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 degrees C The results indicated that tin was inevitably volatilized as gaseous SnO(g) during the reduction process of SnO2 roasted at 975 degrees C-1100 degrees 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 12.5 vol% to 70.0 vol% 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. (C) 2015 Elsevier B.V. All rights reserved.