Production of SO2 and lime from phosphogypsum reduced With lignite in a nitrogen atmosphere

In this study, using lignite as a reducer, the reaction characteristic of the reduction decomposition of phosphogypsum to SO2 and lime was investigated in a nitrogen atmosphere at different conditions. Scanning electron microscopy and XRD-ray diffraction were used to analyze the solid production. The gas production of SO2 was analyzed by the Gas Analyzers. The experiment results showed that the optimal conditions for production of SO2 are founded to be a molar proportion of C:CaSO4=0.8:1 and a decomposition temperature of over 1000 degrees C.Under these conditions the maximum concentration of SO2 reached to 8.23% (vol. %). The CaO content of solid production increased to 62.57%. The desulfurization rate of phosphogypsum reached to 95.16%.