The reduction and carburization behavior of vanadium titanomagnetite pellets in gas-based shaft furnace is critical for enhancing the smelting efficiency of vanadium titanomagnetite. The effects of CH4, H2O and CO2 on the metallization rate, cementite (Fe3C) content and free carbon content of direct reduced iron (DRI) were investigated under a simulated gas-based shaft furnace atmosphere (H2-CO-CH4-H2O-CO2-N2). When the CH4 content is in the range of 3% to 9% and the CO2 content is within 0% to 5%, the metallization rate of DRI consistently exceeds 91.90%. As the H2O content increases from 0% to 5%, the metallization rate of DRI varies between 89.21% and 95.36%. The contents of Fe3C and free carbon increase as the CH4 content increases and the H2O and CO2 content decrease. When the CH4 content exceeds 7%, the cementite content surpasses 21.75%. Besides, the microscopic and macroscopic characteristics of the DRI were also analyzed using a digital microscope and a scanning electron microscope in this paper.
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