Reaction Behavior of Ultrafine Ferric Oxide Powder with Hydrogen-Carbon Monoxide Gas Mixture

This study aims to enhance fundamental research on the reaction behavior between ferric oxide and H₂-CO gas mixtures and to provide theoretical support for optimizing the injection of hydrogen-containing materials in the ironmaking process. In this study, the ultrafine ferric oxide powder was isothermally reduced with H₂-CO gas mixture at 1023 K-1373 K. The results indicated that when H₂ content is less than 30% at 1023 K, the ferric oxide sample reduced by the H₂-CO gas mixture exhibits a pronounced carbon deposition phenomenon during the reduction stage. The gas reactant composition had a relatively large influence on the reaction rate at the third stage of the reduction reaction (FeO → Fe). Assuming the single-step nucleation assumption theory together with kinetic experimental data, the relationship between the average reaction rate and the gas composition of the H₂-CO gas mixture was established for the FeO reduction stage. In addition, the apparent activation energy of the reduction reaction was generally in the range of 20-45 kJ/mol, indicating that the possible rate-controlling step was combined gas diffusion and interfacial gas-solid chemical reaction.