活化煤矸石地质聚合物的制备与性能研究

对原状煤矸石进行了定性和定量双重分析,优化了煤矸石活化的煅烧温度,探究了钠铝比(n(Na)/n(Al)=0.52、0.57、0.62)和激发剂模数(M=0.66、0.69、1.32、1.65)对活化煤矸石地质聚合物抗压强度和微观结构的影响。利用XRD、FT-IR和SEM对活化煤矸石地质聚合物的微观结构进行了分析表征。结果表明,高温活化煤矸石有助于激发煤矸石中的活性组分,在煅烧温度为600 ℃时,高岭岩相完全消失,“鼓包峰”面积相对较大,可用于制备活化煤矸石地质聚合物。n(Na)/n(Al)的提高促进了地质聚合反应的进行,抗压强度也随之提高,同时随着激发剂模数的增加,抗压强度也随之增加。当n(Na)/n(Al)为0.62,激发剂模数为1.65时,试样7 d的抗压强度可达到52 MPa。活化煤矸石地质聚合物的聚合产物主要为水化硅铝酸钠(N-A-S-H)凝胶,水化产物致密,性能优良。

Preparation and Properties of Activated Coal Gangue Geopolymer

The original coal gangue was analyzed both qualitatively and quantitatively, the calcination temperature of activated coal gangue was optimized, and the effects of sodium-aluminum ratio (n(Na)/n(Al)=0.52, 0.57, 0.62) and the activator modulus (M=0.66, 0.69, 1.32, 1.65) on the compressive strength and microstructure of activated coal gangue geopolymer were investigated. The microstructure of activated coal gangue geopolymer was characterized by XRD, FT-IR and SEM. The results show that activated coal gangue at high temperature is helpful to activate the active components in coal gangue. When the calcination temperature is 600 ℃, the kaolinite facies disappears completely and “the bulge peak” area is relatively large, which can be used to prepare activated coal gangue geopolymer. The increase of n(Na)/n(Al) promots the geopolymer reaction, and the compressive strength is also increased. Meanwhile, the compressive strength is also increased with the increase of the excitation modulus. When n(Na)/n(Al) is 0.62 and the activator modulus is 1.65, the compressive strength of the sample on 7 d reaches to 52 MPa. The product of activated coal gangue geopolymer is sodium silicate hydrate (N-A-S-H) gel, the hydration product is compact and has good performance.