Reduction Behavior and Mechanism of Iron Ore in Molten Iron in the Process of Converter Steelmaking

Abstract

AbstractXRD and SEM methods were applied to the reduction behavior and mechanism of iron ore in molten iron at temperatures of 1400 °C, 1450 °C, and 1500 °C. The results showed that iron ore could be reduced by carbon in molten iron. When the reduction of iron oxide occurred at the reaction interface, carbon in the molten iron was affected by the concentration gradient. This promoted reduction and the reduction effect improved with increase in reaction temperature. After the carbon in the molten iron almost disappeared, the surfaces of the iron ore and molten iron exhibited oxidizing atmospheres causing different degrees of oxidation of the reduced metal iron and molten iron at 1500 °C. Through analysis of the reduction mechanism of iron ore, it was known that the maximum reaction activation energy during gas phase diffusion was 1612.1 kJ/mol, which restricts the iron ore reduction reaction. At low temperatures, the diffusion of gaseous products in solid-liquid is difficult. Increasing the temperature and stirring accelerate the reduction reaction while increasing gas diffusion.