Hybrid Reduction of Iron Ores by Biomass and Hydrogen Gas: Reduction Behavior

Biomass and H 2 are characterized as environment‐friendly, and can be used as reductant in the reduction process of iron oxides, therefore to achieve carbon neutrality of the shaft furnace direct reduction ironmaking process, and meanwhile produce carbon‐containing direct reduced iron (DRI). For the synergistic utilization of biomass and H 2 , this study used H 2 to reduce biomass embedded self‐reducing pellets (SRP) to produce DRI. The relative mass loss ratio, reduction degree and metallization degree, and microstructure of pellets reduced under different conditions (750–950 °C, CO involved, H 2 involved and N 2 atmosphere) are analyzed to clarify the reduction behavior of torrefied biomass‐ and charcoal‐embedded pellets. Results indicate that higher temperature, H 2 involved atmosphere, and higher embedded biomass content favors the hybrid reduction of iron oxides; addition of biomass affects the reduction efficiency of pellets from two aspects, porosity and solid carbon reduction. Under the optimal reducing condition (950 °C and 40% H 2 %–60% N 2 atmosphere), reduction degree of 87% can be achieved by reducing torrefied biomass embedded SRP, and DRI with acceptable carbon content is expected be produced.