The property of carbide slag and the combustion conditions in the circulating fluidized bed boiler(CFBB)have a big influence on the in-furnace desulfurization efficiency and calcium utilization of carbide slag.The effects of carbide slag particle size,reaction temperature and CO2 concentration on the simultaneous decomposition and sulfation of carbide slag were systematically studied and their influence mechanism was analyzed.The results showed that the carbide slag would first undergo a carbonation reaction to produce CaCO3 and then calcined to CaO,which continued to be sulfated.Particle size variation had no significant impact on the desulfurization performance of carbide slag.The desulfurization performance of carbide slag was greatly enhanced under high temperature(850℃,950℃),with calcium utilization up to 80.83%,while the carbonation reaction of carbide slag competed with the sulfation reaction under low temperature conditions(650℃,750℃)and was not conducive to the sulfation reaction.When the CO2 volume fraction was at 55%and 70%,the decomposition of generated CaCO3 was blocked and thus affected the sulfation reaction.However,when the CO2 volume fraction was lower than 35%,although the reaction of carbide slag in the early stage was affected by the concentration of CO2,there was no big difference in desulfurization performance for final CO2 volume fraction of 35%compared with that of 15%.
关键词
电石渣/脱硫/同步分解硫酸盐化/温度/CO2浓度/粒径
Key words
carbide slag/desulfurization/simultaneous decomposition and sulfation/temperature/CO2 concentration/particle size
维普
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