Method for separating and enriching < 7 > Li isotope through extraction-electromigration coupling

Abstract

The invention discloses a method for separating and enriching < 7 > Li isotope through extraction-electromigration coupling. The method comprises the following steps: uniformly mixing an ionic liquid, a diluent and a crown ether compound to form an extraction organic phase; uniformly mixing the extracted organic phase with a lithium salt solution, extracting, and collecting a lithium-loaded organic phase; the anode, the cathode, the anolyte, the catholyte and the isolating membrane jointly form an electromigration system, wherein the anolyte is the obtained lithium-loaded organic phase, and the isolating membrane is arranged between the anolyte and the catholyte; and finally, electrifying the electromigration system to obtain the cathode solution rich in < 7 > Li. According to the method, under the action of an electric field, the lithium isotope separation effect continuously exists, the enrichment limitation of the front end and the tail end of an ion migration flow does not exist, the isolation membrane is not subjected to saturation capacity limitation, meanwhile, all solution phases can be recycled, and the process is clean and environment-friendly; in addition, the process has no special requirements on temperature, humidity, air and the like, and sealing is not needed.

Description

technical field [0001] The invention belongs to the technical field of lithium isotope separation and enrichment, and specifically relates to an extraction-electromigration coupled separation and enrichment 7 Li isotope method. Background technique [0002] High-abundance lithium isotopes play an important role in national economy and national defense security. More than 99.9% abundance 7 LiOH is an acidity regulator for pressurized water reactors, 7 LiBeF is the neutron moderator of the new molten salt reactor. 30%~90% abundance 6 Li is an indispensable raw material for fusion reactors and hydrogen bombs, and is also used in various neutron detectors. With the maturity of molten salt reactor and fusion reactor technology, domestic and foreign markets will demand 7 Li and 6 Li's demand will increase day by day. and 7 Li and 6 The natural abundances of Li are 92.5% and 7.5%, respectively, which cannot be directly applied to the above fields, and must be separated by...

AI Technical Summary

Problems solved by technology

In the organic solution, the difference in the distribution ratio of lithium isotopes in the solvent, cathode, and anode materials is used to achieve separation. In this method, the upper-level enrichment products are mostly metallic lithium or lithium solid compounds, which cannot be directly used as raw materials for the next-level. Multi-stage continuous separation; the organic solvents used are mostly carbonate electrolytes, which are sensitive to air and water and require airtight operation

In addition, most of the existing electrochemical separation technologies require batch injection, and only have obvious isotope separation effects at the front and end of the lithium ion migration flow, and most of the lithium ion migration flow in the middle has no separation effect. resulting in inefficient use of current