α-半水石膏的制备与应用研究进展

Research progress on preparation and application of α-calcium sulfate hemihydrate

根据国内外的研究现状,系统介绍了α-半水石膏的结晶特性、制备方法及应用领域。以二水石膏制备α-半水石膏的过程为溶解再结晶的过程,制备方法主要包括蒸压水蒸气法和水热法,分析了上述2种制备方法的优势与不足,水热法中的盐溶液法由于可以加入转晶剂使α-半水石膏向高强度的短柱状晶型转化,该法将随着工艺参数控制方法的完善而得到更为广泛的应用。磷石膏制备α-半水石膏可以大量消耗磷石膏原料,经济上可行,较理想的制备方法为在磷酸和硫酸介质中实现脱水转化。

Crystallization characteristics,preparation and application of αcalcium sulfate hemihydrate were introduced system- atically according to research progress at home and abroad. Process on preparation of α-calcium sulfate hemihydrate by gypsum was a process of dissolution and crystallization. In addition,the preparation methods mainly included autoclave steam method and hydrothermal method. Meanwhile,advantage and shortage of methods above were analyzed. Salt solution method will obtain broader application with the perfectness of parameter control process,due to the fact that the crystal modifier could be added to salt solu- tion in order to make the α-calcium sulfate hemihydrate convert to high intensity short column type crystal. Finally,the ideal technique of α-calcium sulfate hemihydrate prepared by phosphogypsum was put forward, which was,dehydrate converting in phos- phoric and sulfuric acid medium, the major problem of phosphogypsum utilization was economic rationality, in this way,phospho- gypsum would be consumed numerously and the method was economically viable.