Abstract: Experiments were performed to deoxidize phosphogypsum by a compound reducing agent, a mixture of high-sulfur coal and coal gangue. The effects of compound reducing agent formulation，compound reducing agent size, C/S molar ratio, and reaction temperature on the concentration of SO2 in furnace gas，the decomposition rate of CaSO4 in phosphogypsum and the desulfurization rate were studied. The results demonstrated that the concentration of SO2 in furnace gas was over 16.02%，the decomposition rate of CaSO4 was over 95% and the desulfurization rate was over 90%.

摘要： 采用高硫煤与煤矸石制备成复合还原剂还原分解磷石膏，研究了还原剂配方及粒度、C/S值（物料中C与S的摩尔比值）、反应温度对炉气二氧化硫浓度、磷石膏CaSO4分解率和脱硫率影响。结果表明：二氧化硫浓度可达16.02%，磷石膏中CaSO4分解率大于95%，磷石膏脱硫率大于90%，能为制酸提供合格的原料气和为制水泥提供合格的原料。