碱热激发石英胶凝材料的抗压强度及胶凝机理

Compressive Strength of Alkali-thermal Activated Quartz Based Cementing Materials and the Cementing Mechanism

加碱煅烧后,石英粉在石灰激发下具有一定的水硬胶凝性。以水泥净浆抗压强度为依据初步优化了制备工艺,结果表明,当烧碱添加量为7.5%,煅烧温度为900℃时,掺入40%石灰得到的水泥净浆28 d抗压强度达到17.6 MPa。综合X射线衍射、热分析、红外分析、扫描电镜与能谱分析表明:石英在煅烧时生成了非晶态的硅酸钠,后者与石灰反应生成非晶态的水化硅酸钙(钠)胶凝。这种胶凝材料具有煅烧温度低、废气和直接碳排放少等优点,可为开发新的胶凝材料和处理高硅固体废物提供新思路。

After calcined with NaOH, quartz showed reasonable hydraulic cementing properties when mixing with Ca（OH）v The synthesis technology parameters were primitively optimized according to the compressive strengths of the net cement pastes. It shows that calcination temperature 900 ℃ and Ca（OH）2 content 40% lead to the highest 28 d strength 17.6 MPa. It is proposed through XRD, DSC/TGA, FTIR, SEM and EDS analyses that amorphous sodium silicates are produced during calcination and they react with Ca（OH）2 to generate hydrous silicates that harden the pastes during hydration. With advantage of lower calcination temperature and less waste gases and direct carbon emissions, this cement provides new thought for dealing with solid waste materials consisting of high content of silica and developing new type of cement.