激发剂对赤泥-黄金尾矿-碱矿渣体系性能的影响

为提高危险固体废弃物的综合利用水平，依据赤泥、黄金尾矿及矿渣三种固体废弃物的特性，研究NaOH、KOH和Na₂SiO₃三种激发剂对赤泥-黄金尾矿碱矿渣体系性能的影响。并在此基础上通过XRD、FT-IR、TGA/DSC和SEM等表征手段明晰其微观反应机理。结果表明，当Na₂SiO₃为激发剂时，复合胶凝材料体系的激发效果最好，标养3天的胶砂抗折强度和抗压强度分别达到5.5和23.5 MPa;标养28天的胶砂试件抗折强度和抗压强度分别为8.8和43.21 MPa,可达到P·I42.5水泥强度指标。通过微观分析得知，试件的主要强度来源物质为钙矾石和水化硅铝酸钙凝胶，力学性能高的材料其微观结构更为密实，碱激发水化产物数量更多。

Influence of Activator on Properties of Red Mud-Gold Tailings-Alkali Slag System

In order to improve the combined utilization of hazardous solid waste, red mud-gold tailings-slag based alkali-activated cementitious materials were prepared with red mud, gold tailings and slag from Bayer process as active materials and NaOH, KOH and Na2SiO3 as activators respectively. Its mechanical properties were tested, and microscopic mechanism was characterized by XRD, FT-IR, TGA/DSC and SEM. The experimental results show that different kinds of activators had great influence on mechanical properties of the system. When Na2SiO3 is used as activator, the excitation effect of the system is the best, and the flexural strength and compressive strength of the standard mortar specimen at 3 days are 5.5 MPa and 23.5 MPa respectively. The flexural strength and compressive strength of 28 d standard mortar specimens are 8.8 MPa and 43.21MPa respectively, which can reach the cement strength index of P?I42.5. Through microscopic analysis, it is known that main strength sources of specimens are ettringite and hydrated calcium aluminosilicate gel, and the materials with high mechanical properties have more dense microstructure and more alkali-stimulated hydration products.