Abstract: The feasibility of separation of impurities in refined bismuth and reagent deleadization with vacuum distillation is studied theoretically.Experimental studies on reagent deleadization were carried out in vacuum and the influence of various factors,including amount of reagent,distillation temperature,vacuum degree and distillation time on the deleadization are inspected;then an optimal technical condition is achieved to be the following: as to sulphur deleadization,addition of sulphur is about 0.02 g/g of refined bismuth,at distillation temperature of 1 073 K,lead content in refined bismuth decreases from 3.0×10^-5 to 2.1×10^-7,and the deleadization rate is about 99.3%;as  to chloridized deleadization,addition of copper chloride is about 0.06 g/g of refined bismuth,at distillation temperature of 1 023 K,lead content in refined bismuth decreases from 3.0×10^-5 to 2.4×10^-7,and the deleadization rate is about 99.2%.Other impurities in refined bismuth can be also removed effectively under certain conditions,the content of bismuth has reached the level of “99.999%”with vacuum distillation.

Key words: vacuum distillation；reagent, deleadization, metal bismuth；High-purity