Preparation of high-purity bismuth by sulphur deleadization in vacuum distillation
(1. College of Chemistry and Chemical Engineering, Jishou University,
Jishou 416000, China;
2. College of Materials and Metallurgical Engineering,
Kunming University of Science and Technology, Kunming 650093, China)
Jishou 416000, China;
2. College of Materials and Metallurgical Engineering,
Kunming University of Science and Technology, Kunming 650093, China)
Abstract: The feasibility of separation of impurities in refined bismuth and sulphur deleadization with vacuum distillation was studied theoretically. Experimental studies on sulphur deleadization were carried out under vacuum. The influences of amount of sulphur, distillation temperature, vacuum degree and distillation time on deleadization were investigated and an optimal technical condition was achieved. The content of lead in refined bismuth can be decreased from 30μg/g to 0.21μg/g, which has reached the level of “5N” high-purity bismuth. Other impurities in refined bismuth can be also removed effectively under certain conditions.
Key words: vacuum distillation; sulphur deleadization; refined bismuth; high-purity bismuth