Kinetics of iron oxide reduction using CO: Experiments and Modeling

Abstract

Reduction of iron ore is central to iron and steel making process. The reaction kinetics are generally studied using classical models that are based on the mechanism of interface control, nucleation control, or diffusion control. This paper presents a different approach in which physical governing equations for the solid phase are solved simultaneously with the gas phase transport equations. The reaction rate is calculated using shrinking core model and the parameters for kinetic term are estimated using genetic algorithm. The model is validated using data collected from experiments performed using iron ore pellets in a packed bed reactor and iron ore powder in a TGA apparatus. The reduced samples are subjected to SEM analysis to observe the microstructural changes that occur as a result of high temperature reduction. The paper further discusses, the applicability of the classical models in describing the different stages of reduction.