INFLUENCE OF ALKALIS ON THE PHASE DEVELOPMENT OF BELITE-SULFOALUMINATE CLINKERS
This paper presents a study on the influence of different amounts of alkalis (K₂O and Na₂O) on clinker phase formation, microstructure, phase composition and reactivity of belite-sulfoaluminate cement clinker. Using X-ray powder diffraction and scanning electron microscopy with energy dispersive spe...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
University of Chemistry and Technology, Prague
2022-11-01
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Series: | Ceramics-Silikáty |
Subjects: | |
Online Access: |
http://www.ceramics-silikaty.cz/index.php?page=cs_detail_doi&id=1600
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Summary: | This paper presents a study on the influence of different amounts of alkalis (K₂O and Na₂O) on clinker phase formation, microstructure, phase composition and reactivity of belite-sulfoaluminate cement clinker. Using X-ray powder diffraction and scanning electron microscopy with energy dispersive spectrometry, it was found that the amount of C₂S and C₄AF increases with the incorporation of alkalis, while the amount of C₄A₃S and CS decreases. In addition to the major phases, the samples with alkalis also consist of minor phases such as C₃A (tricalcium aluminate), KS (arcanite), and KC₂S₃ (Ca-langbeinite). The major ions in the major phases were substituted by alkali cations and some other ions (Ca2+, Al3+, Fe3+, S2-, S6+, Si4+). The alkalis also affect the microstructure of the clinker, e.g., the shape of the grains. Consequently, isothermal calorimetry was used to detect differences in hydration kinetics. The clinker with 2 wt. % K₂O content was the most reactive, while the sample with 0.5 wt. % Na content was the least reactive. The latter was primarily influenced by the content of the main and minor phases of the clinker. |
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ISSN: | 0862-5468 1804-5847 |