Separation and enrichment method for lithium isotopes

Abstract

The invention discloses a separation and enrichment method for lithium isotopes. The method comprises the steps that S1, an extracted organic phase is prepared, wherein a crown ether derivative represented as the formula A or the formula B is taken as an extraction agent, and the extraction agent, hydrophobic ionic liquid and a diluent are mixed to obtain the extracted organic phase; S2, an extracted water phase is prepared, wherein water-soluble lithium salt is prepared into a lithium salt solution, and the lithium salt solution is taken as the extracted water phase; S3, after the extracted organic phase and the extracted water phase are fully mixed and extracted, phase splitting is conducted, and a load organic phase and extraction raffinate are obtained; S4, the load organic phase is burned for 30-200 min at the temperature of 400-1,000 DEG C, and a slag phase is obtained; S5, the slag phase is dissolved with water, solid-liquid separation is conducted, and 6Li enrichment liquid isobtained; S6, the 6Li enrichment liquid is taken as the extracted water phase, and the steps of S3-S5 are repeated. The invention provides a brand new technology method without adopting the reverse extraction operation based on a crown ether extraction system. The technology method is a quick cross flow superposing multi-level cascade separation method capable of enriching the methods of conducting separation and enrichment treatment on lithium isotopes.

Description

technical field [0001] The invention belongs to the technical field of separation and enrichment of lithium isotopes, and specifically relates to a method for separation and enrichment of lithium isotopes. Background technique [0002] my country puts the development of nuclear power in a very important position. At the same time, China is also a major participant in the International Controlled Thermonuclear Fusion (ITER) project, and the country has launched related projects for this purpose. For example, in 2002, the Southwest Institute of Physics of the Ministry of Nuclear Industry built the "National Circulator No. 2A", which carried out pre-research on key engineering technologies such as new divertors and superconducting magnets, engineering test reactor design, material research and key components The pre-research provides a technical and physical basis for the design and construction of a deuterium-tritium combustion test device. In 2006, the Institute of Plasma Ph...

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Problems solved by technology

However, on the one hand, these methods for the separation and enrichment of lithium isotopes are still at the exploration level of a single-stage system, and the efficiency of separation and enrichment is limited; on the other hand, the general process of the solvent liquid-liquid extraction method based on crown ether is also The process of extraction-stripping, however, current studies have shown that lithium isotopes in the enriched phase can be stripped with high-concentration hydrochloric acid solutions, and the lithium isotopes in the loaded organic phase can be extracted at least five times in a row. 6 Li is relatively completely recovered, and the back extraction method has great advantages in single-stage extraction and separation, and can be regenerated to achieve the purpose of recycling the organic phase and reducing the cost of separation.

However, when applied to multi-stage extraction and separation, since the pH value has a great influence on lithium isotope extraction and separation (such as J.Xiao et al.Journal of Molecular Liquids.2016,223:1032-1038), it cannot be used under acidic conditions. extraction and separation

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