2020 Volume 60 Issue 5 Pages 848-855
In order to clarify the role of O2 and CO2 which are applied to steelmaking, the isotope tracing method has been used to study the decarburization reactions between CO2–O2 mixed gas and Fe–C melts containing different carbon contents at 1873 K. When the mixture of two isotope gases of 18O2 and 13CO2 reacts with melts, the isotopic composition of the reacted gas is monitored online by a mass spectrometer. According to the change of isotopic gas composition, the ratio of various reactions and the decarburization rate can be calculated, and the effects of gas flowrate and carbon content on the decarburization reaction can be discussed. The results showed that the utilization of CO2 was more than 97%, and approximately 52% of oxygen formed to CO, 17% to CO2, and 31% for post combustion under the conditions of 30 ml/min of flowrate, 1 cm of the gas injection height and the 4.00 to 1.00 wt% of original carbon content. And with the increase of the flowrate from 30 ml/min to 40 ml/min, the amount of CO2 generated by O2 increased, while the amount of CO decreased. In particular, the post combustion ratio improved significantly from 47% to 77%.