A fundamental study on the production of rare earth metals (Sm, Eu, Tm and Yb) by direct reduction process

Kazuyoshi SHIMAKAGE, Kazuhiko ENDO, Tadao SATO, Hiroshi KATAYAMA
1989 Shigen-to-Sozai  
In the current investigation, reduction behaviours of samarium, europium thulium and ytterbium oxides with each rare earth metal (La, Ce, Nd and Pr) have been examined under the conditions of high temperature and vacuum atmosphere. Compact samples were prepared by pressing mixtures of both oxide and reducing agent. The experimental results obtained are summarized as follows: (1) Reduction reaction of each oxide with mischmetal rapidly proceeded with time at early stage and showed slow progress
more » ... t the middle and final stages. The reactivity for the reduction of each oxide was better in the order of europium oxide>ytterbium oxide>samarium oxide>thulium oxide. This result is in fair agreement with the thermodynamic evaluation. (2) The reactivity of each oxide differed with the kind of rare earth metals used as the reducing agents. (3) In the case of the reduction at low temperature region, the melting point of the reducing agent was considered to be one of important factors for accelerating the reduction reaction of rare earth oxides. (4) In order to recover each rare earth metal having high purity, the reduction of oxides must be carried out at low temperature region because the vapour pressure of the reducing reagent affects the reduction reaction at high temperature region. (5) For the reduction at low temperature region, metallic. cerium and lanthanum were more effective than metallic neodymium and praseodymium as the reducing agents.
doi:10.2473/shigentosozai.105.175 fatcat:wgxmg3b4s5gg7b3qkiv6uzzrre