A novel separation technology for a heavy rare earth residue using a solvent impregnated resin

Heavy rare earths, which are contained in small amount in ores such as bastnaesite and monazite, have been accumulated as a heavy rare earth residue without separation and purification due to the lack of suitable methods. The heavy rare earth residue includes the seven rare earth elements Tb, Dy, Ho, Y, Er, Tm and Yb. A separation and recovery process for Dy, Y, Tm and To from a liquor produced by leaching the heavy rare earth residue was investigated by using a column method with a solvent impregnated resin. The solvent impregnated resin was prepared by impregnation with the organophosphorous extractant whose trade name is PC-88A of a macro porous resin, Amberlite XAD-7. It was almost impossible to separate the rare earths in simple adsorption and elution steps. However, the individual separation of Dy, Y, Tm and Yb from the leach liquor was achieved by first changing the eluent concentration gradually from pH2 to 2mol/dm(3) HCl in the elution step, and secondly by using a development column and changing the eluent concentration in the elution step. A separation process now sheet was proposed for the heavy rare earth residue by using the solvent impregnated resin method.