SCI和EI收录∣中国化工学会会刊

›› 2017, Vol. 25 ›› Issue (10): 1539-1544.DOI: 10.1016/j.cjche.2017.02.012

• Materials and Product Engineering • 上一篇    下一篇

Crystallization of calcium silicate at elevated temperatures in highly alkaline system of Na2O-CaO-SiO2-H2O

Ganyu Zhu1, Huiquan Li1,2, Shaopeng Li1, Xinjuan Hou1,2, Xingrui Wang1   

  1. 1 Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • 收稿日期:2016-10-27 修回日期:2017-02-14 出版日期:2017-10-28 发布日期:2017-03-21
  • 通讯作者: Huiquan,E-mail address:hqli@ipe.ac.cn
  • 基金资助:
    Supported by the National Natural Science Foundation of China (51304184) and the Coal Based Key Scientific and Technological Project of Shanxi Province (MC2014-06).

Crystallization of calcium silicate at elevated temperatures in highly alkaline system of Na2O-CaO-SiO2-H2O

Ganyu Zhu1, Huiquan Li1,2, Shaopeng Li1, Xinjuan Hou1,2, Xingrui Wang1   

  1. 1 Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-10-27 Revised:2017-02-14 Online:2017-10-28 Published:2017-03-21
  • Supported by:
    Supported by the National Natural Science Foundation of China (51304184) and the Coal Based Key Scientific and Technological Project of Shanxi Province (MC2014-06).

摘要: In Na2O-CaO-SiO2-H2O system, systematic investigations of phase and morphology of calcium silicate in hydrothermal conditions were concisely conducted for high-value utilization of silicon resource in high-alumina fly ash (HAFA). The results show that crystal composition and phase may be affected by relatively low concentration of NaOH, and sodium ions are rearranged into the structure to form NaCaHSiO4 and Na2Ca3H8Si2O12 with different C/S ratio at high concentration of NaOH. In addition, phases in wollastonite group possess the morphology of nanofiber. Formation of nanofiber is attributed to the difference of surface energies between axial and radial direction, and higher temperatures lead to easier growth along radial direction. The preparation of C-S-H with different phases and morphologies can guide for the application of silicate solution with high alkalinity with different purposes.

关键词: Crystallization, Hydrothermal, Calcium silicate, Nanofiber

Abstract: In Na2O-CaO-SiO2-H2O system, systematic investigations of phase and morphology of calcium silicate in hydrothermal conditions were concisely conducted for high-value utilization of silicon resource in high-alumina fly ash (HAFA). The results show that crystal composition and phase may be affected by relatively low concentration of NaOH, and sodium ions are rearranged into the structure to form NaCaHSiO4 and Na2Ca3H8Si2O12 with different C/S ratio at high concentration of NaOH. In addition, phases in wollastonite group possess the morphology of nanofiber. Formation of nanofiber is attributed to the difference of surface energies between axial and radial direction, and higher temperatures lead to easier growth along radial direction. The preparation of C-S-H with different phases and morphologies can guide for the application of silicate solution with high alkalinity with different purposes.

Key words: Crystallization, Hydrothermal, Calcium silicate, Nanofiber