Kang Dong, Yang Zhijie, Zhang De, Jiao Yang, Fang Chenyang, Wang Kaiyue
School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China.
Key Laboratory for Green Development of Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China.
Materials (Basel). 2023 Mar 7;16(6):2154. doi: 10.3390/ma16062154.
In this study, microporous calcium silicate was synthesized from a silicon solution of fly ash extracted by soaking in strong alkali as a silicon source. By means of XRD, TEM, FTIR, and thermodynamic calculations, the crystal evolution and growth process of microporous calcium silicate were studied under the synthesis temperature of 295~365 K. The results show that calcium silicate is a single-chain structure of the Si-O tetrahedron: Q1 type Si-O tetrahedron is located at both ends of the chain, and the middle is the [SiO] tetrahedron connected by [O] coplanar, and Ca is embedded in the interlayer structure of calcium silicate. The formation rate and crystallization degree of calcium silicate hydrate were positively correlated with temperature. When the synthesis temperature was 295 K, its particle size was about 8 μm, and when the synthesis temperature was 330 K, a large number of amorphous microporous calcium silicate with a particle size of about 14 μm will be generated. When the temperature was above 350 K, the average particle size was about 17 μm. The microporous calcium silicate showed obvious crystalline characteristics, which indicate that the crystallization degree and particle size of microporous calcium silicate could be controlled by a reasonable synthesis temperature adjustment.
在本研究中，以通过强碱浸泡提取的粉煤灰硅溶液为硅源合成了微孔硅酸钙。借助XRD、TEM、FTIR和热力学计算，研究了在295~365 K合成温度下微孔硅酸钙的晶体演化和生长过程。结果表明，硅酸钙为Si-O四面体的单链结构：Q1型Si-O四面体位于链的两端，中间是由[O]共面连接的[SiO]四面体，Ca嵌入硅酸钙的层间结构中。水合硅酸钙的形成速率和结晶度与温度呈正相关。合成温度为295 K时，其粒径约为8μm；合成温度为330 K时，会生成大量粒径约为14μm的无定形微孔硅酸钙。温度高于350 K时，平均粒径约为17μm。微孔硅酸钙呈现出明显的结晶特征，这表明通过合理调整合成温度可以控制微孔硅酸钙的结晶度和粒径。
