化工企业脱硫石膏重结晶法制备硫酸钙晶须研究

Study on the Preparation of Calcium Sulfate Whiskers by Desulfurization Gypsum Recrystallization of Chemical Enterprises

化工厂在处理SO2废气时通常会采用湿法处理,由于湿法脱硫后产生的脱硫石膏产量巨大利用较为困难,所以在本篇文章中用化工厂产生的固废脱硫石膏为原料,重结晶法制备二水硫酸钙晶须,进行探讨了不同的条件对于硫酸钙晶须样貌的影响,利用扫描电子显微镜与X射线衍射仪、白度仪对二水硫酸钙晶须的物理特性进行表征与分析。并对反应中使用的酸性母液进行循环探究最经济的工艺处理方案。通过实验得到重结晶法制备二水硫酸钙晶须的最佳条件为:H2SO4浓度为2 mol/L,过饱和度为1,反应时间为1 h,反应温度为80℃,降温区间为80~20℃,陈化时间为8 h,在最佳情况下合成的二水硫酸钙晶须平均长度为290μm,平均长径比为67,白度为93.5,产率为47%。

Chemical plants usually use wet process to treat SO2 waste gas.Since the desulfurized gypsum produced by wet process desulfurization has a huge output and is difficult to use,in this paper,solid waste desulfurized gypsum produced by chemical plants is used as raw material to prepare calcium sulfate dihydrate whisker by recrystallization,and the influence of different conditions on the appearance of calcium sulfate whisker is discussed.The physical properties of calcium sulfate dihydrate whisker were characterized and analyzed by scanning electron microscope,X-ray diffractometer and whiteness meter.And the acid mother liquor used in the reaction was recycled to explore the most economical process treatment scheme.The optimum conditions for preparing calcium sulfate dihydrate whisker by recrystallization method are as follows:When the concentration of H2SO4 was 2 mol/L,the susaturation was 1,the reaction time was 1 hour,the reaction temperature was 80℃,the cooling interval was 80~20℃,and the aging time was 8 h,the average length of calcium sulfate dihydrate whiskers was 290μm,the average aspect ratio was 67,the whiteness was 93.5,and the yield was 47%.