Belite-calcium sulfoaluminate cement prepared with phosphogypsum: Influence of P2O5 and F on the clinker formation and cement performances. (10th April 2019)

• Record Type: Journal Article
• Authors: Huang, Yongbo; Qian, Jueshi; Kang, Xiaojuan; Yu, Jincheng; Fan, Yingru; Dang, Yudong; Zhang, Wensheng; Wang, Shoude
• Is Part Of: Construction & building materials. Volume 203(2019)
• Page Start: 432
• Page End: 442
• Publication Date: 2019-04-10
• Subjects: Phosphogypsum -- P2O5 and F impurities -- Belite-calcium sulfoaluminate cement; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.01.112
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: P2 O5 and F impurities in PG could promote the formation of BCSA clinker. BCSA clinker prepared with PG could be obtained at 1200 °C. Slight negative influence of P2 O5 and F on BCSA cement performances can be negligible. When PG is used as the added gypsum, the P2 O5 negatively affects the BCSA cement performances. Abstract: The phosphogypsum (PG) was used for the preparation of belite-calcium sulfoaluminate (BCSA) clinker and as the added gypsum of BCSA cement. The influences of P2 O5 and F impurities in PG on clinker formation and cement hydration were investigated. Results demonstrate that the P2 O5 and F impurities in PG could promote the formation of clinker at 1100 °C. The clinker prepared with PG could be obtained at 1200 °C which is ∼50 °C lower than the clinker prepared with natural gypsum (NG). Both P2 O5 and F could be immobilized in C4 A3 S ¯ and stabilized cubic C4 A3 S ¯ at the expense of orthorhombic C4 A3 S ¯ . The hydration reactivity of C4 A3 S ¯ in the BCSA cement lowered down. However, the impurities merely slightly affected the 6 h, 12 h and 1 d compressive strength development, which could be negligible. When the original PG was used as the added gypsum of BCSA cement, the soluble phosphorus impurity pronged the setting time of the cement. Besides, the soluble phosphorus impurity could also inhibit the hydration of C4 A3 S ¯ and lower down the compressive strength of BCSA cement. The results will lay foundation for the utilization of PG in BCSA cement production.