PROCESS FOR REMOVING LEAD FROM RARE EARTHS

摘要

Process for removing lead from rare earths in the form of chlorides in aqueous solution, consisting in: - performing a liquid-liquid extraction between an aqueous phase containing at least one rare earth and the lead in the form of chlorides, and an organic phase containing an extraction agent consisting of an alkyl monoester of an alkylphosphonic acid: the aqueous phase brought into contact with the organic phase having at the time of the extraction a chloride ion concentration of at least 2 moles/litre and a pH higher than or equal to 2 and lower than or equal to 4, - then recovering the rare earth(s) from the organic phase.