Clean and efficient separation process for high-antimony crude tin

Abstract

Antimony circulates in a tin refining system, which strongly affects the production process. In this study, continuous vacuum separation and discontinuous vacuum separation processes were developed for high-antimony crude tin (HACT). During the industrial treatment of 60 t of HACT, product I of crude Sn and Sn–Sb alloy I were obtained by continuous vacuum separation at a temperature of 1473 K and pressure of 20–100 Pa. Then, Sn–Sb alloy I produced crude Sb and Sn–Sb alloy II via intermittent vacuum separation at 1273 K and 20–150 Pa. Finally, Sn–Sb alloy II was subjected to intermittent vacuum separation without adding any reagents, which generated no waste gas or water. The direct yields of Sn and Sb were 72.99% and 71.15%, respectively, while the total power consumption of the described process was as low as 1086 kWh/t, which were superior to the corresponding parameters of other treatment processes. This paper reports a novel clean and efficient HACT industrial treatment method with an open Sb circuit from the Sn refining system.