Abstract
It was tried by observing partially reduced pellets microscopically and by analysing reduction rates to elucidate the mechanism for Al2O3 to accelerate the reduction of wustite produced from magnetite containing Al2O3. A macroscopical cross section view of partially reduced pellets of 50% reduction indicates that the reduction pattern is of homogeneous type except the one at 1203 K. Furthermore, the microscopical observation displays that wustite grains are covered by a dense layer of metallic iron and that the mean radius of residual wustite grains decreases with an increase in the amount of Al2O3. On the other hand, a graphical analysis of reduction rate shows that the rate is controlled by the diffusion of oxygen in a metallic iron layer covering wustite grain. From the above mentioned results, it is concluded that the effect of Al2O3 may cause the formation of the dense iron layer covering the wustite grain thoroughly, but it can accelerate the reduction by dividing a wustite grain into smaller many ones.
