Device and method for extracting and separating boron isotope by coupling external electric field with liquid membrane

Abstract

The invention discloses a device for extracting and separating boron isotopes by coupling an external electric field with a liquid membrane, which comprises a depletion chamber, a liquid membrane chamber and an enrichment chamber which are arranged in sequence, an anode plate is arranged in the depletion chamber, a cathode plate is arranged in the enrichment chamber, the anode plate and the cathode plate are both connected with a direct current stabilized power supply, and temperature control units are arranged in the depletion chamber and the enrichment chamber. Mixing mechanisms are arranged on the dilution chamber and the enrichment chamber; the liquid membrane chamber comprises an anode supporting membrane, a cathode supporting membrane and a cavity between the anode supporting membrane and the cathode supporting membrane, and the cavity is used for containing an extraction organic phase; the invention also discloses a method for extracting and separating the boron isotope by coupling the external electric field with the liquid membrane. According to the device, the liquid membrane chamber is arranged between the depletion chamber and the enrichment chamber and is used for realizing non-equilibrium mass transfer by utilizing a liquid membrane structure, so that the synchronous operation of extraction-reverse extraction processes is realized, the process steps of extracting and separating boron isotopes are reduced, and the device is suitable for preparing enriched boric acid.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of isotope separation, and particularly relates to a device and method for separating boron isotopes by liquid membrane extraction coupled with an external electric field. BACKGROUND

[0002] In natural boron 10 The abundance of B is 19.8%, which is about 11 One fourth of B. 10 B has a very strong absorption capacity for thermal neutrons, and its absorption cross section can reach 3837 barns, which is much higher than the 752 barns of natural boron and 11 0.005 barns of B. Due to 10 The excellent neutron reaction performance of B, enriched 10 B has a relatively wide application in the fields of nuclear power, medicine, military equipment, electronics, etc. Among them, enriched boric acid is an indispensable key material in advanced nuclear power plants (especially pressurized water reactors) and safety facilities, which is crucial to the safe, reliable and economic operation of nuclear reactors. It is also an essential nuclear reaction carrier for boron neutron capture therapy technology, which has a significant effect on the treatment of local invasive tumors.

[0003] The existing large-scale industrial production method of enriched boric acid adopts the boron trifluoride-anisole chemical exchange rectification method, which realizes separation by multi-stage gas-liquid countercurrent exchange reaction in a packed exchange tower. The separation coefficient of this method is 1.02~1.04. The boron trifluoride used in this method is corrosive, and the water content in the system needs to be controlled to avoid hydrolysis reaction and equipment blockage. Moreover, the entire process needs to undergo boric acid-boron trifluoride-boric acid chemical conversion twice, which consumes a lot. Direct use of boric acid in aqueous solution for isotope separation can reduce cost and process difficulty. Ion resin exchange method uses boron-specific resin, and exchange action can adsorb 11 B on solid phase to realize separation, but this method has low separation coefficient, large consumption of regenerant, and cannot be operated continuously, and has not been applied in engineering.

[0004] The method of extracting and separating isotopes has been applied in lithium isotope separation for a long time. Crown ether extractants have good separation effect. In the aspect of separating boron isotopes, it is still in the initial research stage. For example, Chinese invention patent “Method for extracting and separating boron isotopes” (publication number CN117244402B) realizes isotope enrichment through multi-stage extraction-stripping circulation, which theoretically illustrates the feasibility of extraction method in separating boron isotopes, but has problems such as complicated continuous operation, difficulty in engineering scaling-up, and long process time. SUMMARY

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an apparatus for the extraction and separation of boron isotopes using an external electric field coupled liquid membrane. This apparatus, by setting a liquid membrane chamber between the depletion chamber and the enrichment chamber, utilizes the liquid membrane structure to achieve non-equilibrium mass transfer, enabling simultaneous extraction and back-extraction processes. This reduces the number of steps in the extraction and separation of boron isotopes and solves the problems of cumbersome operation and long processing time in the extraction and separation of boron isotopes.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: an apparatus for separating boron isotopes by external electric field coupling liquid membrane extraction, characterized in that it includes a depletion chamber, a liquid membrane chamber, and an enrichment chamber arranged sequentially, wherein an anode plate is provided in the depletion chamber, a cathode plate is provided in the enrichment chamber, both the anode plate and the cathode plate are connected to a DC regulated power supply, a temperature control unit is provided in both the depletion chamber and the enrichment chamber, and a mixing mechanism is provided on both the depletion chamber and the enrichment chamber; The liquid film chamber includes an anode support membrane, a cathode support membrane, and a cavity between the anode support membrane and the cathode support membrane, the cavity being used to hold the extracted organic phase.

[0007] The aforementioned apparatus for separating boron isotopes by external electric field coupled liquid membrane extraction is characterized in that the distance between the anode support membrane and the cathode support membrane is 5 mm to 15 mm.

[0008] The aforementioned device for extracting and separating boron isotopes using an external electric field coupled liquid membrane is characterized in that the anode support membrane and the cathode support membrane are both made of polyvinylidene fluoride, polypropylene, polyvinyl chloride, or polyurethane, with a thickness of 50μm to 150μm and a pore size of 0.1μm to 0.5μm.

[0009] The above-mentioned device for separating boron isotopes by external electric field coupling liquid membrane extraction is characterized in that the temperature control unit includes a heat exchanger, and the heat exchanger is connected to an external constant temperature circulator.

[0010] The above-mentioned device for extracting and separating boron isotopes by external electric field coupling liquid membrane is characterized in that the anode plate and the cathode plate are both titanium-based ruthenium dioxide coated electrodes, the distance between the anode plate and the cathode plate is 15cm~25cm, the anode plate is attached to the inner wall of the depletion chamber away from the liquid membrane chamber, and the cathode plate is attached to the inner wall of the enrichment chamber away from the liquid membrane chamber.

[0011] The aforementioned device for separating boron isotopes by external electric field coupling liquid membrane extraction is characterized in that the mixing mechanism includes a motor and a stirring paddle fixedly connected to the motor shaft, wherein the stirring paddle is an inclined blade paddle with an inclination angle of 30° to 60°.

[0012] The aforementioned apparatus for separating boron isotopes by external electric field coupled liquid membrane extraction is characterized in that the stirring paddle is a 3-bladed or 5-bladed inclined blade paddle.

[0013] The application also discloses a method for extracting and separating boron isotopes by using an external electric field coupled liquid membrane, characterized by using the device. Step one, adding boric acid feed liquid into the depletion chamber, adding stripping phase into the enrichment chamber, and adding extraction organic phase into the liquid membrane chamber, then starting the mixing mechanism, the direct current stabilized power supply and the temperature control unit, and starting the extraction and separation under the preset process conditions; Step two, after the extraction and separation in step one is completed, the depleted boric acid-10 is obtained in the depletion chamber, and the enriched boric acid-10 is obtained in the enrichment chamber.

[0014] The method has the following advantages. The stripping phase is a 0.01 mol / L dilute potassium chloride solution; and the extraction organic phase is composed of the following components with the following concentrations: 0.5 mol / L-0.8 mol / L trioctylamine, and the rest is o-xylene.

[0015] The boric acid feed liquid in the application uses potassium chloride as a conductive enhancer, and o-xylene is used as a diluent in the extraction organic phase.

[0016] The method has the following advantages.

[0017] The method has the following advantages. 1. The liquid membrane chamber is arranged between the depletion chamber and the enrichment chamber, which is used to realize non-equilibrium mass transfer by using the liquid membrane structure, realize the synchronous performance of the extraction-stripping process, and reduce the process steps of the extraction and separation of boron isotopes.

[0018] 2. The anode plate and the cathode plate are arranged in the depletion chamber and the enrichment chamber respectively, and the anode plate and the cathode plate are connected with the direct current stabilized power supply, which uses the electric field to strengthen the ion migration and greatly reduces the equilibrium time.

[0019] 3. This invention reduces equipment corrosion and environmental risks by replacing corrosive boron trifluoride with boric acid aqueous solution; and by controlling process parameters, it is applicable to working conditions where the boric acid concentration varies in the range of 0.1 mol / L to 1.0 mol / L, and achieves a single-stage separation factor α > 1.01.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the device for separating boron isotopes by external electric field coupling liquid membrane extraction according to the present invention.

[0022] Explanation of reference numerals in the attached figures: 1—Leaning chamber; 2—Liquid film chamber; 201—Anode support membrane; 202—Cathode support membrane; 3—Enrichment chamber; 4—Anode plate; 5—Cathode plate; 6—Temperature control unit; 7—Mixing mechanism; 701—Motor; 702—Agitator. Detailed Implementation

[0023] Example 1 like Figure 1 As shown, the device in this embodiment includes a depletion chamber 1, a liquid film chamber 2, and an enrichment chamber 3 arranged in sequence. An anode plate 4 is provided in the depletion chamber 1, and a cathode plate 5 is provided in the enrichment chamber 3. Both the anode plate 4 and the cathode plate 5 are connected to a DC regulated power supply. A temperature control unit 6 is provided in both the depletion chamber 1 and the enrichment chamber 3. A mixing mechanism 7 is provided on both the depletion chamber 1 and the enrichment chamber 3. The liquid film chamber 2 includes an anode support membrane 201, a cathode support membrane 202, and a cavity between the anode support membrane 201 and the cathode support membrane 202, the cavity being used to hold the extracted organic phase.

[0024] In practical use, this embodiment sequentially sets up a depletion chamber 1, a liquid film chamber 2, and an enrichment chamber 3. An anode plate 4 and a cathode plate 5 are respectively installed in the depletion chamber 1 and the enrichment chamber 3, and the anode plate 4 and cathode plate 5 are electrically connected to a DC regulated power supply. Boron isotope separation is achieved by using an external electric field coupled to the liquid film extraction process. A temperature control unit 6 is installed in the depletion chamber 1 and the enrichment chamber 3 to stabilize the temperature of the depletion chamber 1 at 20℃~25℃ and the temperature of the enrichment chamber 3 at 40℃~45℃. This temperature is beneficial to the back-extraction process and can improve back-extraction efficiency. A mixing mechanism 7 is installed to drive the liquid flow in the depletion chamber 1 and the enrichment chamber 3, accelerating ion diffusion. The liquid film chamber 2 is formed by the anode support membrane 201, the cathode support membrane 202, and the extracted organic phase. The support membrane separates the organic phase and the aqueous phase, avoiding phase entrainment. In this embodiment, the depletion chamber 1, the liquid film chamber 2, and the enrichment chamber 3 are all equipped with sealable inlets and outlets.

[0025] Further, as shown in Figure 1 In the embodiment, the distance between the anode support film 201 and the cathode support film 202 is 5mm-15mm.

[0026] In actual use, in the embodiment, the distance between the anode support film 201 and the cathode support film 202 is controlled to control the thickness of the extraction organic phase, so as to avoid that the thickness of the extraction organic phase is too thick, which causes mass transfer resistance and extraction efficiency reduction, and avoid that the thickness is too small, which causes the extraction organic phase to be discontinuous and the extraction efficiency to be reduced due to the influence of surface tension.

[0027] Further, as shown in Figure 1 In the embodiment, the material of the anode support film 201 and the cathode support film 202 is selected from polyvinylidene fluoride, polypropylene, polyvinyl chloride, and polyurethane, and the thickness is 50μ-150μm and the pore size is 0.1μ-0.5μm.

[0028] In actual use, in the embodiment, the material of the anode support film 201 and the cathode support film 202 is selected to be a hydrophobic material, which can ensure that the organic phase in the film does not flow out; by controlling the thickness of the support film, it can avoid that the thickness is too large, which causes large mass transfer resistance and efficiency reduction, and the thickness is too small, which causes insufficient support; by controlling the pore size, it can reduce the loss of organic phase while ensuring the efficiency.

[0029] Further, as shown in Figure 1 In the embodiment, the temperature control unit 6 includes a heat exchanger, and the heat exchanger is connected with an external constant temperature circulator.

[0030] In actual use, in the embodiment, the heat exchanger is laid on the bottom surface of the inner cavity of the depletion chamber 1 and the enrichment chamber 3, and the external constant temperature circulator and the heat exchanger are used to realize accurate temperature control and efficient heat exchange of the depletion chamber 1 and the enrichment chamber 3.

[0031] Further, as shown in Figure 1 In the embodiment, the anode plate 4 and the cathode plate 5 are titanium-based ruthenium dioxide coated electrodes, the distance between the anode plate 4 and the cathode plate 5 is 15cm-25cm, the anode plate 4 is attached to the inner wall of the end of the depletion chamber 1 away from the liquid film chamber 2, and the cathode plate 5 is attached to the inner wall of the end of the enrichment chamber 3 away from the liquid film chamber 2.

[0032] In actual use, in this embodiment, ruthenium dioxide coated titanium electrodes are selected as the cathode plate 5 and the anode plate 4. This electrode has a high current efficiency and corrosion resistance at the same time. By controlling the distance between the anode plate 4 and the cathode plate 5 to control the electric field strength, it is avoided that too large a distance will reduce the electric field strength and efficiency, and it is also avoided that too small a distance will cause electrolysis of water. By fitting the anode plate 4 to the inner wall of the end of the depletion chamber 1 far from the liquid film chamber 2, and fitting the cathode plate 5 to the inner wall of the end of the enrichment chamber 3 far from the liquid film chamber 2, all the liquids in the depletion chamber 1 and the enrichment chamber 3 are located between the anode plate 4 and the cathode plate 5, so that all the liquids can be extracted.

[0033] Further, as Figure 1 shown, in this embodiment, the mixing mechanism 7 includes a motor 701 and a stirring paddle 702 fixedly connected to the output shaft of the motor 701. The stirring paddle 702 is an inclined blade paddle with an inclination angle of 30° to 60°.

[0034] In actual use, in this embodiment, by setting the stirring paddle 702 and setting the motor 701 to provide power for stirring, and setting the stirring paddle 702 as an inclined blade paddle with an inclination angle of 30° to 60°, which is used to drive the liquid to flow parallel to the surface of the anode support membrane 201 or the cathode support membrane 202, it can improve the diffusion speed on both sides of the support membrane and accelerate the extraction and back-extraction processes. In this embodiment, the two motors 701 are respectively fixedly connected to the tops of the depletion chamber 1 and the enrichment chamber 3, and the stirring paddles 702 respectively extend into the inner cavities of the depletion chamber 1 and the enrichment chamber 3.

[0035] Further, as Figure 1 shown, in this embodiment, the inclined blade paddle is a 3-blade inclined blade paddle or a 5-blade inclined blade paddle.

[0036] In actual use, in this embodiment, by setting the number of blades of the inclined blade paddle, the inclined blade paddle forms a parallel flow at a specified rotational speed, and at the same time does not violently agitate the liquid to form a vortex.

[0037] Embodiment 2 This embodiment uses the device in Embodiment 1 to extract and separate boron isotopes. Among them, the anode support membrane 201 is made of polypropylene (PP) membrane with a thickness of 50 μm and a pore size of  0.2 μm; the cathode support membrane 202 is made of polyvinylidene fluoride (PVDF) membrane with a thickness of 50 μm and a pore size of  0.1 μm; the membrane distance between the cathode support membrane  202 and the anode support membrane 201 is 5 mm, and the distance between the anode plate 4 and the cathode plate 5 is 15 cm; the stirring paddle 702 is a 3-blade inclined blade paddle with an inclination angle of 60°; the method for extracting and separating boron isotopes includes the following steps: Step one, add boric acid solution in the depletion chamber 1, add stripping phase in the enrichment chamber 3, and add extraction organic phase in the liquid membrane chamber 2; the boric acid concentration in the boric acid solution is 0.1 mol / L, the 2,3-dihydroxybutanedioic acid is 0.15 mol / L, and the potassium chloride concentration is 0.03 mol / L; the extraction organic phase includes 0.5 mol / L trioctylamine (TOA), and the rest is o-xylene diluent; the stripping phase is a dilute potassium chloride solution with a concentration of 0.01 mol / L; Then start the mixing mechanism 7, the direct current stabilized power supply and the temperature control unit 6, and start the extraction separation under the preset process conditions for 2 hours; the preset process conditions are that the working temperature of the depletion chamber 1 is 20°C, the working temperature of the enrichment chamber 3 is 45°C, the voltage of the direct current stabilized power supply is 5V, and the stirring speed of the mixing mechanism 7 is 120 rpm; Step two, after the extraction separation in step one is completed, the depleted boron-10 acid is obtained in the depletion chamber 1, and the enriched boron-10 acid is obtained in the enrichment chamber 3.

[0038] After inspection, the boric acid concentration in the enrichment chamber 3 of the embodiment is 0.125 mol / L, 10 The B abundance is 20.10%, which is increased by 0.32% compared with the abundance before the extraction separation.

[0039] Example 3 The device in example 1 is used to separate boron isotopes in this embodiment, wherein the anode support membrane 201 and the cathode support membrane 202 are both polyvinyl chloride (PVC) membranes with a thickness of 100 μm and a pore size of 0.3 μm; the membrane spacing between the cathode support membrane 202 and the anode support membrane 201 is 10 mm, and the spacing between the anode plate 4 and the cathode plate 5 is 20 cm; the stirring paddle 702 is a 5-blade inclined paddle with an inclination angle of 40°; the method for separating boron isotopes includes the following steps: Step one, add boric acid solution in the depletion chamber 1, add stripping phase in the enrichment chamber 3, and add extraction organic phase in the liquid membrane chamber 2; the boric acid concentration in the boric acid solution is 0.5 mol / L, the 2,3-dihydroxybutanedioic acid is 0.75 mol / L, and the potassium chloride concentration is 0.02 mol / L; the extraction organic phase includes 0.6 mol / L trioctylamine (TOA), and the rest is o-xylene diluent; the stripping phase is a dilute potassium chloride solution with a concentration of 0.01 mol / L; Then start the mixing mechanism 7, the direct current stabilized power supply and the temperature control unit 6, and start the extraction separation under the preset process conditions for 1 hour; the preset process conditions are that the working temperature of the depletion chamber 1 is 25°C, the working temperature of the enrichment chamber 3 is 40°C, the voltage of the direct current stabilized power supply is 4V, and the stirring speed of the mixing mechanism 7 is 90 rpm; Step two, after the extraction separation in step one is completed, the depleted boron-10 acid is obtained in the depletion chamber 1, and the enriched boron-10 acid is obtained in the enrichment chamber 3.

[0040] The concentration of boric acid in the enrichment chamber 3 of the embodiment is 0.183 mol / L, 10 The abundance of B is 20.07%, which is increased by 0.29% compared with the abundance before extraction separation.

[0041] Embodiment 4 The device in embodiment 1 is used to extract and separate boron isotopes in the embodiment, wherein the anode support film 201 and the cathode support film 202 are both polyurethane (PU) films with a thickness of 150 μm and a pore size of 0.5 μm; the film spacing between the cathode support film 202 and the anode support film 201 is 15 mm, and the spacing between the anode plate 4 and the cathode plate 5 is 25 cm; the stirring paddle 702 is a 5-blade inclined paddle with an inclination angle of 30°; and the method for extracting and separating boron isotopes comprises the following steps: Step one, the boric acid feed liquid is added in the depletion chamber 1, the stripping phase is added in the enrichment chamber 3, and the extraction organic phase is added in the liquid membrane chamber 2; the concentration of boric acid in the boric acid feed liquid is 1.0 mol / L, the concentration of 2,3-dihydroxybutanedioic acid is 1.5 mol / L, and the concentration of potassium chloride is 0.01 mol / L; the extraction organic phase comprises tri-octylamine (TOA) with a concentration of 0.8 mol / L, and the rest is o-xylene diluent; and the stripping phase is a potassium chloride solution with a dilute concentration of 0.01 mol / L; Then the mixing mechanism 7, the direct current stabilized power supply and the temperature control unit 6 are started, and the extraction separation is started under the preset process conditions for 1.5 h; the preset process conditions are that the working temperature of the depletion chamber 1 is 25℃, the working temperature of the enrichment chamber 3 is 45℃, the voltage of the direct current stabilized power supply is 3V, and the stirring speed of the mixing mechanism 7 is 60 rpm; Step two, after the extraction separation in step one is completed, the depleted boric acid-10 is obtained in the depletion chamber 1, and the enriched boric acid-10 is obtained in the enrichment chamber 3.

[0042] The concentration of boric acid in the enrichment chamber 3 of the embodiment is 0.183 mol / L, 10 The abundance of B is 20.07%, which is increased by 0.29% compared with the abundance before extraction separation.

[0043] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent structural transformation made according to the technical essence of the present application to the above embodiment are still within the protection scope of the technical solution of the present application.

Claims

1. An apparatus for the separation of boron isotopes by means of an externally applied field-coupled liquid membrane extraction, characterized in that, The device comprises a depletion chamber (1), a liquid membrane chamber (2), and an enrichment chamber (3) arranged in sequence, the depletion chamber (1) is internally provided with an anode plate (4), the enrichment chamber (3) is internally provided with a cathode plate (5), the anode plate (4) and the cathode plate (5) are connected with a direct current stabilized power supply, the depletion chamber (1) and the enrichment chamber (3) are both provided with a temperature control unit (6), and the depletion chamber (1) and the enrichment chamber (3) are both provided with a mixing mechanism (7). The liquid membrane chamber (2) comprises an anode support membrane (201), a cathode support membrane (202), and a cavity between the anode support membrane (201) and the cathode support membrane (202), and the cavity is used for containing an extraction organic phase.

2. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 1, characterized in that, The distance between the anode support membrane (201) and the cathode support membrane (202) is 5mm-15mm.

3. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 1, characterized in that, The materials of the anode support membrane (201) and the cathode support membrane (202) are selected from polyvinylidene fluoride, polypropylene, polyvinyl chloride, and polyurethane, the thicknesses of the anode support membrane (201) and the cathode support membrane (202) are both 50μ-150μm, and the pore diameters of the anode support membrane (201) and the cathode support membrane (202) are both 0.1μ-0.5μm.

4. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 1, wherein, The temperature control unit (6) comprises a heat exchanger, and the heat exchanger is connected with an external constant-temperature circulator.

5. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 1, wherein, The anode plate (4) and the cathode plate (5) are both titanium-based ruthenium dioxide coating electrodes, the distance between the anode plate (4) and the cathode plate (5) is 15cm-25cm, the anode plate (4) is attached to the inner wall of the end of the depletion chamber (1) far from the liquid membrane chamber (2), and the cathode plate (5) is attached to the inner wall of the end of the enrichment chamber (3) far from the liquid membrane chamber (2).

6. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 1, wherein, The mixing mechanism (7) comprises a motor (701) and a stirring paddle (702) fixedly connected with the output shaft of the motor (701), and the stirring paddle (702) is an inclined-blade paddle with an inclination angle of 30°-60°.

7. The apparatus for separating boron isotopes by liquid membrane extraction with external electric field coupling according to claim 6, characterized in that, The inclined-blade paddle is a 3-blade inclined-blade paddle or a 5-blade inclined-blade paddle.

8. A method for the separation of boron isotopes by liquid membrane extraction with external electric field coupling, characterized in that, The method comprises the following steps by using the device according to any one of claims 1-7: Step one, boric acid feed liquid is added into the depletion chamber (1), stripping phase is added into the enrichment chamber (3), and extraction organic phase is added into the liquid membrane chamber (2), then the mixing mechanism (7), the direct current stabilized power supply, and the temperature control unit (6) are started, and extraction separation is started under preset process conditions; Step two, after the extraction separation in step one is completed, the depletion chamber (1) obtains depleted boric acid-10, and the enrichment chamber (3) obtains enriched boric acid-10.

9. The method for separating boron isotopes by external electric field coupled liquid membrane extraction according to claim 8, characterized in that, The boric acid feed liquid in step one is composed of the following components with the following concentrations: 0.1mol / L-1.0mol / L boric acid, 0.15mol / L-1.5mol / L 2,3-dihydroxybutanedioic acid, 0.01mol / L-0.03mol / L potassium chloride, and the rest is water; and the molar ratio of boric acid to 2,3-dihydroxybutanedioic acid is 1:1.5; The stripping phase is 0.01mol / L dilute potassium chloride solution; and the extraction organic phase is composed of the following components with the following concentrations: 0.5mol / L-0.8mol / L trioctylamine, and the rest is o-xylene.

10. The method for separating boron isotopes by external electric field coupled liquid membrane extraction according to claim 8, characterized in that, The preset process conditions in step one are that the temperature of the depletion chamber (1) is 20-25 ℃, the temperature of the enrichment chamber (3) is 40-45 ℃, the voltage of the direct-current stabilized power supply is 3-5 V, and the stirring speed is 60-120 rpm; and the time length of the extraction separation is 1-2 h.

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