Effect of CaSO4 batching in raw material on the iron-bearing mineral transition of ferric-rich sulfoaluminate cement. (30th July 2020)

• Record Type: Journal Article
• Authors: Yao, Xingliang; Yang, Shizhao; Huang, Yongbo; Wu, Shuang; Yao, Yonggang; Wang, Wenlong
• Is Part Of: Construction & building materials. Volume 250(2020)
• Publication Date: 2020-07-30
• Subjects: Ferric-rich sulfoaluminate cement -- Phase composition -- Effective utilization rate -- CaSO4 -- C4A3-xFxS-; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118783
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A promising method to reduce the Al2 O3 content in FR-CSA cement was presented. The effect of CaSO4 on the phase composition of the FR-CSA clinker was shown. A method for calculating the incorporated level of Fe2 O3 in C4 A3-x Fx S was provided The effective utilizations of Al2 O3 and Fe2 O3 in FR-CSA clinker were improved. Abstract: Ferric-rich calcium sulfoaluminate (FR-CSA) cement is a type of low-carbon cement. Common CSA needs to consume a large number of bauxite during the preparation process. In FR-CSA, Fe2 O3 can act as an alternative for Al2 O3 by shaping some iron-bearing minerals (Ca4 Al2 Fe2 O10 (C4 AF), Ca2 Fe2 O5 (C2 F), and Ca4 Al6−2 x Fe2x SO16 ( C 4 A 3 - x F x S - )). In order to reduce the use of Al2 O3 and optimize the iron-bearing mineral compositions in the FR-CSA clinker, this study investigated the effect of CaSO4 batching in raw material on the formation of C4 AF and C 4 A 3 - x F x S - at 1250 °C. It was proved that CaSO4 plays an important role and the maximum incorporation amount of Fe2 O3 could be 16.18 wt% in C 4 A 3 - x F x S -, thereof x in the subscripts being 0.33. With the CaSO4 contents in the targeted clinker increasing from 0 to 10 wt%, the effective utilization rates of both Al2 O3 and Fe2 O3 significantly increased. When the excess amount of CaSO4 was >10 wt%, the effective utilization rate of Fe2 O3 increased but that of Al2 O3 decreased. The findings in this research can contribute to the mineral optimization of FR-CSA cement clinker and the improvement of effective utilization of Al2 O3 and Fe2 O3 . The production of high-performance FR-CSA cement becomes possible by the substitution of solid wastes containing relatively low Al2 O3 content for bauxite.