METHOD FOR COLLECTING RARE-EARTH METAL, MOLTEN SALT ELECTROLYSIS APPARATUS, AND BIPOLAR ELECTRODE-TYPE DIAPHRAGM

摘要

PROBLEM TO BE SOLVED: To provide a method for collecting rare-earth metal which enables collection of the rare-earth metal to be operated for a long term with stability by overcoming drawbacks in conventional methods for collecting rare-earth metal.SOLUTION: A method for collecting rare-earth metal is provided which involves the use of a bipolar electrode-type diaphragm 5 that includes a rare-earth metal alloy in order to provide a separation between an anode 6 and a cathode 7 to form an anode compartment 3 and a cathode compartment 4. The anode compartment 3 side is supplied with rare-earth metal ions, while voltage is applied between the anode 6 and the cathode 7 to allow molten salt electrolysis to take place, and thereby the rare-earth metal is diffusion-transmitted in the bipolar electrode-type diaphragm 5, resulting in the deposition of the rare-earth metal or an alloy thereof on a surface of the cathode 7. The bipolar electrode-type diaphragm 5 is obtained by allowing a rare-earth metal alloy 5a to be retained by a material 5b inert to the molten salt.SELECTED DRAWING: Figure 1