以热活化氧化铝赤泥为主要原料制备赤泥地聚物砂浆,对比研究了激发剂种类和掺量对赤泥地聚物力学性能的影响及其合成机理。结果表明,水玻璃、石灰-碱（质量比为2∶1）、石膏-碱（质量比为2∶1）均能改善氧化铝赤泥的反应活性,促进赤泥地聚物的合成,其中水玻璃（氧化硅与氧化钠物质的量比为1.5）的改性效果最为显著。水玻璃、石灰-碱、石膏-碱的最佳掺量分别为20%、7%、10%。水玻璃掺量为20%时,赤泥地聚物砂浆28 d抗压强度和28 d抗折强度分别为32.1 MPa和6.0 MPa。改变激发剂的种类和掺量,可以调整赤泥地聚物砂浆体系的碱度,改变铝硅酸结构的解聚和地聚物的缩聚过程,从而影响其力学性能。

Red mud geopolymer mortars were prepared with thermally activated alumina red mud as main raw material.The effects of the kinds and dosages of chemical activators on the mechanical properties and red mud geopolymer synthesis mechanism were dis cussed.The results showed that sodium silicate,gypsum-alkali with mass ratio of 2∶1 and lime-alkali with mass ratio of 2∶1,can improve the reactivity of alumina red mud and promote the synthesis of red mud geopolymer.Among them,sodium silicate（the amount-of-substance ratio of silicon oxide to sodium oxide is 1.5） had the most remarkable modification effect.The optimum dosage of sodium silicate,gypsum-alkali and lime-alkali was 20%,7% and 10%,respectively.When the dosage of sodium silicate was 20% compressive and flexural strength of red mud geopolymer mortar at 28 d were 32.1 MPa and 6.0 MPa,respectively.The kinds and dosages of activator changed the alkalinity of red mud geopolymer mortar system,adjusted the depolymerization of aluminosilicate and the condensation process of geopolymer,and thus,affected its mechanical properties.