Separation of Dy,Y,Tm and Yb from heavier rare earth residue with solvent impregnated resin

摘要

Heavier rare earth, which is contained in a small amount in ores such as bastnesite and monazite, has been accumulated as a heavier rare earth residue without doing separation and purification due to the lack of suitable methods. The heavier rareearth residue includes seven rare earth elements such as Tb, Dy, Ho, Y, Er, Tm and Yb. Separation and recovery process of Dy, Y, Tm and Yb from leached solution of the heavier rare earth residue was investigated by using a column method with solventimpregnated resin. The solvent impregnated resin was prepared by impregnation of organophosphorous extractant whose trade name is PC-88A into a macro porous resin, Amberlite XAD-7. It was almost impossible to separate them in simp1e adosorption andelution steps. However, we attained to individually separate Dy, Y, Tm and Yb from the leached solution first by changing eluent concentration gradually from pH2 to 0.02kmol/m{sup}3 HCl in the elution step, and secondly by using a development column andchanging eluent concentration in the elution step. The separation process flow was proposed for a heavier rare earth residue by using the solvent impregnated resin method.