An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modified unreacted core shrinking(MUCS)model were carried out,and the controlling mechanisms of the initial and developing reactions were examined,respectively.From the study of the initial reaction,it was found that the chemical reaction of surface is the controlling step of the overall reaction when the temperature is up to about 750K,while the mass transfer through the gaseous boundary layer dominates the reaction rate when the temperature is above 750K.As the reaction developing within the pellet,the mass transfer through the produced layer becomes the controlling step.In addition,the effects of reaction conditions(such as oxygen concentration,temperature)on the fractional oxidation of magnetite pellet were determined. An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modified unreacted core shrinking (MUCS) model were carried out, and the controlling mechanisms of the initial and developing reactions were examined, respectively. Focus the study of the initial reaction, it was found that the chemical reaction of surface is the controlling step of the overall reaction when the temperature is up to about 750K while the mass transfer through the gaseous boundary layer dominates the reaction rate when the temperature is above 750K.As the reaction developing within the pellet, the mass transfer through the produced layer becomes the controlling step. In addition, the effects of reaction conditions (such as oxygen concentration, temperature) on the fractional oxidation of magnetite pellet were determined.