Method for efficiently recovering valuable elements from rare earth molten salt electrolytic slag

Abstract

The invention discloses a method for efficiently recovering valuable elements from rare earth molten salt electrolytic slag. According to the method for efficiently recovering the valuable elements from the rare earth molten salt electrolytic slag, the rare earth molten salt electrolytic slag is uniformly mixed with a lithium source to obtain a mixture; and the mixture is sequentially subjected toone-stage vacuum roasting and two-stage vacuum distillation to obtain high-purity lithium fluoride. The method for efficiently recovering the valuable elements from the rare earth molten salt electrolytic slag is based on the characteristics that a melting boiling point of the lithium fluoride is lower than that of rare earth fluoride and the vapor pressure of the lithium fluoride is higher thanthat of the rare earth fluoride, the less volatile rare earth fluoride in the slag is converted into volatile lithium fluoride through the one-stage vacuum roasting firstly, then fluorine resources are recovered in the form of the lithium fluoride through the two-stage vacuum distillation process, so that vacuum distillation temperature, distillation time and distillation energy consumption can beeffectively reduced, clean separation of fluorine and rare earth in the slag is realized, a comprehensive recovery rate of the fluorine and the rare earth is further improved, green high-value comprehensive recycling of the rare earth, the lithium and the fluorine resources in the rare earth molten salt electrolytic slag is realized, and the comprehensive recovery rate of the rare earth and fluorine elements can reach more than 99% at the highest.

Description

technical field [0001] The invention belongs to the field of recycling and reuse of rare earth molten salt electrolytic slag resources, and in particular relates to a method for efficiently recovering valuable elements from rare earth molten salt electrolytic slag. Background technique [0002] Rare earth metals are widely used in metallurgy, petrochemical, machinery, electronics, new energy, military industry, agriculture and other fields, especially with the rapid development of rare earth hydrogen storage alloy and NdFeB permanent magnet material industry, the demand for rare earth metals and alloys The amount is getting bigger and bigger. At present, the preparation of rare earth metals such as lanthanum, cerium, praseodymium, neodymium, praseodymium neodymium, and dysprosium iron and their alloys are all prepared by fluoride system molten salt electrolysis process. However, during the production process, a large amount of rare earth molten salt electrolytic slag will b...

AI Technical Summary

Problems solved by technology

However, due to the high melting and boiling point and non-volatile characteristics of rare earth fluoride, higher distillation temperature and harsher vacuum distillation conditions are required, and there are problems of high vacuum distillation energy consumption and incomplete defluorination.

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