Development and Application of Converter COMI-B Technology: A New Way of CO2 Utilization

Abstract

CO2 has characteristic properties and reactions at the converter smelting temperature, and the chemical reaction between CO2 and elements such as C and Si in the molten pool has bubble proliferation and cooling effects, which can effectively improve the kinetic and thermodynamic conditions of converter smelting. Here, an experimental study and industrial test on the application of CO2 in converter smelting were carried out. The smelting effects of Mode-1 and Mode-2 with total CO2 injection amounts of 229 Nm3 and 196 Nm3, respectively, were compared, and the changes in molten steel and slag compositions, dust removal, and gas were analyzed. The test results show that converter top and bottom blowing CO2 technology (COMI-B) technology had significant metallurgical advantages over the N-Mode; the dephosphorization rate increased by 4.2%, slag (FeO) content was reduced by 2.04%, end point nitrogen content of molten steel was reduced by 20%, gas recovery increased by 8.29 Nm3/t, and soot production was reduced by 14.7%. The results of the study provide a reference for the application of COMI-B technology in converters in the iron and steel industry and develop a new path for resource utilization of CO2.