Separation of Rare Earth Elements in Monazite Sand by Anion Exchange Resin (II)

An anion exchange method for separating the individual rare earth elements in monazite into enriched fractions has been developed. The complexed rare earth ions with EDTA at pH 8.4 pass through the anion resin bed. The absorption order of the complexed ions was in accord with that of the stability constants of the complexes. The elution of a mixture of all the rare earths through an ion-exchange bed with an ammonia-buffered solution of EDTA indicated that this chelating agent is as effective for separating the light rare earths. The separation results of each ion obtained from their elution fractions are 55% to 98%.