机械活化对铁尾矿火山灰活性的影响

Effect of Mechanical Activation on Pozzolanic Activity of Iron Tailings

为了提高铁尾矿的火山灰活性,通过PSD,XRD,SEM等分析手段研究不同活化时间和球料比对铁尾矿砂浆活性指数的影响.实验结果表明:机械活化后的铁尾矿具有潜在的胶凝性能,其活性指数受活化时间及球料比(质量比)的影响较大,机械活化40 min,球料比(质量比)9∶4和机械活化30 min,球料比2∶1的铁尾矿活性指数可满足火山灰混合材料的使用要求.机械活化后铁尾矿的强度受胶凝性能影响大于微填充作用,活化后的铁尾矿颗粒微级配均匀程度均小于未活化的铁尾矿.铁尾矿的掺入改变了水泥体系的碱度及水化产物的孔结构并使更多的CO_(2)进入砂浆内部,导致生成了更多的碳酸盐类产物.

In order to improve the pozzolanic activity of iron tailings,the effects of different activation time and ball to material ratios on the activity index of iron tailing mortar were studied by means of PSD,XRD and SEM.The test results showed that the mechanically activated iron tailings have potential cementitious property,and its activity index is greatly affected by the activation time and ball to material ratio.The activity index of iron tailings with mechanical activation for 40 min,ball to material ratio of 9∶4 and mechanical activation for 30 min,and ball to material ratio of 2∶1 can meet the application requirements of pozzolanic mixtures.The cementitious property of mechanically activated iron tailings is greater than its micro-filling effect,and the micro-grading uniformity of activated iron tailings is less than that of non-activated iron tailings.The addition of iron tailings changes the alkalinity of cement systems and the pore structure of hydration products,and makes more CO_(2) enter the mortar,resulting in more carbonate products.