SEPARATION OF PAIR LA(III)-ND(III) ON CHELATING ION-EXCHANGER OF AMINO-ACID AND PHOSPHONIC TYPES

The purification process of 95% lanthanum(III) concentrate from neodym ium(III) was studied on various types of chelating ion-exchangers by m eans of elution with mineral acids. Chelating ion-exchangers of the im inodiacetate and amino-phosphonic functional groups as well as of a ph osphonic functional group were examined with respect to their usefulne ss in this process. The iminodiacetate ion-exchanger Duolit ES 466 pro ved to be the best of the applied ion-exchangers. As a result of the p urification process on this ion-exchanger lanthanum(III) of neodymium( III) content < 0.05% was obtained.