高温对粉煤灰表面解聚作用研究

Study of effect of high temperature on depolymerization of fly ash's exterior structure

通过硅铝质胶凝材料高温增钙改性的优化方法,应用电子显微镜(SEM)、核磁共振(NMR)、傅里叶红外光谱(FTIR)等测试手段研究了改性粉煤灰硅铝网络结构的解聚机理与规律.结果表明:高温增钙使粉煤灰表面部分Si-O键断裂,导致高配位的网络中间体Al及Ca较多渗入,网络结构部分强峰的化学位移向低场移动,网络结构聚合度降低,化学活性明显提高.最终优化的高温增钙粉煤灰配比为CFA-4-1 200℃,即81.0%LCFA1+15.0%CaO+3.0%石膏+1.0%萤石,温度制度为1 200℃下0.5 h.

Though optimization method of calcium addition at high-temperature on cementing material made of silicon-aluminum,the depolymerization mechanism and law of silicon-aluminum network structure of modified fly ash were studied using scanning electron microscope（SEM）,scanning electron microscope（NMR）,fourier transform infrared spectrometer（FTIR）.The results show that the Si-O chemical bond of modified fly ash＇exterior structure was broken,which led to high infiltration of intermediate such as silicon and aluminum.The part of network structure＇s strong peaks chemically shifted to low field.The network structure＇s polymerization became lower,and its chemical activity became better.Finally optimization ratio of modified fly ash is CFA-4-1 200 ℃,i.e.81.0% LCFA ＋15.0% CaO ＋3.0% gypsum ＋1.0% fluorite at 1 200 ℃ for 0.5 hours.