Crystallization behavior of calcium silicate hydrate in highly alkaline system: Structure and kinetics

作者：Qi, Fang; Cao, Junya; Zhu, Ganyu^*; Sun, Jian; Li, Shaopeng; Wu, Wenfen; Zheng, Jun; Li, Huiquan; Zhang, Yimin^*

来源：Journal of Crystal Growth, 2022, 584: 126578.

DOI：10.1016/j.jcrysgro.2022.126578

• A1
• Highly alkaline solution
• Causticization
• Crystal structure
• Crystal morphology
• Kinetics
• B1
• Calcium silicate hydrate

During utilization of high silicon solid wastes, a characteristic and complex desilication solution (DSS) generated, remains an important subject to be as precursor of calcium silicate hydrate (C-S-H) crystallization. By using the mixed suspension mixed product removal (MSMPR) crystallizer, the crystallization behavior of C-S-H in DSS was investigated. The effects of temperature, initial Ca/Si ratio, silicate concentrations, solvent alkalinity on the morphology and structure of synthesized C-S-H were investigated through X-ray diffraction, scanning electron microscopy, laser particle size analyzer, and 29Si magic angle spinning nuclear magnetic resonance. The crystallization growth rate and particle size of C-S-H were positively correlated with temperature. The elevation of Ca/Si molar ratio will lead to shortening of the silicate chain to form more monomers. The increase of silicate concentration and solvent alkalinity will result in the formation of shorter silicate chains. This work provides theoretical guidance for precise preparation and design of C-S-H synthesized by a causticization strategy.

• 单位
  test; 中国科学院研究生院; TEST