Application of vacuum distillation technology to purification of low melting point metals

Vacuum distillation method is considered to be one of the most important purification methods on metals, especially low melting point metals, because of its short process, less consumption, environmental pollution and other advantages. The present situation and progress of vacuum distillation technology in high purity metal purification are described in detail. The technique of vacuum distillation fractionation mechanism and influencing factors which includes saturated vapor pressure, partition coefficient and the evaporation rate are introduced. The vacuum distillation technology used in the low melting point metal bismuth, stibium, indium purification and the feasibility of using a variety of methods to purify ultra -high purity metals are discussed. Super high purity bismuth (>99.999 9 %) is prepared through the process of combining vacuum distillation with zone melting purification.