material, so that the graphene-loaded Fe3O4 composite material adsorbs B (OH) 4 <-> enriched with the 10B element. In a boric acid solution, the boron element exists in forms such as B (OH) 4-and B (OH) 3, and a 10B isotope is more inclined to form a B (OH) 4-form than a 11B isotope. Fe3O4 is loaded on the surface of graphene, the graphene can inhibit aggregation of Fe3O4 nanoparticles, and meanwhile, the graphene has excellent electron conduction performance and an efficient molecular transmission channel, so that the adsorption performance of the Fe3O4 component to B (OH) 4-can be enhanced, the efficient enrichment and separation of 10B isotopes under mild conditions are realized, and the separation factor of the 10B isotopes is increased.

Description

Technical Field

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

[0002] Boron has two stable isotopes in nature. 10 B and 11 B, with natural abundances of 19.9% ​​and 80.1%, respectively. Due to... 10 Boron isotopes have extremely high neutron absorption cross-sections and are used in important fields such as neutron absorber additives in the primary loop of the nuclear industry, BC neutron absorber materials, and raw materials for boron-based nuclear medicine (BNCT). Because... 10 B and 11 The physicochemical properties of boron isotopes B and C are very similar, making their separation challenging. Current boron isotope separation processes mainly include chemical exchange distillation, low-temperature distillation of boron trifluoride, laser separation, and chromatography. Chemical exchange distillation is a relatively mature method, but it suffers from drawbacks such as corrosivity, high energy consumption, and large equipment investment. Low-temperature distillation of boron trifluoride is characterized by high energy consumption and low production efficiency. Chromatography offers advantages such as safety and energy efficiency, but the separation factor of current exchange resins still cannot meet the requirements of industrial applications. While laser separation offers advantages such as a high separation factor, it requires significant equipment investment and is not conducive to industrial application. Current boron isotope separation methods suffer from harsh separation conditions and low separation factors, failing to meet the needs of industrial applications. Summary of the Invention

[0003] Therefore, it is necessary to provide a method for separating boron isotopes to achieve mild separation conditions and a high separation factor.

[0004] In some embodiments, a method for separating boron isotopes is provided, comprising the following steps:

[0005] A boric acid aqueous solution is mixed with a pH adjuster to adjust the pH of the solution to 6-8, and a sample to be separated is prepared. The sample to be separated contains enriched... 10 B(OH)4 of element B - ;

[0006] The sample to be separated is contacted with a graphene-supported Fe3O4 composite material, allowing the graphene-supported Fe3O4 composite material to adsorb and enrich the sample. 10 B(OH)4 of element B - .

[0007] In some embodiments, in the provided method for separating boron isotopes, the concentration of boric acid in the boric acid aqueous solution is 0.1 mol / L to 1 mol / L.

[0008] In some embodiments, the pH adjuster in the provided method for separating boron isotopes includes one or both of sodium hydroxide and potassium hydroxide.

[0009] In some embodiments, in the provided method for separating boron isotopes, the ratio of boron acid in the graphene-supported Fe3O4 composite material and the boric acid aqueous solution is (0.01~0.5) g: (0.1~1) mol.

[0010] In some embodiments, the preparation method of the graphene-supported Fe3O4 composite material includes the following steps:

[0011] Graphene was dispersed in an aqueous solution of iron salts and subjected to hydrolysis under heating conditions, and the solid material was collected.

[0012] The solid material was dried and calcined in an inert gas atmosphere to prepare the graphene-supported Fe3O4 composite material.

[0013] In some embodiments, in the preparation method of the graphene-supported Fe3O4 composite material, the ratio of graphene to iron salt is (30~100) mg: (0.005~0.01) mol.

[0014] In some embodiments, the preparation method of the graphene-supported Fe3O4 composite material satisfies one or both of the following conditions:

[0015] (1) The heating temperature is 70℃~90℃, and the heating time is 8h~16h; and

[0016] (2) The calcination temperature is 500℃~650℃ and the calcination time is 3h~6h.

[0017] In some embodiments, in the preparation method of the graphene-supported Fe3O4 composite material, the iron salt includes one or more of ferric chloride, ferric nitrate, and ferric sulfate.

[0018] In some embodiments, the adsorption time in the provided method for separating boron isotopes is 0.5 h to 6 h.

[0019] In some embodiments, the provided method for separating boron isotopes further includes, after solid-liquid separation, contacting the solid with an eluent to elute and enrich it. 10 B(OH)4 - It is separated from the graphene-supported Fe3O4 composite material.

[0020] In some embodiments, the provided method for separating boron isotopes satisfies one or more of the following conditions:

[0021] (1) The eluent comprises one or more of the following: an aqueous solution of acetic acid, an aqueous solution of hydrochloric acid, an aqueous solution of sulfuric acid, an aqueous solution of nitric acid, and an aqueous solution of phosphoric acid with a pH of 3 to 5;

[0022] (2) The volume ratio of the eluent to the boric acid aqueous solution is (1~2):1; and

[0023] (3) The washing time is 0.5h~6h.

[0024] The aforementioned method for separating boron isotopes involves boron being separated in boric acid solution as B(OH)₄. - It exists in forms such as B(OH)3. 10 B isotope ratio 11 B isotopes tend to form B(OH)4 - Morphology. Fe3O4 is loaded on the surface of graphene. The graphene sheet surface is flexible, and the Fe3O4 nanoparticles embedded in the surface form flexible constraints, which can inhibit the aggregation of Fe3O4 nanoparticles, increase the specific surface area of ​​Fe3O4, and thus improve the separation rate. Simultaneously, graphene has excellent electronic conductivity and efficient molecular transport channels, which can enhance the Fe3O4 component's affinity for B(OH)4. - Its adsorption properties enable efficient enrichment and separation under mild conditions. 10 B isotope, increasing 10 Separation factor for B isotopes. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0027] 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 invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0029] The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B."

[0030] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0031] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items.

[0032] In this application, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0033] In this application, terms such as "preferred," "better," "more suitable," and "ideal" are merely used to describe implementation methods or embodiments that achieve better results, and should be understood not to limit the scope of protection of this application.

[0034] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0035] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0036] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0037] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0038] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0039] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0040] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0041] In this application, "normal temperature" in the context generally refers to 5℃~30℃, and more preferably 25±5℃.

[0042] In this application, "atmospheric pressure" in the context generally refers to one standard atmosphere, preferably 100±10 kPa.

[0043] In some embodiments, a method for separating boron isotopes is provided, comprising the following steps: mixing an aqueous boric acid solution with a pH adjuster to adjust the pH of the solution to 6-8, and preparing a sample to be separated, wherein the sample to be separated contains enriched boron isotopes. 10 B(OH)4 of element B - ;

[0044] The sample to be separated is contacted with a graphene-supported Fe3O4 composite material, allowing the graphene-supported Fe3O4 composite material to adsorb and enrich the sample. 10 B(OH)4 of element B - .

[0045] Fe3O4 is loaded onto the surface of graphene. The graphene sheet surface is flexible, and the Fe3O4 nanoparticles embedded in this surface form a flexible constraint, which inhibits nanoparticle aggregation and increases the specific surface area of ​​Fe3O4, thereby improving the separation rate. Graphene provides a "flexible constraint" effect, reducing the agglomeration of Fe3O4 during repeated adsorption and desorption of boric acid, increasing the number of times the separation material can be reused, and extending its service life. Graphene nanosheets possess excellent electronic conductivity and efficient molecular transport channels, which can enhance the affinity of Fe3O4 components for B(OH)4. - The adsorption performance is further enhanced, thus improving the separation factor. Graphene and Fe3O4 nanoparticles exhibit a layered stacked morphology, and the pores in the lateral pores provide transport channels for boric acid components, ensuring efficient adsorption and desorption of boric acid components. It has a high adsorption capacity and separation factor, realizing efficient enrichment and separation of boron 10 isotopes from boric acid, and can ensure stable separation in multiple cyclic separation processes.

[0046] The provided method for separating boron isotopes utilizes graphene-supported Fe3O4 composite materials to achieve isotope separation from boric acid under normal temperature and pressure conditions, which has the advantage of mild separation conditions.

[0047] In some embodiments, in the provided method for separating boron isotopes, the concentration of boric acid in the boric acid aqueous solution is 0.1 mol / L to 1 mol / L. For example, the concentration of boric acid can be 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, 0.8 mol / L, 0.9 mol / L, 1 mol / L, etc., or it can be a range composed of any two of the aforementioned values.

[0048] In some embodiments, the pH adjuster in the provided method for separating boron isotopes includes one or both of sodium hydroxide and potassium hydroxide.

[0049] In some embodiments, in the provided method for separating boron isotopes, the ratio of the graphene-supported Fe3O4 composite material to the boric acid in the boric acid aqueous solution is (0.01~0.5) g: (0.1~1) mol, for example, 0.01 g: 0.1 mol, 0.01 g: 1 mol, 0.1 g: 0.1 mol, 0.1 g: 0.5 mol, 0.5 g: 0.1 mol, 0.5 g: 1 mol, etc., or it can be a range consisting of any two of the aforementioned ratios.

[0050] In some embodiments, graphene nanosheets loaded with Fe3O4 composite material are prepared by an impregnation reduction process, which enables the adsorption and separation of boron isotopes in boric acid solution.

[0051] In some embodiments, the preparation method of graphene-supported Fe3O4 composite material includes the following steps:

[0052] Graphene was dispersed in an aqueous solution of iron salts and subjected to hydrolysis under heating conditions, and the solid material was collected.

[0053] The solid material was dried and calcined in an inert gas atmosphere to prepare a graphene-supported Fe3O4 composite material.

[0054] In some embodiments, in the preparation method of graphene-supported Fe3O4 composite material, the ratio of graphene to iron salt is (30~100) mg: (0.005~0.01) mol, for example, 30 mg: 0.005 mol, 30 mg: 0.008 mol, 30 mg: 0.01 mol, 50 mg: 0.005 mol, 50 mg: 0.008 mol, 50 mg: 0.01 mol, 100 mg: 0.005 mol, 100 mg: 0.008 mol, 100 mg: 0.01 mol, etc., or it can be a range of any two of the aforementioned ratios.

[0055] In some embodiments, the heating temperature in the preparation method of graphene-supported Fe3O4 composite material is 70℃~90℃, and the heating time is 8h~16h. For example, the heating temperature can be 70℃, 80℃, 90℃, etc., or any combination of the aforementioned two values; the heating time can be 8h, 10h, 12h, 14h, 16h, etc., or any combination of the aforementioned two values.

[0056] In some embodiments, the calcination temperature in the preparation method of graphene-supported Fe3O4 composite material is 500℃~650℃, and the calcination time is 3h~6h. For example, the calcination temperature can be 500℃, 550℃, 600℃, 650℃, etc., or any range of two of the aforementioned values; the calcination time can be 3h, 4h, 5h, 6h, etc., or any range of two of the aforementioned values.

[0057] In some embodiments, the iron salt in the preparation method of graphene-supported Fe3O4 composite material includes one or more of ferric chloride, ferric nitrate, and ferric sulfate.

[0058] In some embodiments, the preparation method of graphene-supported Fe3O4 composite material includes the following steps:

[0059] Graphene was dispersed in a ferric chloride solution and subjected to hydrolysis under heating conditions; the solid material was then collected.

[0060] The solid material was dried and calcined in an inert gas atmosphere to prepare a graphene-supported Fe3O4 composite material.

[0061] In some embodiments, the preparation method of graphene-supported Fe3O4 material is as follows:

[0062] 1) Disperse 30mg~100mg of graphene ultrasonically in 150ml of 0.05 mol / L FeCl3 solution for 1h; carry out hydrolysis reaction at 70℃~90℃ for 8h~16h, and collect the solid material;

[0063] 2) The obtained solid material is repeatedly filtered and washed with deionized water, and then vacuum dried at 60℃~90℃ for 18h~48h;

[0064] 3) Then, the sample was heat-treated at 500℃~650℃ at a heating rate of 5℃ / min and kept at the temperature for 3h~6h under an argon atmosphere to prepare graphene-supported Fe3O4 composite material.

[0065] In some embodiments, the adsorption time in the provided method for separating boron isotopes is 0.5h to 6h. For example, the adsorption time can be 0.5h, 1h, 3h, 5h, 6h, etc., or it can be a range of any two of the aforementioned values.

[0066] In some embodiments, the provided method for separating boron isotopes further includes solid-liquid separation, wherein the separated solid is contacted with an eluent to elute and enrich it. 10 B(OH)4 - Separation from graphene-supported Fe3O4 composite material.

[0067] In some embodiments, the provided method for separating boron isotopes includes an eluent comprising one or more of the following: an aqueous solution of acetic acid, an aqueous solution of hydrochloric acid, an aqueous solution of sulfuric acid, an aqueous solution of nitric acid, and an aqueous solution of phosphoric acid, with a pH value of 3 to 5. For example, the pH value of the eluent can be 3, 4, 5, or any range consisting of two of the aforementioned values.

[0068] In some embodiments, the volume ratio of the eluent to the boric acid aqueous solution is (1~2):1 in the provided method for separating boron isotopes.

[0069] In some embodiments, the elution time in the provided method for separating boron isotopes is 0.5h to 6h. For example, the elution time can be 0.5h, 1h, 3h, 5h, 6h, or any range of two of the aforementioned values.

[0070] The following are specific embodiments. They are intended to provide a more detailed description of this application to help those skilled in the art and researchers better understand it. The technical conditions described do not constitute any limitation on this application. Any modifications made within the scope of the claims of this application are protected by the claims.

[0071] Unless otherwise stated, all raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. Experimental methods not specifying particular conditions in the examples were performed under conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.

[0072] The preparation method of the graphene nanosheet-supported Fe3O4 material used in the examples is as follows:

[0073] 1) 50 mg of graphene nanosheets were ultrasonically dispersed in 150 ml of 0.05 mol / L FeCl3 solution for 1 h; hydrolysis was carried out at 80 °C for 12 h, and the solid was collected.

[0074] 2) The obtained product was repeatedly filtered and washed with deionized water, and then vacuum dried at 90°C for 30 hours;

[0075] 3) Then, the sample was heat-treated at 650℃ with a heating rate of 5℃ / min and kept at the temperature for 6h under an argon atmosphere to prepare graphene nanosheets loaded with Fe3O4 material.

[0076] Example 1

[0077] 0.1 g of graphene nanosheets loaded with Fe3O4 material was weighed and added to 1 L of 0.5 mol / L boric acid aqueous solution. After shaking for 6 h, the solid and liquid were separated by filtration and magnetic separation. The separated solid was enriched with the boric acid aqueous solution. 10B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0078] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were detected, and the boron isotope separation factor and adsorption amount were calculated.

[0079] Example 2

[0080] 0.1 g of graphene nanosheets loaded with Fe3O4 material was weighed and added to 1 L of 0.5 mol / L boric acid aqueous solution. After shaking for 0.5 h, the solid and liquid were separated by filtration and magnetic separation. The separated solid was enriched with the boric acid aqueous solution. 10 B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0081] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were detected, and the boron isotope separation factor and adsorption amount were calculated.

[0082] Example 3

[0083] Weigh 0.5g of graphene nanosheets loaded with Fe3O4 material and add it to 1L of 1mol / L boric acid aqueous solution. After shaking for 6 hours, filter and perform magnetic separation to separate the solid and liquid. The separated solid is the material enriched in the boric acid aqueous solution. 10 B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0084] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were detected, and the boron isotope separation factor and adsorption amount were calculated.

[0085] Example 4

[0086] 0.01 g of graphene nanosheets loaded with Fe3O4 material was weighed and added to a 0.1 mol / L boric acid aqueous solution. After shaking for 6 hours, the solid and liquid were separated by filtration and magnetic separation. The separated solid was enriched with the boric acid aqueous solution. 10B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0087] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were detected, and the boron isotope separation factor and adsorption amount were calculated.

[0088] Comparative Example 1

[0089] 150 ml of 0.05 mol / L FeCl3 solution was hydrolyzed at 80 °C for 12 h, and the precipitate was collected. The precipitate was then vacuum dried at 90 °C for 30 h. The sample was then heat-treated at 650 °C with a heating rate of 5 °C / min and kept at the temperature under an argon atmosphere for 6 h to prepare Fe3O4 material.

[0090] 0.1 g of Fe3O4 material was weighed and added to 1 L of 0.5 mol / L boric acid aqueous solution. After shaking for 6 hours, the solid and liquid were separated by filtration and magnetic separation. The separated solid was the product enriched in the boric acid aqueous solution. 10 B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0091] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were detected, and the boron isotope separation factor and adsorption amount were calculated.

[0092] Comparative Example 2

[0093] Magnetic nanomaterial C@Fe3O4 was prepared as follows: 0.2 g of Fe3O4 nanoparticles were placed in 50 mL of distilled water and sonicated for 20 min to uniformly disperse the Fe3O4 nanoparticles. 0.5 g of sucrose and 0.3–0.70 mL of ethylene glycol were added to the dispersion, mechanically stirred, and sonicated for 1 h to completely dissolve the sucrose and ensure uniform microscopic mixing of the three substances. The mixture was placed in a polytetrafluoroethylene reactor and reacted at 150 °C for 4 h. The resulting product was repeatedly ultrasonically washed with ethanol solution to remove the pore-forming agent ethylene glycol, yielding a black product. This product was then treated with a mixed acid (5 mL of 98% concentrated sulfuric acid, 3 mL of concentrated nitric acid, and 0.5 g of potassium permanganate in 50 mL of distilled water) for 12 h to obtain hollow carbon spheres. Magnetic nanomaterial Fe3O4@CuO was then prepared. 0.2 g of Fe3O4 nanoparticles were mixed with 0.5 g of sucrose in 50 mL of distilled water, mechanically stirred for 30 min, and ultrasonically treated for 20 min to ensure uniform dispersion of the Fe3O4 nanoparticles and thorough mixing with the sucrose. The mixture was placed in a polytetrafluoroethylene reactor and reacted at 150 °C for 4 h. After natural cooling, the product was removed, and uncarbonized sucrose on the surface was separated and washed away using magnetic separation. Low-temperature carbonization was then performed to coat the Fe3O4 surface with a thin layer of carbon, resulting in C@Fe3O4 spheres that protect the Fe3O4 core. The obtained C@Fe3O4 spheres were dispersed in 50 mL of distilled water containing 0.55 mL of ethylene glycol and 0.5 g of sucrose. The mixture was mechanically stirred at room temperature for 30 min and then sonicated for 30 min to ensure that the C@Fe3O4 spheres, ethylene glycol, and sucrose were microscopically homogenized. The mixture was placed in a polytetrafluoroethylene reactor and reacted at 150 °C for 4 h. After cooling, the product was magnetically separated and placed in ethanol as a washing solution. The mixture was sonicated at 100 Hz for 2 h with the washing solution being changed continuously to remove the surface pore-forming agent ethylene glycol, finally obtaining C@Fe3O4 magnetic microporous spheres.

[0094] 0.1 g of C@Fe3O4 material was weighed and added to a 0.5 mol / L boric acid aqueous solution. After shaking for 6 hours, the solid and liquid were separated by filtration and magnetic separation. The separated solid was the product enriched in the boric acid aqueous solution. 10 B of B(OH)4 - Graphene-supported Fe3O4 composite material, with liquid as enrichment 11 B is an aqueous solution of boric acid.

[0095] The solid was added to 1 L of hydrochloric acid aqueous solution with a pH of 3 for elution. After elution for 6 hours, the eluent was collected to obtain the enriched product. 10 Acidic aqueous solution of B. The concentration and isotopic abundance of boric acid in the treated water were measured.

[0096] Boric acid concentration was detected using inductively coupled plasma optical emission spectrometry (ICP-OES), and isotopic abundance was detected using inductively coupled plasma mass spectrometry (ICO-MS). The boron isotope separation factor and adsorption amount were calculated.

[0097] The formula for calculating the boron adsorption capacity Q is: ,

[0098] Q is the equilibrium adsorption capacity, mmol / g;

[0099] C0 is the initial boron concentration in the boric acid solution, in mg / L;

[0100] C1 is the boron concentration in the boric acid solution after adsorption equilibrium, in mg / L;

[0101] M is the atomic mass of boron, 10.81 g / mol;

[0102] m a The value is the mass of the adsorbent, in g / L.

[0103] The formula for calculating the separation factor S is:

[0104] ,

[0105] For the adsorbate in the adsorbent 10 B and 11 The ratio of B abundance;

[0106] At adsorption equilibrium, in the solution 10 B and 11 The ratio of B abundance.

[0107] The test results are shown in Table 1.

[0108] Table 1

[0109]

[0110] As can be seen from the test results in Table 1, both Example 1 and Example 2 achieved high separation factors and adsorption capacities, and the separation factors were the same for both, with only a small difference in adsorption capacity.

[0111] Example 1, with the same separation conditions as Comparative Examples 1 and 2, exhibited higher separation factors and adsorption capacities than both. This is because the graphene nanosheet-supported Fe3O4 material increased the contact area between the Fe3O4 nanoparticles and boric acid, enhancing the electronic conductivity of Fe3O4. Furthermore, the high enrichment performance of the graphene nanosheets increased the boric acid concentration around the Fe3O4 nanoparticles, resulting in a higher separation factor and adsorption capacity for the graphene nanosheet-supported Fe3O4 material. The provided method achieves separation under mild conditions with a high separation factor.

[0112] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A method for separating boron isotopes, characterized in that, Includes the following steps: A boric acid aqueous solution is mixed with a pH adjuster to adjust the pH of the solution to 6-8, and a sample to be separated is prepared. The sample to be separated contains enriched... 10 B(OH)4 of element B - ; The sample to be separated is contacted with a graphene-supported Fe3O4 composite material, allowing the graphene-supported Fe3O4 composite material to adsorb and enrich the sample. 10 B(OH)4 of element B - .

2. The method for separating boron isotopes according to claim 1, characterized in that, One or more of the following conditions must be met: (1) The concentration of boric acid in the boric acid aqueous solution is 0.1 mol / L to 1 mol / L; and (2) The pH adjuster includes one or both of sodium hydroxide and potassium hydroxide.

3. The method for separating boron isotopes according to claim 1, characterized in that, The ratio of boric acid in the graphene-supported Fe3O4 composite material and the boric acid aqueous solution is (0.01~0.5) g : (0.1~1) mol.

4. The method for separating boron isotopes according to claim 1, characterized in that, The preparation method of the graphene-supported Fe3O4 composite material includes the following steps: Graphene was dispersed in an aqueous solution of iron salts and subjected to hydrolysis under heating conditions, and the solid material was collected. The solid material was dried and calcined in an inert gas atmosphere to prepare the graphene-supported Fe3O4 composite material.

5. The method for separating boron isotopes according to claim 4, characterized in that, The ratio of graphene to iron salt is (30~100) mg: (0.005~0.01) mol.

6. The method for separating boron isotopes according to claim 4, characterized in that, One or both of the following conditions must be met: (1) The heating temperature is 70℃~90℃, and the heating time is 8h~16h; and (2) The calcination temperature is 500℃~650℃ and the calcination time is 3h~6h.

7. The method for separating boron isotopes according to claim 4, characterized in that, The iron salt includes one or more of ferric chloride, ferric nitrate, and ferric sulfate.

8. The method for separating boron isotopes according to any one of claims 1 to 7, characterized in that, The adsorption time is 0.5h to 6h.

9. The method for separating boron isotopes according to any one of claims 1 to 7, characterized in that, It also includes solid-liquid separation, in which the separated solids are contacted with an eluent to elute and enrich them. 10 B(OH)4 - It is separated from the graphene-supported Fe3O4 composite material.

10. The method for separating boron isotopes according to claim 9, characterized in that, One or more of the following conditions must be met: (1) The eluent comprises one or more of the following: an aqueous solution of acetic acid, an aqueous solution of hydrochloric acid, an aqueous solution of sulfuric acid, an aqueous solution of nitric acid, and an aqueous solution of phosphoric acid with a pH of 3 to 5; (2) The volume ratio of the eluent to the boric acid aqueous solution is (1~2):1; and (3) The washing time is 0.5h~6h.

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