高硅型铁尾矿机械活化效果及机理研究

Mechanical Activation of High Silicon Iron Tailings and Its Mechanism

为促进铁尾矿工程应用,以辽宁本溪高硅型铁尾矿为例,研究机械活化方式和活化时间对铁尾矿形貌及活性的影响。通过粒度分析、胶砂试验和石灰吸附测试等,探究机械活化对铁尾矿粒径分布、比表面积、活性指数和火山灰活性的影响;通过X射线衍射和扫描电镜分析,探究胶凝体系的水化反应机理。结果表明:机械活化可以优化铁尾矿粒径,提高颗粒圆度,降低颗粒表面结晶度,且粉磨40~60 min效果最佳;湿磨活化50 min时,活性指数达96.6%,火山灰活性大幅提升,湿磨活化效果显著优于干磨;机械活化促进了铁尾矿与水泥的二次水化反应,提升了胶凝体系性能。

In order to promote engineering application of iron tailings,taking Benxi high silicon iron tailings in Liaoning Province as an example,the effects of different mechanical activation methods and time on the activity and morphology of iron tailings were studied.The effect of mechanical activation on the particle size distribution,specific surface area,activity index and pozzolanic activity of iron tailings were detected by grading analysis,mortar test,lime adsorption test and so on.The hydration reaction mechanism of cementitious system was explored by X-ray diffraction and scanning electron microscopy analysis.The results show that mechanical activation can refine the partical size of iron tailings,increase the particle roundness and reduce surface crystallinity.Grinding for 40~60 min has the best effect.The activity index is up to 96.6%after wet grinding for 50 min,and the pozzolanic activity is significantly enhanced.The activation effect of wet grinding is better than that of dry grinding.Mechanical activation promotes the secondary hydration reaction between iron tailings and cement,and improves the performance of cementitious system.