METHOD OF EXTRACTING RARE-EARTH ELEMENTS FROM A SOLID MIXTURE CONTAINING HALOPOSPHATE AND CONNECTING ONE OR MULTIPLE RARE-EARTH ELEMENTS

摘要

The method according to the invention for extracting rare earth elements from a solid mixture containing halophosphate and at least one compound of one or more rare earth elements, comprises: (a) acid etching the mixture; (b) adding a base to raise the pH to at least 1.5; (c) exposing the solid phase obtained in step (b) to a solution of sodium hydroxide or potassium hydroxide; (d) acid etching the solid phase from step (c) until a pH is below 7, whereby a solid phase and a liquid phase containing at least one rare earth salt are obtained, and the solid phase is separated from the liquid phase.