Non-isothermal Reduction Kinetics of Iron Ore Oxygen Carrier by CO with Variable Activation Energy Model

The carbon emissions from blast furnace ironmaking are extremely significant. According to the carbon loss in blast furnaces, increasing indirect reduction is the primary solution to this issue. However, its kinetic behavior remains unclear, hindering energy-saving and carbon reduction efforts in blast furnaces. Consequently, this study conducted reduction experiments on sinter and coke under simulated blast furnace conditions. A variable activation energy model (IR-VAEM) for the reaction between CO and iron ore was established based on a combination of the unreacted shrinking core model and the concept of variable activation energy. The conclusion is as follows: The variable activation energies of sinter ranged from 61.92 to 91.23 kJ/mol, and the pre-exponential factor was 0.26. The control mechanism involves transitioning from interfacial reactions to the internal diffusion of reaction gases. The deviation analysis revealed that the predicted values obtained from IR-VAEM deviated from the experimental values by 1.06 pct. It provides a theoretical foundation for promoting the rational utilization of coke resources in blast furnace ironmaking and reducing carbon emissions.