The Separation of the Cerium-group Rare Earth Elements by Ion Exchange using a Citrate-acetate Mixed Solution as Eluting Agent

The separation of rare earth elements by ion exchange was studied. The new eluting agent consists of an aqueous solution of diammonium hydrogencitrate and an aqueous ammoniaacetic acid mixture; the two solutions were mixed in definite ratios. Using a column of Dowex 50 W resin, the separation of Sm, Nd, Pr, Ge and La was successfully achieved. As practical samples, mixed chlorides obtained from monazite concentrates were used. Both the purities and the yields of the recovered rare earths were greater than 99%. This eluting agent was applied to the separation of yttrium-group rare earths such as Dy, Er, Yb and Y, but the attempt was not successful.