METHOD FOR RECOVERING HEAVY RARE EARTH ELEMENT

摘要

The purpose of the present invention is to provide a method for recovering a heavy rare earth element, which enables the recovery of a heavy rare earth element with high efficiency and at a high recovery rate. In the present invention, an alkali metal sulfuric acid salt is added to a solution containing a heavy rare earth element and a light rare earth element in such a manner that the concentration of the alkali metal sulfuric acid salt in the resultant solution becomes 27 g/l or more in terms of a sulfate ion concentration, to cause the heavy rare earth element and the light rare earth element to co-precipitate as a double sulfate, thereby recovering the heavy rare earth element. It is preferred that the temperature of the solution is set at a temperature falling within the range from 55 to 100°C inclusive, and it is also preferred that the solution is agitated for 20 minutes or longer after the addition of the alkali metal sulfuric acid salt. It is also preferred that the solution is prepared in such a manner that the molar ratio of the light rare earth element to the heavy rare earth element in the solution becomes 3 or more.