SEPARATION METHOD OF RARE EARTH ELEMENTS FROM THE LEACHING SOLUTION OF WASTE PHOSPHORS

摘要

The present invention relates to a method for efficiently separating and recovering various kinds of rare earth elements dissolved in a waste phosphor leachate. The method according to the invention is a method for separating said elements from a leachate comprising yttrium (Y), europium (Eu), terbium (Tb), lanthanum (La) and cerium (Ce), comprising: (a) di-2 selectively separating yttrium (Y) contained in the leachate using a single extractant containing ,4,4-trimethylpentyl phosphinic acid; (b) Europium (Eu) and terbium from the extraction filtrate from which the yttrium (Y) was separated using a mixed extractant containing di-2,4,4-trimethylpentyl phosphinic acid and tri-octyl/decyl amine selectively isolating (Tb); (c) separating europium (Eu) and terbium (Tb) extracted from the mixed extractant through scrubbing using a terbium (Tb) solution; and (d) lanthanum (La) and cerium (Ce) contained in the extraction filtrate from which europium (Eu) and terbium (Tb) were selectively separated in step (b) by precipitating cerium (Ce) in an oxidizing atmosphere. Separation step; includes.