| 摘要: |
| 采用Struble法合成碳硫硅钙石，研究了CaCl2，CaO以及Na2SO4，Na2CO3对碳硫硅钙石形成的影响，并用红外光谱（FTIR）和X射线衍射（XRD）分析了不同龄期的生成产物.结果表明：CaCl2和CaO均能提高碳硫硅钙石形成的速率，且CaCl2的加速效果更明显；碳硫硅钙石的形成速率随Ca2+含量的增加而增大，提高Na2SO4和Na2CO3的含量并不能显著加速碳硫硅钙石的形成；硅酸盐中的硅氧四面体向碳硫硅钙石中的硅氧八面体的转变是碳硫硅钙石形成反应的速率控制步骤，Ca2+可提高碳硫硅钙石形成过程中硅氧八面体过渡态的稳定性并促进其形成，从而提高了碳硫硅钙石的生成速率.因此，可通过降低Ca2+含量来减缓碳硫硅钙石的生成. |
| 关键词: 碳硫硅钙石 钙离子 硅氧八面体 机理 |
| DOI：103969/jissn1007 9629201503003 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51278497，51178363） |
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| Acceleration Effect of Calcium Ion on Formation of Thaumasite |
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XIAO Jia1, MENG Qingye1, MA Baoguo2, WANG Yingbin2
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1.School of Civil Engineering, Central South University, Changsha 410075, China;2.State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
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| Abstract: |
| Effects of calcium chloride, calcium oxide, sulfate sodium and carbonate sodium on thaumasite formation were investigated by synthesizing thaumasite through Struble method. Precipitates at different ages of thaumasite formation reaction were characterized by FTIR and XRD. It is indicated that both calcium chloride and calcium oxide can increase the rate of thaumasite formation, and calcium chloride plays a more significant role in accelerating formation of thaumasite than calcium oxide does. The rate of thaumasite formation increases as the amount of calcium ion increases, while increasing the amount of sulfate sodium and carbonate sodium failed to enhance obviously thaumasite formation. The transition from silicon oxygen tetrahedron of silicate to silicon oxygen octahedron of thaumasite is rate determining step of thaumasite formation. Moreover, calcium ion can improve stability of silicon oxygen octahedron, transition state of thaumasite formation, which results in increasing the rate of thaumasite formation. Therefore, thaumasite formation can be retarded by lowering the amount of calcium ion. |
| Key words: thaumasite calcium ion silicon oxygen octahedron mechanism |
