A method for separating and enriching lithium isotopes

Abstract

The invention discloses a method for separating and enriching lithium isotopes, which comprises the steps of: S1, preparing an organic phase for extraction: using a crown ether derivative represented by the following formula A or formula B as an extracting agent, mixing the extracting agent with hydrophobic ions The liquid and the diluent are mixed to obtain an extraction organic phase; S2, the extraction water phase is prepared: the water-soluble lithium salt is prepared into a lithium salt solution, which is used as the extraction water phase; S3, the extraction organic phase and the extraction water phase are fully mixed and extracted and then separated. phase, to obtain a loaded organic phase and a raffinate; S4, calcining the loaded organic phase at a temperature of 400°C to 1000°C for 30min-200min to obtain a slag phase; S5, to dissolve the slag phase with water, and perform solid-liquid separation to obtain 6 Li enrichment solution; S6, with 6 The Li enriched solution is used as the extraction water phase, and the above steps S3 to S5 are repeated. Based on the crown ether extraction system, the invention provides a brand-new process method without back-extraction operation, is a rapid superposition cross-flow multi-stage cascade separation method, and enriches the method for separating and enriching 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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