Stability of Tricalcium Silicate and Other Primary Phases in Portland Cement Clinker

详细信息    查看全文

• 作者：Xuerun Li ; Xiaodong Shen ; Mingliang Tang ; Xiaodong Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：February 5, 2014
• 年：2014
• 卷：53
• 期：5
• 页码：1954-1964
• 全文大小：834K
• ISSN：1520-5045

文摘

The decomposition of alite (C₃S) in Portland cement clinker was investigated by isothermal annealing, aiming to provide more fundamentals for the cooling process of cement clinker so as to search for potential chance for modification of the ongoing cooling process. Clinker phases were analyzed with quantitative X-ray diffraction technique. Scanning electron microscope and microscopy were used to investigate the microstructure. The fastest decomposition rate appeared at 1125鈥?150 掳C in a temperature鈥搕ime鈥搕ransformation diagram. The decomposition of alite primarily occurred at the cracks, edges, and defects of the clinker. The resultant f-CaO segregated, which mainly controlled the decomposition rate of alite. The three-dimensional diffusion model (Jander) was suitable for the decomposition kinetics of alite with a non-Arrhenius behavior for the activation energy which was a piecewise linear function with temperature. Interstitial phases recrystallized during the annealing process, accompanied by an increase of the C₃A and C₄AF contents. The recrystallization of C₃A was temperature-dependent, especially above 1000 掳C.