正交实验优化钨尾矿地聚物的蒸压养护制度

以钨尾矿为主要硅铝原料、偏高岭土为铝校正料制备地聚物,以恒压压力、恒压时间和卸压时间作为影响因素,以地聚物试块的7d龄期抗压强度作为考察指标,通过正交实验获取最佳蒸压养护条件,并借助XRD和SEM对试块的微结构进行表征。结果表明:恒压压力对钨尾矿地聚物抗压强度影响最大;在恒压压力为0.8 MPa、恒压时间为60 min、卸压时间为40 min时,地聚物可达到最高抗压强度31.13 MPa;微观结构分析说明适宜的蒸压养护制度可使原料中低活性硅铝成分的溶出得到强化,进而提高地聚物的胶凝性并改善其微观结构。

Optimizing autoclaved curing regime for tungsten tailing-based geopolymer by orthogonal experiment

Combined with metakaolin as Al-correcting material, tungsten tailing was used as the main raw Si-Al material for geopolymer synthesis. In order to obtain the best autoclaved curing regime, orthogonal tests were conducted on condition that curing pressure, curing time and pressure relief time were acted as the affecting factors, and 7-day compressive strength of geopolymer was employed as index of evaluation. Besides, microstructure of the typical geopolymer samples were characterized by SEM and XRD. Results show that, curing pressure had thegreatest influence on compressive strength of geopolymer; Geopolymer can reach the highest compressive strengthof 31.13 MPa when curing pressure was 0.8 MPa, curing time was 60 min and pressure relief time was 40 min; Microstructure analyses indicated that, appropriate autoclaved curing regime can enhance dissolution of low-reactive Si-Al components from raw materials, then increase cementitious property and improve microstructure of geopolymer.