Abstract: Efficient and economical desulfurization is the key to realize the comprehensive utilization of desulfurization gyp?鄄sum through the chemical circulation of calcium oxide and the acidification from flue gas.The effects of carbon content，Fe2O3 content and temperature on gypsum decomposition and desulfurization rate were systematically studied by thermogravimetry?鄄mass spectrometry（TG-MS） combined with tube furnace roasting experiments and by means of XRD and XRF.The resultsshowed that the addition of carbon and Fe2O3 in gypsum could effectively decrease the decomposition temperature of gypsum and increase the decomposition rate of gypsum under argon atmosphere.The carbon content，Fe2O3 content，and calcination temperature had different action intervals for gypsum decomposition.The decomposition rate and the desulfurization rate of the gypsum both reached the maximum with mixing low content of carbon under high temperature.while the temperature was above 1 200 ℃，the effect of temperature increase on the desulfurization rate was gradually disappeared.With the increase of carbon content，the desulfurization rate and decomposition rate decreased significantly，the decomposition temperature decreased，and the total reaction time decreased.By adding Fe2O3，there was a decrease in the decomposition temperature of gypsum，while the decomposition rate and the desulfurization rate increased.Under the experimental conditions，in order to increase the desulfurization rate and obtain more calcium oxide，the appropriate temperature， the amount?鄄of?鄄substance ratio of C to CaSO4 and the dosage amount of Fe2O3 should be 1 100 ℃，0.8 and 10%， respectively.

Key words: gypsum, iron oxide, carbon, decomposition rate, desulphurization rate