Synergistic extraction system and extraction process for the separation of boron isotopes

Abstract

The present application relates to a synergistic extraction system for the separation of boron isotopes, comprising: (1) a compound of formula IA; (2) a compound of formula IIB and / or formula IIC; and optionally (3) a polar hydrophobic additive. Wherein, in formula IA, the hydroxyl group and the carboxyl group are ortho; R1, R2 are the same or different, linear or branched alkyl, alkoxy or phenyl functional groups with 1-20 carbon atoms; in formula IIB, X is a nitrogen atom or a phosphorus atom; R1, R2 and R3 are the same or different, linear or branched alkyl, alkoxy or phenyl functional groups with 3-20 carbon atoms; in formula IIC, X is a nitrogen atom or a phosphorus atom, Y is any one of halide, HSO4 ‑ , RC02 ‑ , and OH ‑ , R1-R4 are the same or different, linear or branched alkyl, alkoxy or phenyl functional groups with 1-20 carbon atoms. The present application further relates to a multi-stage countercurrent extraction process using the synergistic extraction system.

Description

Technical Field

[0001] This invention relates to isotope separation in the chemical industry, to a synergistic extraction system for extracting and separating boron isotopes, and further to a multi-stage countercurrent extraction process for enriching boron isotopes using this synergistic extraction system. Background Technology

[0002] Boron has two stable isotopes. 10 B and 11 B, with natural abundances of 19.8% and 80.2%, respectively. 10 Due to its large thermal neutron absorption cross section (3837 bar), B has a strong neutron absorption capacity and is widely used in the manufacture of neutron counters, nuclear reactor control rods, neutron absorbers, and in the treatment of tumors. 11 B has a small thermal neutron absorption cross section (0.005 bar) and excellent neutron transmission capability, thus it has important applications in radiation-resistant materials where high neutron transmission capability is required. Because... 10 B and 11 B has diametrically opposed neutron absorption and transmission capabilities; to utilize their respective properties, they must be separated, but... 10 B and 11 B has extremely similar chemical properties, making separation extremely difficult.

[0003] Currently, the industrialized boron isotope separation technology is the boron trifluoride (BF3)-anisole chemical exchange distillation method. Although this method... 10 B and 11 The single-stage separation coefficient (α) of B can reach about 1.03, but the starting material BF3 used is highly corrosive to the equipment, and the enrichment abundance is greater than 95%. 10 B requires hundreds of exchange processes, resulting in complex technology, high equipment requirements, and poor overall economic efficiency. Furthermore, it has been found that commercially available basic anion exchange resins (such as CG-400I and Diaion PA312) and boron-specific resins (such as Diaion CRB02 and IRA743) can also effectively separate [the ion exchange process]. 10 B and 11 B. These resins can adsorb the borate ions formed by the reaction of the hydroxyl groups they release with boric acid. 10 B and 11 Borate (B) undergoes isotopic exchange between boric acid and borate ions. This method yields α values ​​comparable to chemical distillation and is more environmentally friendly due to the use of boric acid, resulting in lower equipment corrosion. However, the difficulties in resin regeneration, low yield, and low mechanical strength severely limit its application in industrial isotopic separation.

[0004] Solvent extraction is one of the most commonly used and efficient separation methods in hydrometallurgy and pharmaceutical separation. Based on the different affinities of extractants for different target ions or molecules and the design of the process, solvent extraction has achieved the separation of many complex mixtures that are extremely difficult to separate, such as the efficient separation of rare earth elements and chiral drugs. In contrast, the separation of isotopes of a single element using solvent extraction is based on chemical exchange reactions. Due to its advantages such as simple process, strong continuous operation, and low pollution, solvent extraction shows great potential to replace existing mature isotope separation technologies in the future. Currently, research on the separation of boron isotopes using solvent extraction is still in its early stages. CN116531942A discloses an extractant, extraction system, and its application for the extraction and separation of boron isotopes, but its main characteristic is that the extractant is a polyhydroxy compound with ortho- or meta-hydroxyl structures. Under the "dual carbon" background, stricter environmental standards have placed higher demands on the production processes of high-abundance boron isotopes, requiring greener and more environmentally friendly processes to replace the reactive distillation separation process using BF3 as a raw material.

[0005] To address the problems of existing technologies, this invention provides a novel synergistic extraction system based on boric acid extraction. This system possesses a high single-stage separation coefficient and is used in multi-stage countercurrent extraction processes of boric acid for boron isotope separation, achieving high abundance and high yield. 10 B and 11 Product B. Summary of the Invention

[0006] The purpose of this invention is to provide a synergistic extraction system for separating boron isotopes using solvent extraction, and further to provide a process for enriching boron isotopes through multi-stage countercurrent extraction using the said synergistic extraction system. This invention achieves its purpose through the following technical solutions.

[0007] On one hand, the present invention provides a synergistic extraction system for the extraction and separation of boron isotopes, comprising a compound of formula IA, a compound of formula IIB and / or IIC, and optionally a polar hydrophobic additive. Specifically, when used for extraction, the compound of formula IIB and / or IIC is prepared as an organic phase with a concentration of 0.05 mol / L to 1 mol / L; the compound of formula IA is dissolved in either the organic phase or the aqueous phase (i.e., the feed solution) depending on its hydrophobicity, i.e., when the compound of formula IA is hydrophobic, it dissolves in the organic phase, and when it is hydrophilic, it dissolves in the aqueous phase; the concentration of the compound of formula IA in the organic phase or the aqueous phase is 0.05 mol / L to 2 mol / L; the additive content is 0 vol% to 30 vol%, based on the total volume of the organic phase prepared for extraction.

[0008]

[0009] In formula IA, the hydroxyl group and the carboxyl group are in the ortho position; R1 and R2 can be the same or different, and are straight-chain or branched alkyl, alkoxy or phenyl functional groups with 1 to 20 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 7 to 20 carbon atoms, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms.

[0010] In Formula IIB, X is a nitrogen atom or a phosphorus atom; R1, R2, and R3 may be the same or different, and are straight-chain or branched alkyl, alkoxy, or phenyl functional groups with 3 to 20 carbon atoms, preferably 7-20 carbon atoms, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. In Formula IIC, X is a nitrogen atom or a phosphorus atom, and Y is a halide anion, HSO4, etc. - RCO2 - and OH - Any one of them, R1-R4 can be the same or different, and are straight-chain or branched alkyl, alkoxy or phenyl functional groups with 1 to 20 carbon atoms, preferably with 7 to 20 carbon atoms, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms.

[0011] Compounds of formula IA are compounds having ortho-hydroxy and carboxyl groups, examples of which include, but are not limited to: DL-2-hydroxybutyric acid, 1-hydroxycyclohexylcarboxylic acid, 3-phenyllactic acid, 2-hydroxy-3-(m-tolyl)propionic acid, 2-hydroxy-3-methylpropionic acid, 2-hydroxy-4-phenylbutyric acid, 2-hydroxy-5-phenylpentanoic acid, 7-hydroxy-7-phenylheptanoic acid, 2-hydroxydecanoic acid, 2-hydroxynonanoic acid, 2-hydroxyisohexanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxyeicosanoic acid, and 2-hydroxydocanoic acid.

[0012] Compounds of formulas IIB and IIC can be used in any proportion. Examples of compound IIB include, but are not limited to, one or more combinations of trihexylamine, trioctylamine, trinonylamine, tridecylamine, dioctylhexylamine, dioctylnonylamine, didecylnonylamine, dihexyldodecylamine, trioctyl phosphite, trioleyl phosphate, triisodecyl phosphite, and tridecyl phosphite. Examples of compounds of formula IIC include, but are not limited to, one or more combinations of methyltrioctylammonium chloride, propyltrioctylammonium chloride, methyltrialkylammonium chloride, trinonylmethylammonium chloride, benzyltrioctylammonium chloride, tetradecylammonium bromide, tetran-n-octylammonium iodide, tetraoctadecylammonium hydroxide, tetrabutylphosphine chloride, tetraphenylphosphine chloride, trihexyl(tetradecyl)phosphine chloride, n-octyltributylphosphine chloride, and hexadecyltributylphosphine chloride.

[0013] The polar hydrophobic additive is selected from one, two, or more of alcohols, ketones, ethers, and esters. The alcohol can be selected from octanol, decanol, dodecyl alcohol, etc.; the ketone is, for example, 4-methyl-2-pentanone (MIBK), diisobutyl ketone (DIBK), etc.; the ether is, for example, dipentyl ether, dihexyl ether, etc.; and the ester is, for example, heptyl acetate, butyl benzoate, etc. The polar hydrophobic additive helps improve the solubility and phase separation effect of organic matter.

[0014] On the other hand, the present invention further provides a multi-stage countercurrent extraction process for extracting boric acid solution to separate boron isotopes, wherein the extraction is performed using the synergistic extraction system according to the present invention, comprising the following steps:

[0015] (1) Preparation of organic phase: Dilute the compounds of formula IIB and / or IIC with a diluent, optionally add additives, and stir and mix at room temperature to form an organic phase, so that the total concentration of the compounds of formula IIB and / or IIC is 0.05 mol / L to 1 mol / L.

[0016] (2) Preparation of aqueous phase: Dissolve solid boric acid in water at room temperature to make the boric acid concentration 0.05 mol / L to 0.7 mol / L;

[0017] (3) Based on the hydrophobicity of the compound of formula IA, under normal temperature conditions, stir and dissolve it in an organic phase or an aqueous phase so that the concentration of the compound of formula IA in the aqueous phase or organic phase is 0.05 mol / L to 2 mol / L.

[0018] (4) Preparation of back-extraction solution: Dissolve the alkaline solute in water at room temperature to prepare back-extraction solution, and adjust its concentration to 0.5 mol / L to 2 mol / L;

[0019] (5) Connect M mixing and clarifying tanks or centrifugal extractors in series to form a multi-stage countercurrent extraction device;

[0020] (6) The organic phase and the aqueous phase are controlled to flow continuously in counter-current order, and the organic phase and the back-extraction solution are controlled to flow continuously in counter-current order. A solution containing [a specific ingredient] is obtained from the aqueous phase outlet. 11 The product containing B isotopes was obtained from the back-extraction liquid outlet. 10 Products containing B isotopes.

[0021] The boron concentration, C0, at the aqueous phase outlet and the stripping solution outlet can be obtained using inductively coupled plasma atomic absorption spectrometry (ICP-OES). 出水 With C 反出 The aqueous phase outlet and the back-extraction solution outlet were measured using a multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS). 11 B and 10 B abundance value, i.e., a 11B With a 10B The boric acid stock solution was determined by MC-ICP-MS. 11 B and 10 The abundance values ​​of B, namely 80.045% and 19.995%, can be used to calculate the yield using the following formula:

[0022]

[0023]

[0024] Where ψ is rich 10 B or 11 Yield of compound B, C 原液 (mol / L) represents the concentration of the boric acid stock solution, f 反萃液 (ml / min) and f 原液 (ml / min) represent the flow rates of the back-extraction solution and the original solution, respectively.

[0025] In step (1), the diluent comprises: kerosene, octanone, chloroform, carbon tetrachloride, toluene, xylene, diethylbenzene, bromobenzene, anisole, nitromethane, 2-methylcyclohexanone, methyl isobutyl ketone, chlorobenzene, dichlorobenzene, trichlorobenzene, diphenyl ether, or combinations thereof. The additive content is 0 vol%-30 vol%, based on the total volume of the organic phase.

[0026] In step (4), the alkaline solute includes sodium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, or a combination thereof. The concentration of the back-extraction solution is 0.5 mol / L to 2 mol / L.

[0027] In step (5), the number of mixing and clarification tanks or centrifugal extractors is 10 ≤ M ≤ 2000. The multi-stage countercurrent extraction device includes an extraction stage and a back-extraction stage, wherein the number of back-extraction stages is 2 to 100.

[0028] In step (6), the flow rate ratio of the organic phase to the aqueous phase is 0.5 to 5, and the flow rate ratio of the organic phase to the back-extraction solution is 0.5 to 10.

[0029] According to the multi-stage countercurrent extraction process of the present invention, by adjusting the concentration ratio between the components of the extractant, the boric acid concentration, the ratio between the organic phase and the aqueous phase, and the number of extraction stages, a rich extractant can be obtained. 11 B isotope products (isotopic abundance between 84% and 99.99%); rich in... 10 B isotope products (isotope abundance between 30% and 99.99%).

[0030] The present invention further relates to the use of the synergistic extraction system according to the present invention for extracting boric acid solutions to separate boron isotopes, for example, it can be used as a thermal neutron absorber and neutron moderator in the nuclear industry; neutron protective clothing, nuclear protective clothing, neutron protective guns and nuclear submarines in the military industry; electronic specialty gases in the semiconductor industry, etc.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) The compound of formula IA in the extraction system of this invention is a compound having ortho-hydroxy and carboxyl groups, which can complex with boric acid to form an anionic complex with boron atoms bonded to four oxygen atoms. This complex is then extracted into the organic phase by compounds of formula IIB and / or IIC, with isotopes exchanging between the boric acid and the anionic complex. In particular, the extraction system of this invention has a high single-stage separation factor, achieving a single-stage separation factor of 1.04 for boron isotopes. Furthermore, it is inexpensive and the raw materials are readily available.

[0033] (2) In the multi-stage countercurrent extraction process of this invention, boric acid is used instead of BF3 as the target extraction material, which is more environmentally friendly, reduces the harm to the health of operators, and yields a higher concentration of boric acid. 10 B or 11 Product B boasts an isotopic abundance of up to 99.99%, completely replacing the existing BF3-anisole chemical exchange distillation method and meeting market demand for products with varying boron isotopic abundances. Furthermore, the equipment used is simple, and the extractant is recyclable, significantly reducing production costs. Detailed Implementation

[0034] The present invention will now be described in detail with reference to embodiments. These embodiments are illustrative and do not imply limitation of the invention. The reagents and apparatus used in the embodiments of the present invention are all commonly used in the art.

[0035] Example 1

[0036] 2-Hydroxydodecanoic acid and trioctylamine were dissolved in p-xylene as the organic phase, with concentrations of 0.5 mol / L for 2-hydroxydodecanoic acid and 0.5 mol / L for trioctylamine. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the stripping solution. A 55-stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 5 stages being the stripping stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with a stirring speed set to 800 rpm / min. The mixing and clarifying tank was filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and stripping solution were maintained at 15 mL / min:15 mL / min:15 mL / min, controlled by a peristaltic pump. After the apparatus had run for 12 hours and the boron concentrations at each stage had stabilized, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the stripping solution outlet, respectively. 11 B and 10 Product B had abundances of 86.72% and 26.32%, respectively, and C was measured. 出水 The value is 0.0115 mol / L. Rich 11 The yield of compound B was 2.493% (calculated according to formulas (1) and (2)).

[0037] Example 2

[0038] 2-Hydroxydodecanoic acid and trinonylamine were dissolved in p-xylene as the organic phase, with concentrations of 0.4 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the stripping solution. A 55-stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 5 stages being the stripping stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with a stirring speed set to 800 rpm / min. 250 mL of aqueous phase and 250 mL of organic phase were filled into the mixing and clarifying tank, respectively. The flow rates of the organic phase, aqueous phase, and stripping solution were maintained at 15 mL / min:15 mL / min:15 mL / min, controlled by a peristaltic pump. After the apparatus ran for 12 hours and the boron concentration at each stage stabilized, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the stripping solution outlet, respectively. 11 B and 10 Product B had abundances of 84.36% and 23.96%, respectively, and C was measured. 出水 The value is 0.01516 mol / L. Rich 11 The yield of compound B was 3.196% (calculated according to formulas (1) and (2)).

[0039] Example 3

[0040] 3-Phenylonic acid and methyltrioctylammonium chloride were dissolved in kerosene as the organic phase, with concentrations of 0.4 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the stripping solution. A countercurrent extraction apparatus consisting of 55 stages, each with a 500 mL mixing and clarifying tank connected in series, was constructed, with 5 stages being the stripping stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with a stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and stripping solution were maintained at 20 mL / min:15 mL / min:20 mL / min, controlled by a peristaltic pump. After the apparatus had run for 12 hours and the boron concentrations at each stage had stabilized, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the stripping solution outlet, respectively. 11 B and 10 Product B had abundances of 85.64% and 25.24%, respectively, and C was measured. 出水 The value is 0.01261 ​​mol / L. Rich 11 The yield of compound B was 2.699% (calculated according to formulas (1) and (2)).

[0041] Example 4

[0042] 2-Hydroxydodecanoic acid and methyltrioctylammonium chloride were dissolved in p-xylene as the organic phase, with concentrations of 0.4 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the stripping solution. A 210-stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being the stripping stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with a stirring speed set to 800 rpm / min. 250 mL of aqueous phase and 250 mL of organic phase were filled into the mixing and clarifying tank, respectively. The flow rates of the organic phase, aqueous phase, and stripping solution were maintained at 15 mL / min:15 mL / min:15 mL / min, controlled by a peristaltic pump. After the apparatus ran for 12 hours and the boron concentration at each stage stabilized, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the stripping solution outlet, respectively. 11 B and 10 Product B had abundances of 96.76% and 64.52%, respectively, and C was measured. 出水 The value was 0.004769 mol / L. Rich 11 The yield of compound B was 1.153% (calculated according to formulas (1) and (2)).

[0043] Example 5

[0044] 2-Hydroxydodecanoic acid and trihexylamine were dissolved in p-xylene as the organic phase, with concentrations of 0.5 mol / L for 2-hydroxydodecanoic acid and 0.5 mol / L for trihexylamine. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the stripping solution. A 510-stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being the stripping stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with a stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and stripping solution were maintained at 20 mL / min:15 mL / min:20 mL / min. After the apparatus had run for 12 hours and the boron concentrations at each stage had stabilized, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the stripping solution outlet, respectively. 11 B and 10 Product B had abundances of 99.83% and 97.30%, respectively, and C was measured. 出水 The value is 0.004037 mol / L. Rich 11 The yield of compound B was 1.007% (calculated according to formulas (1) and (2)).

[0045] Example 6

[0046] 2-Hydroxydodecanoic acid and tridecylamine were dissolved in p-xylene as the organic phase, and 5 vol% dodecyl alcohol was added to the organic phase. The concentrations of 2-hydroxydodecanoic acid and tridecylamine were set to 0.5 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the back-extraction solution. A 5-10 stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being the back-extraction stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with the stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and back-extraction solution were maintained at 20 mL / min:15 mL / min:20 mL / min. After the apparatus ran for 12 hours and the boron concentration at each stage reached stability, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the back-extraction solution outlet, respectively. 11 B and 10 Product B had abundances of 99.96% and 97.87%, respectively, and C was measured. 出水 The value is 0.004023 mol / L. Rich 11 The yield of compound B was 1.0049% (calculated according to formulas (1) and (2)).

[0047] Example 7

[0048] 2-Hydroxydodecanoic acid and trioctylamine were dissolved in p-xylene as the organic phase, and 5 vol% dodecyl alcohol was added to the organic phase. The concentrations of 2-hydroxydodecanoic acid and trioctylamine were set to 0.1 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the back-extraction solution. A 5-10 stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being the back-extraction stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with the stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and back-extraction solution were maintained at 20 mL / min:15 mL / min:20 mL / min. After the apparatus ran for 12 hours and the boron concentration at each stage reached stability, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the back-extraction solution outlet, respectively. 11 B and 10 Product B had abundances of 71.34% and 56.97%, respectively, and C was measured. 出水 The value was 0.03712 mol / L. Rich 11 The yield of compound B was 6.617% (calculated according to formulas (1) and (2)).

[0049] Example 8

[0050] 2-Hydroxydodecanoic acid and trioctylamine were dissolved in p-xylene as the organic phase, and 5 vol% dodecyl alcohol was added to the organic phase. The concentrations of 2-hydroxydodecanoic acid and trioctylamine were set to 0.5 mol / L and 0.2 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the back-extraction solution. A 5-10 stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being back-extraction stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with the stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and back-extraction solution were maintained at 20 mL / min:15 mL / min:20 mL / min. After the apparatus ran for 12 hours and the boron concentration at each stage reached stability, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the back-extraction solution outlet, respectively. 11 B and 10 Product B had abundances of 59.86% and 51.37%, respectively, and C was measured. 出水 The value was 0.03842 mol / L. Rich 11 The yield of compound B was 5.747% (calculated according to formulas (1) and (2)).

[0051] Example 9

[0052] DL-2-hydroxybutyric acid and trioctylamine were dissolved in p-xylene as the organic phase, and 5 vol% dodecyl alcohol was added to the organic phase. The concentrations of 2-hydroxybutyric acid and trioctylamine were set to 0.1 mol / L and 0.5 mol / L, respectively. A 0.5 mol / L boric acid solution was prepared as the aqueous phase, and a 1 mol / L sodium hydroxide solution was prepared as the back-extraction solution. A 510-stage countercurrent extraction apparatus consisting of 500 mL mixing and clarifying tanks connected in series was constructed, with 10 stages being the back-extraction stages. For each mixing and clarifying tank, a brushless DC motor stirrer was installed in the mixing chamber, with the stirring speed set to 800 rpm / min. The tanks were filled with 250 mL of aqueous phase and 250 mL of organic phase, respectively. The flow rates of the organic phase, aqueous phase, and back-extraction solution were maintained at 20 mL / min:15 mL / min:20 mL / min. After the apparatus ran for 12 hours and the boron concentration at each stage reached stability, it was run for another 24 hours. Rich boron extracts were obtained from the aqueous phase outlet and the back-extraction solution outlet, respectively. 11 B and 10 Product B had abundances of 53.88% and 46.16%, respectively, and C was measured. 出水 The value is 0.05652 mol / L. Rich 11 The yield of compound B was 7.610% (calculated according to formulas (1) and (2)).

[0053] As can be seen from the above embodiments, using the synergistic extraction system of the present invention, and through the multi-stage countercurrent extraction process of the present invention, excellent enrichment was obtained under various parameter conditions taught therein. 10 B and 11 The yield and abundance of compound B products; the highest abundance of the products can exceed 99%, demonstrating extremely broad application prospects.

Claims

1. A synergistic extraction system for the extraction and separation of boron isotopes, comprising: a compound of formula IA, a compound of formula IIB and / or IIC, and optionally a polar hydrophobic additive; ； in, In formula IA, the hydroxyl group and the carboxyl group are in the ortho position; R1 and R2 are the same or different, and are straight-chain or branched alkyl, alkoxy or phenyl functional groups with 1 to 20 carbon atoms. In formula IIB, X is a nitrogen atom or a phosphorus atom; R1, R2 and R3 are the same or different, and are straight-chain or branched alkyl, alkoxy or phenyl functional groups with 3 to 20 carbon atoms; In formula IIC, X is a nitrogen atom or a phosphorus atom, and Y is a halide anion or HSO4. ⁻ RCO2 ⁻ and OH ⁻ Any one of them, where R1–R4 are the same or different, and are straight-chain or branched alkyl, alkoxy or phenyl functional groups having 1 to 20 carbon atoms; The compounds of Formula IA are selected from one or more combinations of the following: DL-2-hydroxybutyric acid, 1-hydroxycyclohexylcarboxylic acid, 3-phenyllactic acid, 2-hydroxy-3-(m-tolyl)propionic acid, 2-hydroxy-3-methylpropionic acid, 2-hydroxy-4-phenylbutyric acid, 2-hydroxy-5-phenylpentanoic acid, 7-hydroxy-7-phenylheptanoic acid, 2-hydroxydecanoic acid, 2-hydroxynonanoic acid, 2-hydroxyisohexanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid, 2-hydroxyeicosanoic acid, and 2-hydroxydocanoic acid.

2. The synergistic extraction system according to claim 1, characterized in that: When used for extraction, the compounds of formula IIB and / or IIC are prepared as an organic phase with a concentration of 0.05 mol / L to 1 mol / L; the compounds of formula IA are dissolved in the organic or aqueous phase, depending on their hydrophobicity, with a concentration of 0.05 mol / L to 2 mol / L in the organic or aqueous phase; the additive content is 0 vol% to 30 vol%, based on the total volume of the organic phase.

3. The synergistic extraction system according to claim 1, characterized in that: The compounds of Formula IIB are selected from one or more combinations of: trihexylamine, trioctylamine, trinonylamine, tridecylamine, dioctylhexylamine, dioctylnonylamine, didecylnonylamine, dihexyldodecylamine, trioctyl phosphite, trioleyl phosphate, triisodecyl phosphite, and tridecyl phosphite; the compounds of Formula IIC are selected from one or more combinations of: methyltrioctylammonium chloride, propyltrioctylammonium chloride, methyltrialkylammonium chloride, trinonylmethylammonium chloride, benzyltrioctylammonium chloride, tetradecylammonium bromide, tetran-n-octylammonium iodide, tetraoctadecylammonium hydroxide, tetrabutylphosphine chloride, tetraphenylphosphine chloride, trihexyl(tetradecyl)phosphine chloride, n-octyltributylphosphine chloride, and hexadecyltributylphosphine chloride.

4. The synergistic extraction system according to claim 1, characterized in that: The polar hydrophobic additive is one or a mixture of two or more of alcohols, ketones, ethers, and esters; wherein the alcohol is selected from octanol, decanol, and dodecanol; the ketone is selected from 4-methyl-2-pentanone and diisobutyl ketone; the ether is selected from dipentyl ether and dihexyl ether; and the ester is selected from heptyl acetate and butyl benzoate.

5. A multi-stage countercurrent extraction process for extracting boric acid solution to separate boron isotopes, wherein the synergistic extraction system of any one of claims 1-4 is used, the process comprising the following steps: (1) Preparation of the organic phase: The compound of formula IIB and / or IIC is diluted with a diluent, and an additive is optionally added. The mixture is stirred and mixed at room temperature to form an organic phase, such that the concentration of the compound of formula IIB and / or IIC is 0.05 mol / L ~ 1 mol / L; wherein the additive is one or a mixture of two or more of alcohols, ketones, ethers, and esters; the alcohol is selected from octanol, decanol, and dodecanol; the ketone is selected from 4-methyl-2-pentanone and diisobutyl ketone; the ether is selected from dipentyl ether and dihexyl ether; the ester is selected from heptyl acetate and butyl benzoate. (2) Preparation of the aqueous phase: Dissolve solid boric acid in water at room temperature to make the boric acid concentration 0.05 mol / L ~ 0.7 mol / L; (3) Based on the hydrophobicity of the compound of formula IA in the synergistic extraction system, under normal temperature conditions, it is stirred and dissolved in the organic phase or aqueous phase so that the concentration of the compound of formula IA is 0.05 mol / L ~ 2 mol / L; (4) Preparation of back-extraction solution: Dissolve the alkaline solute in water at room temperature to prepare a back-extraction solution with a concentration of 0.5 mol / L ~ 2 mol / L; (5) Connect M mixing and clarification tanks or centrifugal extractors in series to form a multi-stage countercurrent extraction device; where 10 ≤ M ≤ 2000; (6) Control the continuous counter-current flow of the organic phase and the aqueous phase, and the continuous counter-current flow of the organic phase and the back-extraction solution, to obtain a solution containing [unclear text - possibly a substance or ingredient] from the aqueous phase outlet. 11 Product B, obtained from the back-extraction liquid outlet, contains... 10 B's product.

6. The multi-stage countercurrent extraction process according to claim 5, characterized in that: In step (1), compounds of formula IIB and IIC are used in any proportion.

7. The multi-stage countercurrent extraction process according to claim 5, characterized in that: In step (4), the alkaline substance is selected from sodium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, or a combination thereof.

8. The multi-stage countercurrent extraction process according to claim 5, characterized in that: In step (6), the flow rate ratio of the organic phase to the aqueous phase is 0.5 to 5, and the flow rate ratio of the organic phase to the back-extraction solution is 0.5 to 10.

9. Use of the synergistic extraction system according to any one of claims 1-4 for extracting boric acid solution to separate boron isotopes.

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