常压盐溶液法制备α-半水石膏的工艺参数研究

Study on The Process Parameters of Preparation of α-Plaster of Paris by Aqueous Salt Solution Method in Atmospheric Pressure

二水石膏在盐介质中部分脱水可制得高强度α-半水石膏.采用单因素实验考察了媒晶剂、盐介质、洗涤水温度、产品干燥温度、产品粒度等因素对常压盐溶液法制备α-半水石膏的抗压强度的影响,实验结果表明:当媒晶剂为柠檬酸钠与Al3 + 等的复合物(占盐溶液的质量百分比为1.0 % )、盐介质为15 % (质量百分比)的KCl水溶液、洗涤水温度在98℃以上、产品干燥温度为110 - 130℃、产品粒度控制在7- 4 μm时,产品抗压强度可达4 4MPa .

High-strength α-plaster of Paris can be produced by dehydrating gypsum dihydrate partially in aqueous salt solution. Single factor test was employed to investigate some factors effecting the compressive strength of hydratedα-plaster of Paris which was made by Aqueous Salt Solution Method in atmospheric pressure such as crystal modifiers,aqueous salt solution,emperature of water to washα-hemihydrate gypsum powder,product drying temperature,product grain size. The results of these experiments were as follow: crystal modifier was the mixture of citric acid (or its salt) , Al3+ and other substance and the mass percentage of the mixture was 1.0% (in aqueous salt solution), the aqueous salt solution was 15%KCl (mass percentage), temperature of water to washα-hemihydrate gypsum powder was over 98℃, product drying temperature was in the range of 110-130℃, product grain size was controlled in 7-4μm. Under these conditions above-mentioned, compressive strength of product could reach 44 Mpa.