【摘要】 将煤系高岭土矿样进行焙烧活化,得到高火山灰活性的偏高岭土,对偏高岭土物相变化进行分析,考察偏高岭土抗硫酸镁侵蚀性能,并通过X射线衍射（XRD）、场发射扫描电子显微镜-能谱仪（FESEM-EDS）研究了抗硫酸镁侵蚀机制。结果表明,煤系高岭土经800℃焙烧活化可完全脱除其结构中的羟基,制得最高活性的偏高岭土。偏高岭土掺和至水泥砂浆中,会显著降低其受MgSO₄侵蚀时的膨胀率和强度损失,偏高岭土会增加水化硅酸钙（C-S-H）凝胶的Al含量,降低内层钙硅比和Mg、S含量,使得C-S-H凝胶更为密实稳定,侵蚀产物石膏与单硫型水化硫铝酸钙（AFm）含量显著降低,表现出优良的抗硫酸镁侵蚀性能。更多还原

【Abstract】 This paper firstly activated coal-series kaolin by roasting to prepare metakaolin with high pozzolanic activity and its phase transformation was researched, then the erosion resistance to MgSO₄ was studied and its mechanism was analyzed by XRD and FESEM-EDS. The results showed that the optimal activation temperature was 800 ℃ accompanied with complete dehydroxylation and the highest active metakaolin was obtained. The blending of metakaolin into cement mortar would reduce the expansion and strength loss under MgSO₄ erosion. The XRD and FESEMEDS analyses showed that metakaolin would increase Al content and decrease ratio of Ca to Si and Mg, S contents of inner layer, which resulted in the denser and stable C-S-H gels and remarkable reduction of erosion products（gypsum and AFm）, showing the excellent erosion resistance to MgSO₄.更多还原