Removal of Arsenic from Crude Tin by Vacuum Distillation

Abstract

Arsenic is widely present in the process of ore-dressing, tailings recovery and smelting, which is poisonous and harmful. Current technologies which can treat tin ore or crude tin have not achieved satisfactory economic and environmental effects. In particular, the existing processes have poor effects on arsenic removal from raw materials. This paper adopted vacuum distillation to deal with crude tin. In the experimental research, tin was left as a residue after the distillation, and arsenic was volatilized into the gas phase as a volatile. The impurities in crude tin were effectively removed at 1473 K for 35 min and material weight of 80 g under 5 Pa. Under this condition, 98.67 mass% of tin in the residue can be recovered, and 84 mass% of arsenic in crude tin was removed by vacuum distillation. Arsenic can be removed effectively from crude tin by using vacuum distillation.