CR PROCESS FOR TREATING COMPLEX TIN DUSTS CONTAINING HIGH ARSENIC AND ANTIMONY
(Central South University of Technology,410083, China)
Abstract: A new process for treating complex tin dusts containing high arsenic and antimony-CR chlorination-drydistillation process(here after, CR process) has been described. The key step of this process is the CR distilling arsenic process in which the tin dusts are leached with a medium concentration hydrochloric acid. A metal or a metallic sulfide is used as a reducing agent to reduce As(V) and Sb(V), and arsenic trichloride is simultaneously distilled from the leaching system. Then arsenic is precipitated for regenerated hydrochloric acid with the sulfide precipitation method. The prominent characteristics of the CR process are of great advantage in removing impurities such as Pb, As, Zn and Sb from the dusts in one step, recovering all valuable elements, eliminating the arsenic harm, and the consequent metallurgy of tin.
Key words: metallurgy of tin chlorination metallurgy distillation arsenic harm