Kinetics of reduction of low grade iron ore by charcoal

Abstract

The reduction of iron ore by solid or gaseous reductant tends to produce a reduction constraint product layer as the normally followed reduction sequence is Fep3 - Fe304 - FeO- Fe. The solid-solid reduction reaction of iron ore with charcoal is relatively slow due to smaller contact area between the particles of iron ore and charcoal. However, the direct reduction of iron ore with charcoal is also dependent on the reduction by carbon monoxide which is so formed at the surfaces of contact betwecn the iron ore and the solid reducant. The present kinetic study on reduction of low grade iron ore used in tribal iron making by charcoal shows very good agreement with Ginstling-Brounshtein model defined as G (ex) = I -2/3 (ex) - (l-ex)213in which diffusion is considered to be the rate controlling step. The activation energy in this diffusion Controlled kinetic study is calculated to be 62.71 Kllmole. Key words: Iron ore. Charcoal reduction. Kinetics, Diffusion, Activation energy.