脱硫石膏制备硫酸钙晶须的试验研究

以脱硫石膏为原料通过水热合成法制备硫酸钙晶须,借助X射线衍射仪、扫描电子显微镜、能谱仪、热重分析仪等测试手段进行分析,研究了酸化预处理、料浆浓度以及反应温度对制备硫酸钙晶须的影响。结果表明:酸化预处理可以有效去除原料中的CaCO₃杂质;随着料浆浓度和反应温度的增加,晶须长径比均呈现先增大后减小的趋势;当料浆浓度为3%(质量分数),pH值为6.5,反应温度为120 ℃,反应时间为2 h时,取得的硫酸钙晶须最佳平均长度为161.2 μm,最佳平均长径比为46.06。

Preparation of Calcium Sulfate Whiskers from Desulfurized Gypsum

Calcium sulfate whiskers were prepared by hydrothermal synthesis method with desulfurized gypsum as raw material. The effects of acidification pretreatment, slurry concentration and reaction temperature on the preparation of calcium sulfate whiskers were studied by X-ray diffractometer, scanning electron microscope, energy spectrometer, thermal gravimetric analyzer and other test methods. The experimental results show that the acidification pretreatment effectively removes CaCO₃ impurities in raw materials. As the slurry concentration and reaction temperature increase, the aspect ratio of whisker increases first and then decreases. When the slurry concentration is 3%(mass fraction), the pH value is 6.5, the reaction temperature is 120 ℃ and the reaction time is 2 h, calcium sulfate whiskers achieve the best average length of 161.2 μm, and the best average aspect ratio of 46.06.