用硫酸溶液制备石膏的试验研究

Experimental research on preparation of gypsum with sulfuric acid solution

采用硫酸溶液和碳酸钙制备了二水石膏,研究了不同浓度的转晶剂和硫酸对生成的二水石膏形貌、颗粒大小和游离水含量的影响规律。结果表明,转晶剂柠檬酸浓度为0.01~0.12 mol/L,硫酸浓度为50~200 g/L时,制得的二水石膏形貌呈菱形薄板状,中位径为24~36μm,石膏游离水含量为18.9%~28.0%。采用此二水石膏制备的建筑石膏其2 h抗压强度可达到5.0 MPa,2 h抗折强度达到2.5 MPa。

Dihydration gypsum is prepared with sulfuric acid solution and calcium carbonate,the influence law of crystal habit modifier and sulfuric acid with different, concentration on the morphology, particle size,and free water content was investigated. The results show that：when citric acid concentration is 0.01 to 0.12 mol/L and sulfuric acid solution concentration is 50 to 200g/L,the obtained dihydration gypsum morphology is of diamond plate,the mean diameter distribute is 24 to 36 μm,and the free water content changes from 18.9% to 28.0%. And the 2 h compressive strength and 2 h flexural strength of the building gypsum produced with this dehydration gypsum can reach 5.0 can and 2.5 MPa respectively.