Investigation on the characteristics and kinetics of isothermal reduction of hematite under simulated coke oven gas atmosphere in rotary bed reactor

The effect of H-2-CO ratio, reduction temperature and time on the reduction degree, mineral phase, and morphology of the reduced production was investigated in this study by reducing hematite with coke oven gas (COG) as the reducing agent to alleviate the pressure from the increasing demand of iron ore. The kinetics analysis, reduction mech-anism, and deposited carbon behavior were proposed. The results revealed that the reduction degree reached the maximum value of 94.69% at the temperature of 900 degrees C for 10 min in a simulated COG atmosphere. At 800 degrees C, the pores and cracks on the surface of the particle became more and wider as the reaction time increased. When the reaction time reached 30 min, massive Fe3C was attached to the surface, and the newly formed spherical metallic irons were bonded to each other and randomly distributed on the surface of the product particles. Besides, the deposited carbon mainly existed in two forms of a rough porous structure and cluster structure when the temperature increased to 900 degrees C. The hematite reduction process was mixed-controlled by one-dimensional diffusion re-action and three-dimensional interfacial reaction, and the activation energy decreased to 50.79 kJ/mol. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.