COMPARATIVE-STUDY OF THE MUTUAL SEPARATION CHARACTERISTICS FOR NEIGHBORING RARE-EARTH ELEMENTS FROM QUATERNARY SYSTEMS LACL3-CECL3-PRCL3-NDCL3 AND LA2O3-CEO2-PR6O11-ND2O3 VIA VAPOR COMPLEXES LNAL(N)CL(3N+3)

A comparative study has been carried out for the mutual separation cha racteristics of neighboring rare earth elements La, Ce, Pr and Nd from the quaternary mixtures LaCl3CeCl3-PrCl3-NdCl3 and La2O3-CeO2-Pr6O11- Nd2O3 using a chemical vapor transport reaction mediated by the vapor complexes LnAl(n)Cl(3n+3) under a suitable temperature and pressure gr adient within 6 h. More efficient separation was observed from the oxi de mixture than from the chloride mixture. The separation factor, expr essed as atomic ratio for the resulting chlorides, for Pr.Nd was 1.98 from the quaternary chloride mixture and 7.25 from the quaternary oxid e mixture, respectively. (C) 1998 Elsevier Science S.A.