Submicron metakaolin (SMK) is an ultrafine aluminosilicate material, which was used for improving properties of cement slurry in this paper. SMK was added to the slurry mix as a partial substitute for Portland cement in proportions of 1%, 3%, 5% and 7%. To explore the influence of SMK on hydration of cement slurry, the heat flow and pH measurement was used to indicate that SMK significantly increased the rate of heat release and total heat release, increase the rate of calcium hydroxide (CH) generation in the pore solution at initial stage of hydration. The hardened specimens at different ages (3–28 days) were measured by X-ray diffraction, Differential Thermal Analysis and Compressive strength. The results showed that: SMK displayed pozzolanic effect which reduced CH content and increased the generation of Calcium Silicate Hydrate (C-S-H) gel at later stages of hydration. The compressive strength tests showed that SMK highest increased compressive strength of the slurry by 67% and 19% at 3d and 28d over plain cement slurry. It was concluded that SMK could improve many properties of cement slurry and has the use potential on actual projects.

亚微米偏高岭土（SMK）是一种超细的铝硅酸盐材料，被用于改善水泥浆的性能。将SMK以1％，3％，5％和7％的比例添加到水泥浆中，作为波特兰水泥的部分替代品。为了探讨SMK对水泥浆水化的影响，通过热流和pH测量表明SMK显着提高了热释放速率和总热释放速率，增加了孔隙溶液中氢氧化钙（CH）的生成速率在水合作用初期。通过X射线衍射，差热分析和抗压强度测量了不同年龄（3–28天）的硬化样品。结果表明：SMK表现出火山灰作用，可降低CH含量并增加水合后期硅酸钙水合物（CSH）凝胶的生成。抗压强度测试表明，SMK在3d和28d时比普通水泥浆具有最高67％和19％的抗压强度。结论是，SMK可以改善水泥浆的许多性能，并在实际项目中具有使用潜力。