| 摘要 |
Provided is a method for separating rare earth elements, the method comprising: a first heat treatment step for generating a plurality of rare earth halides from a starting material mixture that contains a plurality of rare earth oxides and an ammonium halide, and heating in a non-oxidizing atmosphere at a temperature that is not lower than the temperature at which the rare earth halides are generated from the rare earth oxides but lower than vaporization temperature of the rare earth halides; a second heat treatment step for generating a halide/oxyhalide mixture that contains rare earth halides of a first group of rare earth elements and rare earth oxyhalides of a second group of rare earth elements from the plurality of rare earth halides, and heating in an oxidizing atmosphere that contains H2O; a selective extraction step of introducing the halide/oxyhalide mixture into a solvent and selectively dissolving the rare earth halides into the solvent so as to extract the rare earth halides into a liquid phase and allow the rare earth oxyhalides to remain as a solid phase; [・・・V1] and a separation step of subjecting the liquid phase, into which the rare earth halides have been extracted, and the solid phase of the rare earth oxyhalides to solid-liquid separation so as to separate into a first group of rare earth elements and a second group of rare earth elements. |
