锑尾矿粉基复合胶凝材料的制备及水化特性

Preparation and Hydration Characteristics of Antimony Tailings Powder-Based Composite Cementitious Material

以锑尾矿微粉作为主要原料,辅以水泥熟料、活化剂和促凝剂制备锑尾矿粉基复合胶凝材料,并从力学性能及微观结构等方面对复合胶凝材料的水化特性进行探究。结果表明,试件浆体的抗压强度随着锑尾矿微粉掺量的增加而减小,质量掺量为70%时仍满足尾矿固化筑坝要求。不同活化剂对复合胶凝材料强度的影响显著不同,当掺入磷石膏和生石灰且其质量比例为2∶1时,试件活化效果最好,7 d抗压强度达到10.42 MPa。试件浆体的最终水化产物主要为C-S-H凝胶和氢氧化钙,此外还有少量钙矾石生成。选择铝酸盐水泥作为促凝剂且质量掺量为3%时,能有效缩短试件凝结时间,满足快速固化的要求。同时利用锑尾矿粉基复合胶凝材料可以实现细粒锑尾矿的快速原位固化。

Antimony tailings fine powder was used as the main raw material,supplemented with cement clinker,activator and accelerator to prepare antimony tailings powder-based composite cementitious material.Hydration characteristics of composite cementitious materials in terms of mechanical properties and microstructure were investigated.The results show that compressive strength of specimen slurry decreases with the increase of the amount of antimony tailings fine powder.When the mass fraction of admixture is 70%,it still meets the requirements of tailings solidification and damming.Effects of different activators on the strength of composite cementitious materials are significantly different.When phosphogypsum and quicklime are mixed and the mass ratio is 2∶1,the activition effect of specimen is the best,and compressive strength reaches 10.42 MPa in 7 d.The final hydration products of specimen slurry are mainly C-S-H gel,calcium hydroxide,and a small amount of ettringite.When aluminate cement is selected as the accelerator and the mass fraction is 3%,it effectively shortens the setting time of specimen and meets the requirements of rapid solidification.The use of antimony tailings powder-based composite cementitious material achieves rapid in-situ solidification of fine-grain antimony tailings.