压蒸溶液法脱硫石膏制备α-半水装饰石膏实验研究

Experimental Research on Desulfurization Gypsum With Steam Test Solution Method Preparing α-hemihydrate Decorative Gypsum

通过采用蒸压水溶液法,在升温时间为90 min、蒸压温度为130℃的条件下水热处理掺有转晶剂的脱硫石膏浆体制得α-半水装饰石膏晶体,采用体视显微镜观测晶体的形貌特征,利用WA-Y300电子液压机测试抗压强度发现,升温时间过短或过长都不利于强度的提高,只有在α-半水装饰石膏晶体析出的饱和度与生长速率达到动态平衡时最佳;蒸压时间以转晶最充分时为宜,此时强度最高;浇注时间应控制在α-半水装饰石膏水化之前,浇注温度可略低于蒸压温度.因此脱硫石膏浆体采用高温法制取α-半水装饰石膏浆体的工艺是可行的,升温时间应控制在90 min,6 h蒸压抗压强度最高可达到34.8 MPa,α-半水装饰石膏浆体浇注时间应在2 min左右,浇注温度在120℃时最为合适.

Pressure solution method and high temperature method are used to hydrothermal treatment desulfurization gypsum which is added crystal modifier preparing crystal α-hemihydrate decorative gypsum in the condition when the heating-up time is 90 min,and the autoclaved temperature is 130 ℃.The stereomicroscope and the WA-Y300 electronic hydraulic press are used to measure the morphology features and the compressive strength.The result demonstrates that when the heating-up time is too short or too long,it is not conducive to the improvement of strength.Only when saturation precipitated by α-hemihydrate decorative gypsum and growth rate reaches equilibrium,it is the best.When the autoclaves time is the best,the crystal transformation is most sufficient.And at this point the strength is the highest.Pouring time should be controlled in the time before α-hemihydrate decorative gypsum hydration,and the pouring temperature can be slightly lower than the autoclave temperature.The process of desulfurization gypsum preparing α-hemihydrate decorative gypsum by high temperature method is feasible.Heating-up time controlled within 90 min,6 h autoclaved compressive strength is up to 34.8 MPa.α-hemihydrate decorative gypsum paste pouring time should be about 2 minute and pouring temperature at 120 ℃ is the best.