METHOD FOR SEPARATING AND RECOVERING RARE EARTH ELEMENT

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PROBLEM TO BE SOLVED : To provide a method that enables separation and recovery of several kinds of rare earth elements easily and in good yield. SOLUTION : The method includes steps of : adding metal M in a predetermined amount to a mixture including a halide of the plural kinds of rare earth elements; heating the added mixture under atmospheric pressure to cause the mixture to reach a chemical equilibrium state that a divalent halide of the plural kinds of rare earth elements and a halide of the metal M generate; evacuating a system in the chemical equilibrium state to generate metal and a trivalent halide of one of the rare earth elements from a divalent halide of one of the plural kinds of rare earth elements with disproportionation reaction; and performing vacuum distillation in the system to separate the mixture into a distillation aggregate and a residue of the trivalent halide of one of the rare earth elements. The metal M is metal which can coexist in three phases of the metal M, oxide of the metal M, and the halide of the metal M, under chemical equilibrium state environment. The predetermined amount is excessive amount than a chemical equivalent to the halide of the plural kinds of rare earth elements. COPYRIGHT : (C)2013, JPO&INPIT