SEPARATION OP RARE EARTH - POLYALZDTOCARBOXYLIC ACIDS COMPLEXES OK VARIOUS TYPES OF ANION-EXCHANGERS

Abstract

ABSTRACT There has been shown the application of frontal analysis in purification of rare earth elements in complexes with EDTA on anion exchanger in the EDTA form and with IMDA on anion exchanger as an iminodi-acetate form in macro - microcomponent systems. The presented method with EDTA is effective in purification of yttrium from neodymium and terbium, lanthanum from neodymium, erbium from dysprosium and gadolinium from europium but with IMDA in purification of yttrium from heavy lanthanides (especially from ytterbium) and neodymium from yttrium. Out of the examined standard anion-exchangers Dowex in the system with EDTA Dowex 2 of functional benzyldimethylhydroxyethylammonium groups proved to be the moat effective in purification of yttrium from neodymium. The obtained results confirm the hypothesis that the complex structure is decisive in separation of ra-re-earth - EDTA complexes on anion-exchangers in the EDTA form but in the case of rare-earth-IMDA complexes the difference in their stability cons...