Studies on separation of iminodiacetate complexes of lanthanum (III) from neodymium (III) and praseodymium (III) on anion-exchangers

Abstract

Based on the determined breakthrough curves the affinity series Ln (III):iminodiacetic acid (IMDA)=1:2, pH 5.07–6.0 for most rare earth element complexes was found for the anion-exchanger Dowex 1×4 in the acetate 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 (III) and Pr (III) in the determined affinity series of rare earth complexes with IMDA the separation of La(III) from Nd(III) as well as separation 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 Dowex 2×8 (type 2) in the acetate and IMDA forms was studied by frontal analysis. The best results were obtained using Dowex 1×4 and Dowex 2×8. The method presented is an effective means of lanthanum purification from the neighbouring lanthanides, praseodymium and neodymium.