Kinetics of Reduction of Composite Pellets Containing Iron Ore and Carbon

AbstractThe effects of temperature, pellet type, inert and reactive gas flowrate, and external atmosphere on the reduction rates of composite pellets containing iron ore and coal or coke were investigated in the temperature range 900–1200°C. Two different pellets were reduced in N2 atmosphere. Experiments were also conducted for one of the pellets in CO and in CO2 atmospheres. The conversions were obtained by the fraction of oxygen removed from the pellets, calculated from gas analysis. It was observed that with increasing temperature, decreasing the N2 flowrate and utilizing CO atmospheres, the reaction rate increased. The Boudouard reaction is likely to control the solid reduction for both pellets, at the temperatures investigated. A well-known kinetics equation successfully represented most of the experimental data and allowed the evaluation of the rate constants. The pre-exponential factors and activation energies were determined by the Arrhenius equation. Resume Les effets de la temperature, du type ...