Study on the Reaction Behavior of CO2 With Molten Steel in Converter Process by Top Blowing Mixed CO2-O2 Gas

In the current study, the reaction mechanism between CO2 and the molten steel during converter process was studied by thermodynamic calculations. Then the industrial trials were carried out in a 300t converter. CO2 reacts with [C] and [Si] simultaneously at the initial stage. CO2 completely reacts with [C] to generate CO at the middle stage. The reaction ratio of CO2 and [C] gradually decreases at the final stage due to the increasing CO2 ratio of reaction with [Fe] and the residual unreacted CO2 respectively. In order to improve the utilization rate of CO2, it is observed that CO2 should be blown into converter during the peak decarburization period, when the blowing time is between 5 and 12 minutes and the [C] content is between 0.7 and 3.3 pct. Comparing the industrial results of CO2 blown with different mixing ratios, the optimum mixing ratio of CO2 gas is found to be 8.1 pct, and the value of [C]*[O] and the content of T center dot Fe in slag are reduced by 1.33 x 10(-4) and 1.27 pct, respectively. The dephosphorization rate is increased by 2.31 pct. The temperature drop is estimated to be 7.6 degrees C/(Nm(3) CO2)/(ton steel).