Effect of smelting temperature and CO 2 gas flow rate on decarburization kinetics between CO 2 gas and liquid Fe-C alloy

Abstract

The effect of smelting temperature and CO₂ flow rate to decarburization kinetics between CO₂ and liquid Fe-C alloy were investigated. The decarburization rate caused by CO₂ increases with smelting temperature. Compared with low carbon condition (near 0.45 wt pct), the effect of temperature on decarburization rate is more significant under high carbon condition (near 3.5 wt pct). At high carbon content, the decarburization rate increases linearly with CO₂ flow rate. And a CO₂ decarburization kinetics model considering the influence of bubble diameter, bubble generation frequency, rising velocity and rate controlling step was established. When CO₂ transfer in gas phase boundary layer is rate controlling step, the calculated data are in good agreement with the experimental data. It was also found that the effect of CO₂ flow rate on the decarburization rate was mainly affected by the reaction surface area, but less on gas phase mass transfer coefficient in current experimental situations.