ANION-EXCHANGE METHOD FOR SEPARATION OF YTTERBIUM FROM HOLMIUM AND ERBIUM

The separation of Yb(III) from Ho(III) complexes with HEDTA as well as separation of Yb(III) from Er(III) in the macro-micro system on the a nion exchangers Dowex 1 x 2 and Dowex 1 x 4 in the HEDTA form was stud ied by frontal analysis. This research was based on the determined aff inity series of rare earth element complexes with HEDTA at pH 4.0 and pH 7.5 for the anion exchanger Dowex 1 x 2 as well as on the calculate d values of the distribution coefficients of the Yb(III) and Ho(III) c omplexes with HEDTA at pH 4.0 and 7.5 on the anion-exchangers Dowex 1 x 2, Dowex 1 x 4 and Dowex 1 x 8. The presented method is an effective means of ytterbium purification from the heavy lanthanides holmium an d erbium. (C) 1997 Elsevier Science B.V.