广西平果拜耳法赤泥的水硬胶凝特性

摘要

借助XRD、FTIR、TG－DSC和SEM测试表征了广西平果拜耳法赤泥在电石渣和脱硫石膏复合激发作用下的水化产物及硬化浆体的微观结构，研究了该赤泥在复合激发下的水硬胶凝特性。结果表明：该赤泥在电石渣和脱硫石膏的复合激发下水化3、7、28 d的抗压强度均大于4 MPa，表现出一定的水硬胶凝特性；该体系水化反应生成了钙矾石、C－S－H凝胶、富钠钙柱石、无水芒硝和氢氧化铝等。钙矾石晶体相互搭接形成骨架结构，成为胶凝材料硬化浆体强度的主要来源，C－S－H凝胶等胶结或充填在钙矾石中间，加固并致密了凝结硬化体的结构。以上研究成果可为拜耳法赤泥用于地下采矿胶结充填胶凝材料提供理论参考。%In order to understand the cementitious characteristics of Bayer process red mud from Guangxi Pingguo alumi-num corporation,XRD,FTIR,TG-DSC and SEM techniques were used to investigate the hydration products and microstructure of the hardened pastes,which formed after a hydration process of the red mud compound-activated by carbide slag and flue gas desulfurization gypsum.The results indicated that the red mud could show hydraulic cementitious properties after compound-ac-tivated by carbide slag and flue gas desulfurization gypsum,and its compressive strength was all higher than 4 MPa at the cu-ring age of 3,7 and 28 d.Ettringite,C-S-H gel,Na-rich meionite,thenardite and aluminum hydroxide were generated in the process of this hydration reaction system.Ettringite crystal overlapped each other to form the skeleton structure,which ensured the strength of cementing materials.C-S-H gel and etc,cemented or filled in the middle of the skeleton structure of ettringite, which reinforced and compacted the structure of the hardened paste.The research results can praide theory reference for appli-cation of Bayer Process red mold in underground mining cementitias filling material.