钙矾石结合氯离子能力的研究

Study on Chloride Binding Ability of Ettringite

采用化学合成法制备了钙矾石,通过平衡法研究了钙矾石结合氯离子的形式及能力,通过X射线衍射法和拉曼光谱分析法研究了钙矾石结合氯离子前后的晶体结构及官能团的变化以确定其结合氯离子的形式,通过滤取法验证了平衡法测试结果的可靠性。结果表明:钙矾石具有结合氯离子的能力,但其结合氯离子的形式是物理吸附,吸附等温线符合Freundlich关系曲线;经氯盐溶液侵蚀前后钙矾石晶体结构及官能团没有变化,进一步确定了钙矾石不具有化学结合氯离子的形式;与钠离子相比,侵蚀液中的钙离子能增强钙矾石吸附氯离子的能力。

The ettringite was prepared by chemical synthesis. The chloride binding form and ability of ettringite was detected by equilibrium method and the reliability of the results was verified by leaching method. Before and after ettringite exposed to chloride solution, the change of structure and functional groups of ettringite was investigated by X-ray diffraction and Raman spectrometry to reveal the chloride binding form. The results show that ettringite has sig- nificant chloride binding ability, and the chloride binding is because of physical adsorption. The chloride binding iso- therm of ettringite shows a good fit to Freundlich-type adsorption. The structure and functional groups of ettringite are not changed before and after ettringite exposed to chloride solution, which show that ettringite does not have the chemical binding with chloride. Compared with sodium ions, calcium ions can increase the chloride binding capacity of ettringite.