Effects of Intrinsic Carbon and Gangue Oxides on Heating and Melting Behavior of Hot Briquetted Iron: Implications for Green Steel Production in Electric Arc Furnace for CO2 Mitigation
摘要
We investigated the effects of intrinsic carbon and gangue oxides in hot briquetted iron (HBI) on its heating and melting behavior for the applications to the electric arc furnace (EAF) process. Various phenomena such as CO gas evolution and slag production by gangue oxides in HBI were experimentally observed at each reaction step. Using the Coats-Redfern method, the average activation energies for the non-isothermal reduction values of Fe3O4 and FeO were ca. 128 and 260 kJ/mol, respectively. Kinetic analysis confirmed that Fe3O4 reduction follows one-half-order kinetics, whereas FeO reduction follows second-order kinetics. The thermodynamic behaviors of oxygen and carbon were strongly dependent on HBI chemistry. Therefore, both the carbon in liquid steel and the slag composition must be controlled to optimize EAF operation with active use of HBI for the mitigation of CO2 emissions.