Induration process of oxidized pellets involves the oxidation of Fe_3O_4 and re-crystallization of Fe_2O_3.The oxidation process of Fe_3O_4 is significant for pellets to obtain better ambient strength.Thus,the effect of MgO on oxidation process of Fe_3O_4 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 Fe_3O_4.The oxidation rate of Fe_3O_4 in MgO-fluxed pellets(95.0% Fe_3O_4 +5.0% MgO)is slower than that in standard acid pellets(100% Fe_3O_4).The relation between oxidation ratio of Fe_3O_4 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. Induration process of oxidized pellets involves the oxidation of Fe_3O_4 and re-crystallization of Fe_2O_3. The oxidation process of Fe_3O_4 is significant for pellets to obtain better ambient strength. Thus, the effect of MgO on oxidation process of Fe_3O_4 was investigated. Unreacted core model was applied to analyze the oxidizing results in the pellets. The experimental results show that MgO plays a negative role in the oxidation process of Fe_3O_4. The oxidation rate of Fe_3O_4 in MgO-fluxed pellets (95.0% Fe_3O_4 + 5.0% MgO) is less than that in standard acid pellets (100% Fe_3O_4). The relation between oxidation ratio of Fe_3O_4 and time was calculated based on the unreacted core model for both MgO-fluxed pellets and standard acid pellets. Accccording 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.