CN113262638B - Separation and enrichment 7 Method for producing Li isotopes - Google Patents
Separation and enrichment 7 Method for producing Li isotopes Download PDFInfo
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Abstract
The invention discloses a separation and enrichment method 7 A method of Li isotopes. It comprises the following steps: uniformly mixing the ionic liquid, the diluent and the crown ether compound to form an extraction organic phase; mixing the extracted organic phase with lithium salt solution uniformly, and collecting the organic phase loaded with lithium after extraction; then, the anode, the cathode, the anolyte, the catholyte, the middle section bath solution, the first isolating membrane and the second isolating membrane together form an electromigration system; finally electrifying the electromigration system to obtain enrichment 7 Anode liquid and cathode liquid of Li; the middle section bath solution is the organic phase loaded with lithium, the first isolating film is arranged between the anode solution and the middle section bath solution, and the second isolating film is arranged between the middle section bath solution and the cathode solution. The multistage continuous separation process is simple to operate, continuous production can be realized, separation efficiency is greatly improved, and meanwhile, electromigration is carried out by using a three-stage method, so that ionization decomposition of an organic phase is avoided.
Description
Technical Field
The invention belongs to the technical field of lithium isotope separation and enrichment, and in particular relates to separation and enrichment 7 A method of Li isotopes.
Background
The high-abundance lithium isotope plays an important role in national economy and national defense safety. 99.9% or more of abundance 7 LiOH is an acidity regulator of pressurized water reactors, 7 LiBeF is the middle of the novel fused salt reactorSub-moderators. 30% -90% of abundance 6 Li is an indispensable raw material for fusion reactors and hydrogen bombs, and is also used for various neutron detectors. With the maturation of molten salt reactor and fusion reactor technology, the market pairs at home and abroad in the coming decades are as follows 7 Li and Li 6 The demand for Li will increase. While 7 Li and Li 6 The natural abundance of Li is 92.5% and 7.5%, respectively, and neither can be directly applied to the above fields, and it is necessary to carry out isotope separation.
The separation method of the lithium isotope mainly comprises a lithium amalgam method, a laser method, an extraction method, an electromagnetic method, an electrochemical method and the like. The lithium amalgam method is to use the difference between the abundance of isotopes of lithium amalgam and lithium ions in solution to realize isotope separation. The lithium amalgam method is the only method for industrialized production of lithium isotopes, which needs to use a large amount of mercury, has serious environmental hidden trouble and is phased out by European and American countries. The extraction method is to realize isotope separation by utilizing the difference of lithium isotope abundance in the aqueous phase and the organic phase, and the extraction level can reach hundreds or even thousands of levels in order to meet the requirement of the related application field on lithium isotope abundance due to extremely low separation factor of single-stage extraction, and a huge amount of liquid phase generated in the extraction process needs to be treated, so that the complicated operation process and extremely high production cost are caused to increase the difficulty of the application of the method.
The existing electrochemical methods can be divided into three types: aqueous solution method, molten salt method and organic solvent method. The aqueous solution method mainly utilizes the difference of electromigration rate of isotope ions in aqueous solution or a diaphragm to realize separation. The method has the advantages that the electrode reactions all occur in aqueous solution, the lithium ions generally do not undergo reduction reaction, continuous multistage separation is easy to realize, and the environmental protection pressure is low. However, due to the strong hydration of lithium ions in aqueous solutions, the difference in the ratio of the electromigration rates of the isotope ions is drastically reduced. The lithium isotope separation factor is generally low, and furthermore the process current utilization is low. The membrane of Tsuyoshi, etc. with ionic liquid injected in the middle layer of Tsuyoshi, etc. is used to separate lithium isotope in water solution by electrodialysis to obtain single separation factor up to 1.4, but the separation factor is along with the proportion of lithium ions migrating to cathodeThe separation factor is rapidly decreased when the separation factor is increased, and the separation effect disappears when the separation factor is close to 1% of the total lithium ions in the system. Crown ether functionalized polymer membranes were prepared by Tianjin university of industry, wang Mingxia, etc., and coupled with an electric field for lithium isotope separation. The molten salt method mainly utilizes the difference of electromigration rates of lithium isotope ions in high-temperature molten salt to realize separation. The method has the advantages of simple and reliable process, easy realization of multistage continuous separation, no water molecule complexation of lithium ions, high single-stage separation factor and high current utilization rate. However, the method has the problems of corrosion of high-temperature molten salt, chlorine gas, metallic lithium and the like, and has extremely high requirements on the material of the device. The method controls the cathode atmosphere to directly oxidize a small amount of generated metal lithium, so as to avoid corrosion of the metal lithium to the cathode. The mixed molten salt system of lithium chloride, lithium bromide, lithium nitrate and the like is developed in succession at university of tokyo industry in japan and the like, and LiNO 3 -NH 4 NO 3 The system obtains the optimal separation effect and obtains a small amount of 94.9 percent of abundance 6 Li sample. The spanish energy and environment research center Barrado et al propose an electrophoresis separation prototype based on lithium iodide fused salt, the device takes quartz as a shell, lithium lanthanum titanate solid ion superconductor as a film, and according to the prediction, a single 100-level continuous separation production line can annual yield 15kg of pure 6 Li products. The organic solvent method mainly utilizes the difference of partition ratio of lithium isotopes in solvent, cathode and anode materials to realize separation, and unlike the two methods in which lithium is in an ionic state, lithium ions in the organic solvent method can be partially reduced into metal or form intercalation compounds. The method has the advantages of being capable of being operated at room temperature, mild in reaction condition, basically the same in principle, materials and devices as the lithium ion battery, and the lithium ion battery industry can provide a good industrial foundation for the method. However, the product of the enrichment of the previous stage cannot be directly used as the raw material of the next stage, and multistage continuous separation is difficult to carry out; most of the organic solvents are carbonate electrolytes, are sensitive to air and water, and need to be closed.
The extraction method has extremely low separation factor of single-stage extraction, so that the extraction level can reach hundreds or even thousands in order to meet the requirement of the related application field on lithium isotope abundance, and huge amounts of aqueous phase and organic phase solutions with different lithium isotope abundance generated in the extraction process need to be treated. If the aqueous and organic phase solutions are not concentrated or stripped, they cannot be used in the next separation step. In addition, a certain amount of organic phase is dissolved in the aqueous phase. The reuse of the aqueous and organic phases is affected by the concentration, abundance and mutual dissolution of lithium ions, with great difficulty. Conventional electrochemical separation techniques: the direct electromigration in the aqueous solution has very low mass difference between lithium ions of the hydrated isotopes due to the existence of hydration, and the corresponding separation factor is also very low. The molten salt electrotransport technology has the problems of high-temperature molten salt, gas and metal lithium corrosion and the like, and has extremely high requirements on the device materials. The organic solution is separated by utilizing the distribution ratio difference of lithium isotopes in solvent, cathode and anode materials, and the product of the previous stage enrichment is mostly metallic lithium or solid compound of lithium, which can not be directly used as the raw material of the next stage, and is difficult to carry out multistage continuous separation; the organic solvents used are also mostly carbonate electrolytes, are sensitive to air and water and require a closed operation. In addition, most of the existing electrochemical separation technologies need batch sample injection, and have obvious isotope separation effects only at the forefront and the extreme ends of lithium ion migration flows, and most of the lithium ion migration flows in the middle have no separation effect, so that the current utilization efficiency is low.
Disclosure of Invention
The main purpose of the invention is to provide a separation and enrichment method 7 The Li isotope method overcomes the defects of the prior art.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention comprises the following steps:
the embodiment of the invention provides a separation and enrichment method 7 A method of Li isotope, comprising:
(1) Uniformly mixing the ionic liquid, the diluent and the crown ether compound to form an extraction organic phase;
(2) Uniformly mixing the extracted organic phase with a lithium salt solution, and collecting an organic phase loaded with lithium after extraction;
(3) The anode, the cathode, the anolyte, the catholyte, the middle section bath solution, the first isolating membrane and the second isolating membrane together form an electromigration system, wherein the middle section bath solution is an organic phase loaded with lithium obtained in the step (2), the first isolating membrane is arranged between the anolyte and the middle section bath solution, and the second isolating membrane is arranged between the middle section bath solution and the catholyte;
(4) Energizing the electrotransport system to obtain enrichment 7 Anode liquid and cathode liquid of Li.
In the above method, crown ether compound pair 6 Li has the enrichment function, under the action of an electric field, 7 li is enriched in the catholyte, and lithium ions are diffused from the intermediate tank solution to the anolyte due to the diffusion of the lithium ions, even under the condition of applying an electric field, and meanwhile, due to the crown ether compound pair 6 Li has enrichment effect, so that it diffuses in lithium ions in the anode liquid 7 The abundance of Li isotope is higher, and the Li isotope can also appear in anode liquid 7 And (3) enriching Li.
Compared with the prior art, the invention has the beneficial effects that:
(1) Under the action of an electric field, the lithium isotope separation effect continuously exists, the front end and the tail end of ion migration flow are not limited in lithium isotope enrichment, and the isolation film is not limited in saturated capacity; even if the proportion of lithium ions migrating into the aqueous phase accounts for more than 90% of the total amount of lithium in the system, the isotope separation effect is obvious.
(2) The multistage continuous separation process is simple to operate, continuous production can be realized, the separation efficiency is greatly improved, and the ionization decomposition of an organic phase is avoided by using a three-stage method;
(3) All solution phases can be recycled, and the process is clean and environment-friendly;
(4) The process has no special requirements on temperature, humidity, air and the like, and does not need sealing;
(5) The electrode liquid adopts aqueous phase solution, and the byproducts are only hydrogen and oxygen.
Detailed Description
In view of the shortcomings of the prior art, the inventor of the present application has long studied and put forward a great deal of practice, and the technical solution of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
One aspect of an embodiment of the invention provides a separation and enrichment 7 A method of Li isotope, comprising:
(1) Uniformly mixing the ionic liquid, the diluent and the crown ether compound to form an extraction organic phase;
(2) Uniformly mixing the extracted organic phase with a lithium salt solution, and collecting an organic phase loaded with lithium after extraction;
(3) The anode, the cathode, the anolyte, the catholyte, the middle section bath solution, the first isolating membrane and the second isolating membrane together form an electromigration system, wherein the middle section bath solution is an organic phase loaded with lithium obtained in the step (2), the first isolating membrane is arranged between the anolyte and the middle section bath solution, and the second isolating membrane is arranged between the middle section bath solution and the catholyte;
(4) Energizing the electrotransport system to obtain enrichment 7 Anode liquid and cathode liquid of Li.
In some more specific embodiments, the crown ether compounds include any one or a combination of two or more of aminobenzo 12-crown-4, aminobenzo 15-crown-5, aminobenzo 15-crown-4, aminobenzo 18-crown-6, monoazabenzo 12-crown-4, monoazabenzo 15-crown-5, monoazabenzo 15-crown-4, monoazabenzo 18-crown-6, formylbenzo 12-crown-4, formylbenzo 15-crown-5, formylbenzo 15-crown-4, and formylbenzo 18-crown-6.
In the invention, the crown ether compound is neutral molecule, and has no special requirement on extraction rate in the extraction process unlike the traditional extractant, and the crown ether compound has no special requirement on extraction rate in the extraction organic phase 6 Li has an enrichment effect.
Further, the ionic liquid comprises 1-butyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-octyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-hexyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-ethyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-propyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt; any one or a combination of two or more of N-butyl-N-methylpyrrolidine bis (trifluoromethylsulfonyl) imide salt, N-butyl-N-methylpiperidine bis (trifluoromethylsulfonyl) imide salt, tetrabutylphosphine bis (trifluoromethylsulfonyl) imide salt, tributylmethylamine bis (trifluoromethylsulfonyl) imide salt, 1-butyl-3-methylimidazole hexafluorophosphate, 1-vinyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-allyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-benzyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, and the like is not limited thereto.
Further, the diluent includes any one or a combination of two or more of anisole, methylene chloride, chlorobenzene, dichlorobenzene, toluene, xylene, carbon tetrachloride, dichloroethane, petroleum ether, ethyl acetate, n-butanol, toluene, n-heptane, butyl acetate, isopropyl ether, and isobutanol, and is not limited thereto.
In some more specific embodiments, the volume ratio of the ionic liquid to the diluent in step (1) is from 1:1 to 10.
Further, the concentration of crown ether compounds in the extracted organic phase is 0.1mol/L to 10mol/L.
In some more specific embodiments, the lithium salt solution includes a lithium salt and water.
Further, the lithium salt includes any one or a combination of two or more of lithium chloride, lithium bromide, lithium iodide, lithium acetate, lithium sulfate, lithium nitrate, lithium perchlorate, lithium trifluoroacetate, lithium trichloroacetate, lithium bis (trifluoromethanesulfonyl) imide, lithium cyanide, lithium thiocyanate, and lithium hydroxide, and is not limited thereto.
Further, the concentration of lithium ions in the lithium salt solution is 0.1mol/L to 20mol/L.
Further, the volume ratio of the extracted organic phase to the lithium salt solution is 1:0.1-20.
Further, the extraction method in the step (2) includes any one of stirring and shaking, and is not limited thereto.
Further, the extraction time is 0.5-2 h.
In some more specific embodiments, the anolyte in step (3) includes any one or a combination of two or more of an organic phase, a salt solution, and water, and is not limited thereto.
Further, the anolyte includes any one or a combination of two or more of ammonium salt solution, metal ion salt solution, and pure water, and is not limited thereto.
Further, the metal ions include any one or a combination of two or more of lithium ions, sodium ions, and potassium ions, and are not limited thereto.
Further, the concentration of ammonium ions and/or metal ions in the anolyte is below 0.1 mol/L.
In the invention, during the cyclic use, lithium ions can enter the anode liquid due to the diffusion effect, the concentration of the lithium ions in the anode liquid cannot be higher than that in the middle section swimming pool, and when the concentration of the lithium ions in the anode liquid is close to that in the middle section swimming pool, the anode liquid is replaced, and the original anode liquid is regenerated after extraction.
In some more specific embodiments, the catholyte in step (3) comprises any one or a combination of two or more of an organic phase, a salt solution, and water, and is not limited thereto.
Further, the catholyte includes any one or a combination of two or more of ammonium salt solution, metal ion salt solution, pure water, and is not limited thereto.
Further, the metal ions include any one or a combination of two or more of lithium ions, sodium ions, and potassium ions, and are not limited thereto.
Further, the concentration of ammonium ions and/or metal ions in the catholyte is below 0.1 mol/L. Further, the middle stage bath solution includes an organic phase loaded with lithium, and is not limited thereto.
In some more specific embodiments, the intermediate stage bath includes, but is not limited to, a lithium loaded organic phase.
Further, the preparation method of the lithium-loaded organic phase further comprises the following steps: obtained by direct dissolution of lithium salts in the extracted organic phase or by driving lithium ions into the extracted organic phase with an electric field.
Further, the concentration of lithium ions in the middle section groove liquid is more than 0.05 mol/L.
Further, when the concentration of lithium ions in the middle section tank liquor is lower than 0.05mol/L, a new middle section tank liquor can be replaced.
Furthermore, the middle section bath solution with the lithium ion concentration lower than 0.05mol/L can be reused through back extraction treatment.
In some specific embodiments, the materials of the first isolating film and the second isolating film comprise any one or more than two of polypropylene, polyethylene, polytetrafluoroethylene, polyethersulfone and polyvinylidene fluoride.
Further, the diameters of the pore passages of the first isolating membrane and the second isolating membrane are any one of micron-sized, submicron-sized and nanometer-sized, and are not limited to the above.
Further, the material of the anode includes any one or a combination of two or more of carbon, platinum, glassy carbon, palladium, tungsten and copper, and is not limited thereto.
Further, the material of the cathode includes any one or a combination of two or more of carbon, platinum, glassy carbon, palladium, tungsten and copper, and is not limited thereto.
In the method, the anolyte and the catholyte are respectively circulated externally at constant flow rates, the anolyte and the catholyte with different lithium isotope abundances are collected periodically, stored respectively and matched with organic phases with different lithium isotope abundances for use in different electric field application time periods.
In some more specific embodiments, the electric field employed by the electrotransport system comprises a direct current electric field applied for a period of time ranging from 0.5h to 120h.
Further, the application mode of the electric field includes any one of an uninterrupted electric field and an intermittent electric field, and is not limited thereto.
Further, the voltage used by the electric field is any one of a constant voltage and a voltage regulated periodically and regularly, and is not limited to the constant voltage and the voltage; the voltage used by the electric field can be constant, and the magnitude of the voltage can be regularly regulated according to a certain rule.
Further, the electric field has a strength of: the voltage over the distance per centimeter is 0.5V to 4V.
In some of the more specific embodiments of the present invention,
and (3) keeping the concentration of lithium ions in the middle section groove liquid in the step (3) above 0.05 mol/L.
Further, after the step (3), if the concentration of lithium ions in the middle section tank liquor is lower than 0.05mol/L, the middle section tank liquor is reused as the extraction organic phase in the step (2).
In some more specific embodiments, the method further comprises: enriching the product obtained in the step (4) 7 The catholyte of Li is applied again as catholyte to step (3), and steps (3) to (4) are repeated until enrichment is obtained 7 The concentration of lithium ions in the cathode liquid of Li reaches more than 2 mol/L.
Further, enriching the lithium ion concentration obtained in the step (4) to be more than 2mol/L 7 The catholyte of Li is applied again as a lithium salt solution to step (2) and steps (2) to (4) are repeated until enrichment is obtained 7 In the catholyte of Li 7 The Li abundance reaches a set value;
further, the enrichment 7 The concentration of lithium ions in the Li catholyte is 2mol/L to 10mol/L.
In the invention, different lithium isotope abundance, different voltages and different acquisition time periods in the middle section bath solution can influence the lithium isotope abundance acquired in the cathode solution. In the repeated use process of the cathode liquid, the lithium isotope abundance of the middle section bath liquid, the system application voltage and the acquisition time period are controlled in a certain range, so that the lithium isotope abundance in the recycled cathode liquid is ensured not to fluctuate too much. When the abundance, voltage or collection time period of the lithium isotopes in the middle-stage bath solution is obviously changed, the use of the cathode solution with corresponding lithium isotope abundance is also adjusted.
In some embodiments of the invention, the method may comprise:
preparing lithium salt aqueous solution, and preparing organic phase by using ligand with selective complexing effect on lithium isotope ion, lithium ion synergistic agent, conductive reinforcing agent and diluent;
extracting the lithium salt aqueous solution with the organic phase to obtain a lithium-loaded organic phase;
taking an organic phase loaded with lithium as a middle section bath solution, taking an aqueous phase solution containing low-concentration electrolyte as an anode solution and a cathode solution, and separating the anode solution, the middle section bath solution and the cathode solution by a diaphragm so as to construct and form an electromigration separation system;
and applying an electric field to the electromigration separation system to enable lithium ions in the middle section bath solution to migrate to the aqueous phase solution, wherein anode solution and cathode solution can be circulated outside the bath by a pump, and cathode solutions with different lithium isotope abundances are periodically collected and respectively stored so as to be matched with organic phases with different lithium isotope abundances to be used in different electric field application time periods.
When the concentration of lithium ions in the organic phase used as the middle-stage bath solution is low to a certain level, the organic phase is regarded as regeneration, and the organic phase can be reused for extracting lithium salt water solution to obtain the organic phase loaded with lithium and is continuously used for electromigration separation.
Wherein, when the concentration of lithium ions in the aqueous solution used as the catholyte reaches a set concentration, the regenerated organic can be used for extraction, and the raffinate can be used as the catholyte.
The extraction and electromigration processes described above may be alternately repeated until the lithium isotopes in the resulting catholyte reach a set abundance.
For example, in some more specific embodiments of the invention, catholyte may be collected and stored in a corresponding abundance tank every 4-8 hours; the stored catholyte can be reused until the concentration of lithium ions reaches 2mol/L to 10mol/L, and the organic phase loaded with lithium is reused as the middle section bath solution after the fresh or regenerated organic phase is extracted. A small amount of lithium remains in the depleted middle section groove liquid, and the middle section groove liquid is regenerated after back extraction and is recycled. The extraction and electromigration cycles of the process are repeated until the lithium isotope reaches the set abundance.
Due to the diffusion effect of lithium ions, the lithium ions still diffuse from the middle-section bath solution to the anode solution even under the condition of applying an electric field, and meanwhile, due to the crown ether compound pair 6 Li has enrichment effect, so that it diffuses in lithium ions in the anode liquid 7 The abundance of Li isotope is higher, and the Li isotope can also appear in anode liquid 7 And (3) enriching Li.
In the method, due to the diffusion effect of lithium ions, the lithium ions still diffuse from the middle section tank solution to the anode solution even under the condition of applying an electric field, and when the concentration of the lithium ions in the anode solution is higher than a set value, a new anode solution is replaced; original enrichment 7 Extracting anode liquid of Li and regenerating; when the lithium ion concentration of the middle section bath solution is lower than a set value, replacing a new organic phase loaded with lithium; the original lithium-depleted organic phase is regenerated by extracting lithium salt water solution and then is continuously used as the organic phase for loading lithium.
The technical scheme of the invention is further described in detail below with reference to a plurality of preferred embodiments, the embodiments are implemented on the premise of the technical scheme of the invention, and detailed implementation modes and specific operation processes are given, but the protection scope of the invention is not limited to the following embodiments.
The experimental materials used in the examples described below, unless otherwise specified, were all commercially available from conventional biochemicals.
Example 1
(1) Mixing 1-butyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt and anisole according to a volume ratio of 1:1, dissolving tetraacetyl-benzo 15-crown-5 to form an extraction organic phase, wherein the concentration of the tetraacetyl-benzo 15-crown-5 is 0.1mol/L, and preparing a lithium chloride solution with the concentration of lithium ions of 0.1 mol/L;
(2) Fully and uniformly mixing the extracted organic phase and the lithium chloride solution according to the volume ratio of 1:0.1, oscillating for 1h, and centrifugally collecting the organic phase loaded with lithium;
(3) The organic phase loaded with lithium is used as a middle section groove liquid, and 0.1mol/L ammonium chloride solutionAs anode liquid and cathode liquid, a polypropylene film as an isolating film, graphite as an anode, glass carbon as a cathode, an electric field voltage of 2V per cm distance, collecting the cathode liquid electrified for 0-8 h, 7 the abundance of Li is 92.56 percent, which corresponds to that in the anode liquid 7 The abundance of Li 92.60%;
(4) Taking the catholyte finally obtained in the step (3) as the catholyte again, and repeating the operation of the step (3) to collect the lithium ions which are migrated from the organic phase loaded with lithium until the concentration of the lithium ions in the catholyte reaches 2mol/L; then extracting the cathode solution with the lithium ion concentration reaching 2mol/L by using a lithium-free organic phase to obtain a lithium-loaded organic phase, and continuously repeating the extraction and electromigration processes; after 20 cycles, in the catholyte 7 The abundance of Li reaches 93.48%; corresponding to the anode liquid circulating for 1 time, the anode liquid is in 7 The abundance of Li 92.70%.
Example 2
(1) Mixing 1-vinyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt and dichloromethane according to a volume ratio of 1:10, dissolving bromo-benzo 15-crown-5 to form an extraction organic phase, wherein the concentration of the bromo-benzo 15-crown-5 is 10mol/L, and preparing a bis (trifluoromethanesulfonyl) imide lithium solution with the lithium ion concentration of 20 mol/L;
(2) Fully and uniformly mixing the extracted organic phase and a bis (trifluoromethanesulfonyl) imide lithium solution according to the volume ratio of 1:20, oscillating for 0.5h, and centrifugally collecting the organic phase loaded with lithium;
(3) Taking an organic phase loaded with lithium as a middle section bath solution, taking 0.01mol/L potassium chloride solution as an anode solution and a cathode solution, taking a polyethylene film as an isolating film, taking platinum as an anode, taking pure copper as a cathode, taking the electric field voltage of 0.5V per cm distance, collecting the cathode solution electrified for 0-120 h, 7 the abundance of Li is 92.61 percent, which corresponds to that in the anode liquid 7 The abundance of Li 92.68%;
(4) Taking the catholyte finally obtained in the step (3) as the catholyte again, and repeating the operation of the step (3) to collect the lithium ions which are migrated from the organic phase loaded with lithium until the concentration of the lithium ions in the catholyte reaches 10mol/L; then extracting the cathode solution with lithium ion concentration reaching 10mol/L by using a lithium-free organic phase to obtain a lithium-loaded organic phase, and continuingRepeating the extraction and electromigration processes; after 10 cycles, in the catholyte 7 The abundance of Li reaches 93.40%; corresponding to no circulation of the anolyte, the anolyte is 7 The abundance of Li 92.68%.
Example 3
(1) Mixing 1-butyl-3-methylimidazole hexafluorophosphate and dichloroethane at a volume ratio of 1:5, dissolving 4-nitro-benzo 18-crown-6 to form an extraction organic phase, wherein the concentration of 4-nitro-benzo 18-crown-6 is 5mol/L, and preparing a lithium nitrate solution with the lithium ion concentration of 10mol/L;
(2) Fully and uniformly mixing the extracted organic phase and the lithium nitrate solution according to the volume ratio of 1:10, oscillating for 2 hours, and centrifugally collecting the organic phase loaded with lithium;
(3) Taking an organic phase loaded with lithium as a middle section bath solution, taking 0.05mol/L sodium chloride solution as an anode solution and a cathode solution, taking a polyethylene film as an isolating film, taking palladium as an anode, taking pure tungsten as a cathode, taking the electric field voltage of 4V per cm distance, collecting the cathode solution electrified for 0-0.5 h, 7 the abundance of Li is 92.80 percent, which corresponds to that in the anode liquid 7 The abundance of Li is 92.88%;
(4) Taking the catholyte finally obtained in the step (3) as the catholyte again, and repeating the operation of the step (3) to collect the lithium ions which are migrated from the organic phase loaded with lithium until the concentration of the lithium ions in the catholyte reaches 6mol/L; then extracting the cathode solution with the lithium ion concentration reaching 6mol/L by using a lithium-free organic phase to obtain a lithium-loaded organic phase, and continuously repeating the extraction and electromigration processes; after 40 cycles, in the catholyte 7 The abundance of Li reaches 94.80%; circulating the corresponding anolyte for 2 times, and adding the anolyte 7 The abundance of Li is 93.70%.
In addition, the inventors have conducted experiments with other materials, process operations, and process conditions as described in this specification with reference to the foregoing examples, and have all obtained desirable results.
The various aspects, embodiments, features and examples of the invention are to be considered in all respects as illustrative and not intended to limit the invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.
The use of headings and chapters in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the present invention.
Throughout this disclosure, where a composition is described as having, comprising, or including a particular component, or where a process is described as having, comprising, or including a particular process step, it is contemplated that the composition of the teachings of the present invention also consist essentially of, or consist of, the recited component, and that the process of the teachings of the present invention also consist essentially of, or consist of, the recited process step.
It should be understood that the order of steps or order in which a particular action is performed is not critical, as long as the present teachings remain operable. Furthermore, two or more steps or actions may be performed simultaneously.
While the invention has been described with reference to an illustrative embodiment, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and substantial equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.
Claims (15)
1. Separation and enrichment 7 A method of Li isotopes, characterized by comprising:
(1) Uniformly mixing the ionic liquid, the diluent and the crown ether compound to form an extraction organic phase; wherein the crown ether compound is selected from any one or more than two of aminobenzo 12-crown-4, aminobenzo 15-crown-5, aminobenzo 15-crown-4, aminobenzo 18-crown-6, monoazabenzo 12-crown-4, monoazabenzo 15-crown-5, monoazabenzo 15-crown-4, monoazabenzo 18-crown-6, formylbenzo 12-crown-4, formylbenzo 15-crown-5, formylbenzo 15-crown-4 and formylbenzo 18-crown-6; the ionic liquid is selected from 1-butyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt, 1-octyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt, 1-hexyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt, 1-ethyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt and 1-propyl-3-methylimidazole bis (trifluoro sulfonyl) imide salt; any one or a combination of two or more of N-butyl-N-methylpyrrolidine bis (trifluoromethylsulfonyl) imide salt, N-butyl-N-methylpiperidine bis (trifluoromethylsulfonyl) imide salt, tetrabutylphosphine bis (trifluoromethylsulfonyl) imide salt, tributylmethylamine bis (trifluoromethylsulfonyl) imide salt, 1-butyl-3-methylimidazole hexafluorophosphate, 1-vinyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-allyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt, 1-benzyl-3-methylimidazole bis (trifluoromethylsulfonyl) imide salt; the diluent is selected from any one or more than two of anisole, dichloromethane, chlorobenzene, dichlorobenzene, toluene, xylene, carbon tetrachloride, dichloroethane, petroleum ether, ethyl acetate, n-butanol, toluene, n-heptane, butyl acetate, isopropyl ether and isobutanol;
(2) Uniformly mixing the extracted organic phase with a lithium salt solution, and collecting an organic phase loaded with lithium after extraction;
(3) The anode, the cathode, the anolyte, the catholyte, the middle section bath solution, the first isolating membrane and the second isolating membrane together form an electromigration system, wherein the middle section bath solution is an organic phase loaded with lithium obtained in the step (2), the first isolating membrane is arranged between the anolyte and the middle section bath solution, and the second isolating membrane is arranged between the middle section bath solution and the catholyte; the electric field strength adopted by the electromigration system is as follows: the voltage is 0.5V-4V at each centimeter distance;
(4) Energizing the electrotransport system to obtain enrichment 7 Li yangPolar liquid and catholyte;
(5) Enriching the product obtained in the step (4) 7 The catholyte of Li is applied to the step (3) again as the catholyte, and the steps (3) - (4) are repeated until the enrichment is achieved 7 The concentration of lithium ions in the cathode liquid of Li reaches more than 2mol/L;
(6) Enriching the lithium ion concentration obtained in the step (4) to be more than 2mol/L 7 The cathode solution of Li is applied to the step (2) again as a lithium salt solution, and the steps (2) to (4) are repeated until the obtained enrichment 7 In the catholyte of Li 7 The Li abundance reaches the set value.
2. The method according to claim 1, characterized in that: in the step (1), the volume ratio of the ionic liquid to the diluent is 1:1-10.
3. The method according to claim 1, characterized in that: in the step (1), the concentration of the crown ether compound in the extracted organic phase is 0.1mol/L to 10mol/L.
4. The method according to claim 1, characterized in that: the lithium salt solution comprises lithium salt and water; the lithium salt is selected from any one or more than two of lithium chloride, lithium bromide, lithium iodide, lithium acetate, lithium sulfate, lithium nitrate, lithium perchlorate, lithium trifluoroacetate, lithium trichloroacetate, lithium bis (trifluoromethanesulfonyl) imide, lithium cyanide, lithium thiocyanate and lithium hydroxide; the concentration of lithium ions in the lithium salt solution is 0.1 mol/L-20 mol/L.
5. The method according to claim 1, characterized in that: in the step (2), the volume ratio of the extracted organic phase to the lithium salt solution is 1:0.1-20.
6. The method according to claim 1, characterized in that: in the step (2), the extraction time is 0.5-2 h.
7. The method according to claim 1, characterized in that: in the step (3), the middle section bath solution comprises an organic phase loaded with lithium; the preparation method of the lithium-loaded organic phase further comprises the following steps: the lithium-loaded organic phase is obtained by dissolving the lithium salt directly in the extracted organic phase or by driving lithium ions into the extracted organic phase with an electric field.
8. The method according to claim 1, characterized in that: the first isolation film and the second isolation film are made of any one or more than two of polypropylene, polyethylene, polytetrafluoroethylene, polyether sulfone and polyvinylidene fluoride.
9. The method according to claim 1, characterized in that: the pore diameters of the first isolating membrane and the second isolating membrane are any one of micron-level, submicron-level and nanometer-level.
10. The method according to claim 1, characterized in that: the anode is made of any one or more than two materials selected from carbon, platinum, glass carbon, palladium, tungsten and copper.
11. The method according to claim 1, characterized in that: the cathode is made of any one or more than two materials selected from carbon, platinum, glass carbon, palladium, tungsten and copper.
12. The method according to claim 1, characterized in that: the electric field adopted by the electrotransport system is selected from a direct current electric field, and the application mode of the electric field is selected from an uninterrupted electric field and/or an intermittent electric field.
13. The method according to claim 1, characterized in that: and (3) keeping the concentration of lithium ions in the middle section groove liquid in the step (3) above 0.05 mol/L.
14. The method according to claim 1, characterized in that: and (3) after the step (3) is finished, if the concentration of lithium ions in the middle section tank liquor is lower than 0.05mol/L, the middle section tank liquor is reused as an extraction organic phase in the step (2).
15. The method according to claim 1, characterized in that: the enrichment 7 The concentration of lithium ions in the Li catholyte is 2mol/L to 10mol/L.
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| PCT/CN2020/106596 WO2021159674A1 (en) | 2020-02-14 | 2020-08-03 | Li isotope separation and enrichment method |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103801194A (en) * | 2012-11-05 | 2014-05-21 | 中国科学院上海有机化学研究所 | Extraction agent for separation of lithium isotopes and application thereof |
| CN105536537A (en) * | 2015-12-17 | 2016-05-04 | 中国科学院青海盐湖研究所 | Method for extracting lithium isotope |
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| JP5429658B2 (en) * | 2008-07-29 | 2014-02-26 | 独立行政法人日本原子力研究開発機構 | Lithium isotope separation and concentration method and apparatus, and 6Li isotope or 7Li isotope highly concentrated recovery system and recovery method |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103801194A (en) * | 2012-11-05 | 2014-05-21 | 中国科学院上海有机化学研究所 | Extraction agent for separation of lithium isotopes and application thereof |
| CN105536537A (en) * | 2015-12-17 | 2016-05-04 | 中国科学院青海盐湖研究所 | Method for extracting lithium isotope |
Non-Patent Citations (3)
| Title |
|---|
| High-efficiency technology for lithium isotope separation using an ionic-liquid impregnated organic membrane;Tsuyoshi Hoshino, Takayuki Terai,;Fusion Engineering and Design;vol 86(No 9-11);全文 * |
| Novel approaches for lithium extraction from salt-lake brines: A review;Gui Liu, Zhongwei Zhao, Ahmad Ghahreman;Hydrometallurgy;第vol 187卷;全文 * |
| 冠状化合物在锂同位素分离中的应用;束玉珍;吴继宗;邓惟勤;;核化学与放射化学(第01期);全文 * |
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