Sur la séparation des terres rares XI. Systèmes de solubilité binaires et ternaires comprenant des nitrates des terres cériques

Abstract

AbstractThe solubility polytherms of the binary systems R(NO3)3‐H2O (R = La, Ce, Pr, Nd and Sm) have been established between 0° and 50°. The nitrate hexahydrates of lanthanum and cerium are not isotypic with the corresponding salts of the other membres of the rare earth group. This fact is responsible for the solubility anomaly already discovered by QUILL and ROBEY(Ce(NO3)3,6H2O is the most soluble salt of series) and for the miscibility gap occurring in the solid phases of the systems comprising the two types of the rare earth nitrate hexahydrates. Five ternary systems have been investigated at various temperatures, using a new technique which yields homogeneous mixed cristals.