Method for recovering rare earth elements in rare earth molten salt electrolytic slag through sub-molten salt method

Abstract

The invention belongs to the technical field of rare earth secondary resource recovery and recycling, and provides a method for recovering rare earth elements in rare earth molten salt electrolytic slag through a sub-molten salt method, which comprises the following steps: S1, treating the rare earth molten salt electrolytic slag through the sub-molten salt method to obtain an alkaline solution and reaction slag; s2, the reaction residues are subjected to acid leaching, and a leaching solution is obtained; s3, performing impurity removal and precipitation on the leachate to obtain rare earth salt precipitation; and S4, roasting the rare earth salt precipitate to obtain the rare earth oxide. Aiming at the technical problems existing in the chemical recovery process of the rare earth elements in the rare earth molten salt electrolytic slag, the rare earth elements in the rare earth molten salt electrolytic slag are recovered by the sub-molten salt method by utilizing the high chemical reactivity of the sub-molten salt medium, and the method has the advantages of high operability, simple process, low cost, low reaction temperature, no secondary pollution and the like; and efficient recycling of rare earth elements in the rare earth molten salt electrolytic slag is achieved.

Description

technical field [0001] The invention belongs to the technical field of rare earth secondary resource recovery and recycling, and in particular relates to a method for recovering rare earth elements in rare earth molten salt electrolytic slag by a sub-molten salt method. Background technique [0002] Rare earth elements are important strategic resources. One out of every six inventions and discoveries of new technologies and new materials in today's world is inseparable from rare earth elements, which has also resulted in an increasing demand for rare earth elements. How to maintain a long-term stable supply of rare earth resources and meet the growing demand for rare earth elements in the development of high-tech industries is a problem that the rare earth industry must face. The rational development and utilization of rare earth elements in rare earth waste is an effective way to save rare earth resources and realize the green and sustainable development of rare earth indus...

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Problems solved by technology

[0006] Aiming at the deficiencies of the existing technology, a method for recovering rare earth elements in rare earth molten salt electrolytic slag by the sub-molten salt method is provided. Steel needles are selected as the base material, and the complex composition of rare earth molten salt electrolytic slag, alkali fusion, roasting and other traditional recovery processes are provided. Low synergistic recovery rate of valuable elements, long process, large energy consumption, easy to cause secondary pollution and other problems, the present invention utilizes the high chemical reactivity and high activity active oxygen ions provided by sub-molten salt unconventional medium to realize rare earth molten salt electrolysis Phase transformation of slag and recovery of rare earth elements in it to reduce energy consumption, increase the recovery rate of rare earth elements, and realize green, low-carbon and efficient leaching of rare earth elements in rare earth molten salt electrolytic slag

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