STUDIES ON SEPARATION OF IMINODIACETATE COMPLEXES OF LANTHANUM (III) FROM NEODYMIUM (III) AND PRASEODYMIUM (III) ON ANION-EXCHANGERS

Based on the determined breakthrough curves the affinity series Ln (II I):iminodiacetic acid (IMDA) = 1:2, pH 5.07-6.0 for most rare earth de ment complexes was found for the anion-exchanger Dowex 1 X 4 in the ac etate and IMDA forms to be as follows: Dy (III) > Ho (III) > Gd (III) > Eu (III) > Er (III) > Y (III) > Sm (III) > Tm (III) > Nd (III) > Pr (III) >> La (III). Taking into account the position of La (III), Nd (I II) and Pr (III) in the determined affinity series of rare earth compl exes with IMDA the separation of La(III) from Nd(III) as well as separ ation of La (III) from Pr (III) in the macro-micro system on the anion -exchangers Dowex 1 (type 1) of cross-linking 2, 4 and 8% DVB and Dowe x 2 X 8 (type 2) in the acetate and IMDA forms was studied by frontal analysis. The best results were obtained using Dowex 1 x 4 and Dowex 2 x 8. The method presented is an effective means of lanthanum purifica tion from the neighbouring lanthanides, praseodymium and neodymium. (C ) 1998 Elsevier Science B.V. All rights reserved.