Method for separating and recovering rare earth elements

Abstract

The purpose of the present invention is to provide a method whereby rare earth elements can be separated and recovered at a higher yield than by conventional techniques. The method for separating and recovering rare earth elements, whereby multiple kinds of rare earth elements are separated and recovered, comprises: a step for achieving chemical equilibrium among rare earth halides of rare earth elements of group 1 and rare earth oxyhalides of rare earth elements of group 2, by chemically reacting a mixture, said mixture containing halides of the multiple kinds of rare earth elements, in the presence of an oxygen source, or by chemically reacting a mixture, said mixture containing oxides of the multiple kinds of rare earth elements, in the presence of a halogen source; a step for pouring the rare earth halides and the rare earth oxyhalides into water to selectively dissolve the rare earth halides in water, and thus extracting the rare earth halides into a liquid phase while allowing the rare earth oxyhalides to remain as a solid phase; and a step for subjecting the liquid phase, which contains the rare earth halides extracted therein, and the solid phase of the remaining rare earth oxyhalides to solid / liquid separation to thereby separate the rare earth elements of group 1 from the rare earth elements of group 2.

Description

technical field [0001] The invention relates to a technology for separating and recovering rare earth elements, in particular to a method for separating and recovering rare earth elements from a composition containing multiple rare earth elements. Background technique [0002] In recent years, we have recognized the importance of continuous protection of the global environment and concentrated our efforts on the development of industrial systems and transportation systems that use the least amount of fossil fuels. Examples of such environment-friendly systems and products include wind power generation systems, railway systems, hybrid vehicles, electric vehicles, and energy-saving air compressors. [0003] One of the main devices of these environment-friendly systems and products is a high-efficiency rotating electric machine (motor or generator) in which magnets containing rare earth elements (so-called rare earth magnets) are widely used. For example, rare earth magnets us...

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Problems solved by technology

[0004] On the other hand, rare earth elements are expensive because they are difficult to separate and refine as individual elements. Therefore, the development of technologies or alternative materials to reduce the amount of use while maintaining the performance of magnets is carefully considered.

However, it will take time for these technologies to be practical

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