Reindarstellung von Terbiumoxid durch Craig-Verteilung

摘要

In the preparative Craig distribution of Tb-nitrate between HNO3and tributyl phosphate the method of lower phase withdrawal using 12m-HNO3has been shown to be far superior to upper phase withdrawal; the superiority becomes even more marked as the atomic number of the rare earth element increases. From mixtures enriched in Tb by oxidation melting, Tb4O7of more than 99 purity was separated, from which Tb4O7of over 99.9 purity was obtained in 87 yield using up to 960 effective stages.