Effect of smelting temperature and CO2 gas flow rate on decarburization kinetics between CO2 gas and liquid Fe-C alloy

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.

Automated summary

The study investigated the effects of smelting temperature and CO2 flow rate on the decarburization kinetics between CO2 and liquid Fe-C alloy. Results showed that at high carbon content, temperature had a significant impact on the decarburization rate, which increased linearly with CO2 flow rate. The establishment of a CO2 decarburization kinetics model considered various factors influencing the process, with good agreement between calculated and experimental data when the rate controlling step was identified.