CO2 injection into blast furnace tuyeres is a new technology to utilize CO2, aiming at expanding the way of CO2 self-absorption in metallurgical industry. In this paper, a mass and energy balance mathematical model is used to analyze the variation of smelting parameters after CO2 injection. Moreover, an industrial test of injecting CO2 into the blast furnace tuyeres performed in a 1780m3 blast furnace. Theoretical analysis and industrial tests show that this technology is feasible, simultaneously, the hot blast consumption per ton of iron is reduced and the heat value of the gas on the top of the furnace is increased. The endothermic reaction between CO2 and carbon leads to the redistribution of heat in the blast furnace, When the injection rate is more than 1%, marginal gas developed, affecting the smooth operation of the blast furnace.
Keywords: blast furnace, CO2, smelting parameters, mathematical model