Abstract: High purity metal lanthanum was applied to integrated circuits, hydrogen storage cells, and luminescent materials. Common impurities, like Fe, Si, Ni, hardly removed by the popular preparing method of vacuum distillation, could be removed by zone refining. In this paper, the impurity redistribution of Fe, Si, and Ni in lanthanum during the process of zone refining was studied. The impurity distribution curves calculated by the mathematical model were fit well with that of experimental result and the curve’s fitness was more than 0.94.Meanwhile, after multiple zone refining distributions, the removal rate of Fe, Si, Ni reached to 99%, 93%, and 92% respectively. With the increase of zone refining passes, the removal rates of Fe, Si and Ni can reach 99%, 93% and 92% respectively. After 18, 16, and 14 zone refining passes for Fe, Si and Ni, purification effect is not obvious with the increase of zone refining passes.
Authors: Ke Xu, Siming Pang, Shihong Yan, Hongbo Yang, ZhiqiangWang, Dehong Chen, Daogao Wu, and Lei Zhang
Keywords: zone refining, lanthanum metal, impurity distribution, purification