The influence of CaO on the precipitation behaviour of iron in the reduction of iron oxide

In the present work, the precipitation behaviour of iron in the reduction of pure hematite and 2% CaO contained hematite granules, which were produced by sintering at 1200°C for 6 h, were investigated. Microscopical investigations and specific surface-area measurements on the hematite granules and 2% CaO contained hematite granules, reduced under various reduction conditions, showed that various types of metallic iron form during the reduction of iron oxides, depending on the reduction conditions. While fibrous structure forms during the relatively weak reducing conditions, the homogeneously dense and porous structure forms under strongly reducing conditions for the pure hematite granules. However, the CaO additions were efficient in promoting fibrous iron growth and fibrous iron formation in all reduction conditions.