Preparation of High Purity Rare Earth Metals of Samarium, Ytterbium and Thulium

Abstract

Abstract High purity rare earth metals, including samarium, ytterbium and thulium, were prepared by vacuum reduction-distillation of each rare earth oxide with lanthanum metal. The results show that the rare earth metals of samarium and ytterbium with 4N-purity are obtained by direct vacuum reduction-distillation, and their purity is 99.99 wt% and 99.993 wt%, respectively, with respect to 75 impurities. There is a high concentration of reductant in thulium metal due to the higher reaction temperature and lower distillation velocity ratio of metallic thulium to lanthanum, so that the sublimation purification with lower temperature and high vacuum is needed. The purified thulium can reach a high purity of 99.995wt% with respect to 75 impurities. Therefore, the preparation of high purity reductant of lanthanum metal, especially of total amount control of metallic impurities, is the key step to obtain 99.99%-purity rare earth metallic samarium, ytterbium and thulium