常压无氯盐溶液制备α-CaSO_(4)·0.5H_(2)O晶体研究

Preparation of α -CaSO_(4) ·0.5H_(2) O Crystals from Chlorine-Free Salt Solution at Atmospheric Pressure

本文以Na_(2)SO_(4)溶液为反应介质,研究了反应温度、反应时间、液固比、pH值、Na_(2)SO_(4)质量分数对α-CaSO_(4)·0.5H_(2)O生成的影响。结果表明,在Na_(2)SO_(4)质量分数为12.5%,液固比为5∶1,pH值为7,反应温度为97℃,反应时间为4 h的条件下,制备出平均长度46.0μm、平均长径比17.23、形貌均一的α-CaSO_(4)·0.5H_(2)O晶体。常压无氯盐溶液方法克服了氯离子腐蚀工业设备、污染环境等缺点,为高值化利用磷石膏提供重要的技术支持。

The effects of reaction temperature,reaction time,liquid-solid ratio,pH value and Na_(2) SO_(4) mass fraction on the generation ofα-CaSO_(4)·0.5H_(2) O were investigated using Na_(2) SO_(4) solution as the reaction medium.The results show thatα-CaSO_(4)·0.5H_(2) O crystals with an average length of 46.0μm,an average aspect ratio of 17.23 and a homogeneous morphology are prepared under the conditions of Na_(2) SO_(4) mass fraction of 12.5%,liquid-solid ratio of 5∶1,pH value of 7,reaction temperature of 97℃and reaction time of 4 h.The method of chloride-free salt solution under atmospheric pressure overcomes the drawbacks of chloride ion corrosion of industrial equipment and environmental pollution,providing important technical support for the high value utilization of phosphogypsum.