Volatilization behavior of SnO2 reduced under different CO–CO2 atmospheres at 975 °C–1100 °C

Abstract

The main purpose of this study was to ascertain whether SnO was volatilized or not when SnO2 was reduced in diverse CO–CO2 mixed gases at temperatures above 975°C. The results indicated that tin was inevitably volatilized as gaseous SnO(g) during the reduction process of SnO2 roasted at 975°C–1100°C under different CO–CO2 atmospheres. Roasting temperature and CO content in the CO–CO2 mixed gases obviously affected the tin volatilized fraction. The tin volatilized fraction always increased with the roasting temperature increasing, while it first increased sharply to a maximum value and then decreased slowly to a constant with the increase of CO content from 12.5vol% to 70.0vol% at a certain temperature. SnO2 was readily reduced to SnO(s) and volatilized as gaseous SnO(g) at higher temperatures in weak reductive atmospheres. A small number of newborn metallic tin was in favor of the tin volatilization. In addition, the forming mechanisms of SnO(g) were initially determined under various CO–CO2 atmospheres in this study.