Abstract: In the desulfurization process of sintering flue gas by dual alkali,the oxidation of desulfurization by-products,calcium sulfite,is an important chemical process.Laboratory experiments were designed for simulating the oxidation process of calcium sulfite.The influencing factors and change law of the oxidation efficiency of calcium sulfite were investigated by changing the reaction time,temperature,initial pH values,stir intensity,air flow and solid content.It was also studied whether manganese ions as a catalyst have effect on the oxidation.The results show that the oxidation of calcium sulfite is dependent on the reaction time,temperature,initial pH values,stir intensity,air flow and solid content,and manganese ions can obviously promote the oxidation of calcium sulfite.The most suitable process conditions were determined.