Low Emission Sponge Iron Production in RHF: A CFD Study

Recycling iron-bearing solid wastes generated during iron and steelmaking processes is crucial for optimizing resource utilization and mitigating carbon emissions. The Rotary Hearth Furnace (RHF) has emerged as a promising alternative for sponge iron production from solid waste. This study developed a 3D computational fluid dynamics (CFD) model of a pilot-scale RHF using the FLUENT solver to investigate use of hydrogen as a fuel. The results indicated that substituting hydrogen for hydrocarbon-based fuels led to a remarkable reduction in fuel and air consumption, resulting in increased profitability for direct reduced iron (DRI) production. Optimum conditions for post-combustion of CO, air, and fuel rate and their preheat temperature were identified to minimize fuel rate and emission, maximizing heat transfer to pellet bed, and maintaining a reducing atmosphere over pellet bed to restrict reoxidation of metalized pellet with hydrogen as heat-producing fuel.