Dicalcium silicate doped with sulfur

Abstract

Dicalcium silicate (Ca2SiO4 or C2S) containing foreign ions occurs as a component of Portland cement clinker and is called belite. Belite has a lower hydraulic activity than alite, which is the main component of Portland cement clinker. Belite can be prepared at lower expenditure and its hydraulic activation can have important impact on the economy and sustainability of the cement industry. This research focused on the activation of C2S by incorporation of SO3 into its crystal structure. This paper describes experiments with pure chemicals that characterise substitution of SiO2 by SO3 and its influence on the hydraulic activation of C2S. It was confirmed that sulfur stabilises the monoclinic modification β-C2S. The maximum content of SO3 in C2S under common laboratory burning conditions was approximately 4·4 wt%. The hydraulic activity of prepared β-C2S doped with SO3 was up to three times higher than in the reference non-activated β-C2S.