Studies on the reduction of iron oxide with hydrogen

Abstract

Kinetic studies have been carried out on the hydrogen reduction of pure alpha Fe2O3 doped with foreign metal oxides employing a sensinve micro-gravimetric technique. The results show that the reduction of pure Fe2O3 proceeds by a consecutive two-step mechanism via Fe304, the overall rate being controlled by the topochemical reduction of Fe304 while that of doped oxides and hematite ore takes place by a different mechanism involving the mixed ferrite formed. In addition, the reduction of pure Fe203 is catalysed by metal additives in the presence of water vapour. This enhancement in reduction rate ~s attributed to a "hydrogen spill-over" effect.