Effect of MgO on Oxidation Process of Fe3O4 in Pellets

Induration process of oxidized pellets involves the oxidation of Fe3O4 and re-crystallization of Fe2O3. The oxidation process of Fe3O4 is significant for pellets to obtain better ambient strength. Thus, the effect of MgO on oxidation process of Fe3O4 was investigated. The unreacted core model was applied to analyze the oxidizing induration process of pellets. The experimental results show that MgO plays a negative role in the oxidation process of Fe3O4. The oxidation rate of Fe3O4 in MgO-fluxed pellets (95.0% Fe3O4 +5.0% MgO) is slower than that in standard acid pellets (100% Fe3O4). The relation between oxidation ratio of Fe3O4 and time was calculated based on the unreacted core model for both MgO-fluxed pellets and standard acid pellets. According to verification experiments, the values calculated by model coincide well with the experimental values. Therefore, the unreacted core model could be applied to describe the oxidizing induration process of pellets.