石灰石-石膏法烟气脱硫系统处理废稀硫酸

采用石灰石-石膏法脱硫装置处理废稀硫酸。研究了石灰石浆液和废稀硫酸的不同投加顺序以及不同反应晶种(石膏浆液、石膏稀浆液)对所得石膏晶粒形态和抽滤物含水率的影响。试验结果表明:与废稀硫酸加入石灰石浆液的方式相比,石灰石浆液加入废稀硫酸的方式更利于石膏结晶,晶粒更大,所得石膏抽滤物含水率更低;以石膏浆液和石膏稀浆液作为反应晶种,抽滤物含水率可分别达到13.2%和14.1%,适宜的晶种浆液与总反应液的体积比为1/3。实际验证结果表明,该工艺对现有脱硫系统没有影响,石膏产物一并处理,且为脱硫系统提供了补充水,经济效益和环境效益显著。

Treatment of spent dilute sulfuric acid in fuel gas desulfurization system by using limestone-gypsum method

The spent dilute sulfuric acid was treated in fuel gas desulfurization (FGD) system by using limestone-gypsum method.The effects of different adding sequences of limestone slurry and dilute sulfuric acid and different reaction crystal seeds (gypsum slurry and dilute gypsum slurry) on grain morphology of gypsum product and the water content of filtered residue were studied.The experimental results show that:Compared with the way of adding dilute sulfuric acid into limestone slurry,it is found that the way of adding limestone slurry to dilute sulfuric acid is more conductive for gypsum crystallization,with larger grains and lower water content of filtered gypsum;Using gypsum slurry and dilute gypsum slurry as reaction crystal seeds,the water content of filtered gypsum is 13.2% and 14.1% respectively,and the suitable volume ratio of crystal seed slurry to total reaction solution is 1/3.The actual verification results show that this process has significant economic and environmental benefits with advantages of no negative affection on the current FGD system,gypsum products being treated together,and can provide supplementary water for FGD system.