Effect of CaO content in raw material on the mineral composition of ferric-rich sulfoaluminate clinker. (10th December 2020)

• Record Type: Journal Article
• Authors: Yao, Xingliang; Yang, Shizhao; Dong, Hua; Wu, Shuang; Liang, Xuhui; Wang, Wenlong
• Is Part Of: Construction & building materials. Volume 263(2021)
• Publication Date: 2020-12-10
• Subjects: Ferric-rich sulfoaluminate cement -- CaO -- Phase composition -- Iron-bearing phase; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.120431
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: CaO content in raw materials influences the phase composition of the FR-CSA clinker. Lower CaO content in raw mixture promotes the incorporation of Fe2 O3 into ye'elimite. A method to optimize the phase composition of FR-CSA clinker is provided. Abstract: Ferric-rich calcium sulfoaluminate (FR-CSA) cement is an eco-friendly cement. Fe2 O3 exists in different minerals of FR-CSA clinker, e.g., Ca4 Al2 Fe2 O10 (C4 AF), Ca2 Fe2 O5 (C2 F), and Ca4 Al6-2 x Fe2 x SO16 (C4 A3- x F x S - ). The mineral composition depends on the chemical composition of the raw materials and significantly determines the reactivity of FR-CSA cement. To optimize the phase composition of the FR-CSA clinker, chemical reagent raw mixtures with different amounts of CaO were used to prepare the FR-CSA clinker. X-ray diffraction (XRD) analysis, Rietveld quantitative phase analysis (RQPA), Fourier Transform Infrared spectroscopy (FT-IR), and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) were used to identify the mineralogical conditions of the FR-CSA clinker. The results indicated that the amounts of CaO in raw materials greatly affected the iron-bearing phase formation in the FR-CSA clinker. With decreasing CaO content involved in calcination reaction, the amounts of Fe2 O3 incorporated in C4 A3- x F x S - increased up to 17.72 wt% (where x = 0.36). The findings make it possible to optimize the mineral composition of the FR-CSA clinker by changing the CaO content in raw materials. Furthermore, low CaO content in the raw material is beneficial to the formation of C4 A3- x F x S -, which enables the use of solid wastes containing low calcium for producing FR-CSA cement.