The fundamentals of the mineralogy and reactivity of the clinker containing high sulfur content

Industrial byproducts and waste materials are commonly used as either alternate fuels or substitute raw materials in the cement manufacturing process. In general, the four primary mineral compounds (3CaO•SiO2 (C3S) or alite, 2CaO•SiO2 (C2S) or belite, 3CaO•Al2O3 (C3A) or aluminate, and 4CaO•Al2O3•Fe2O3 (C4AF) or ferrite) in the cement are well controlled and preserved even with the use of byproduct and waste materials. However, the use of these materials may significantly change the minor components in the clinker and cement. This change can potentially affect the clinkering process and cement performance.
When using industrial byproducts and waste materials, the most frequently encountered minor component change in the clinker is associated with the sulfur content increase. This research showed that increased sulfur content in the clinker significantly promotes the formation and growth of the alite phase; silicate mineral compounds are better distributed within the clinker matrix; belite clusters are significantly reduced; and the reactivity of the cement made with high sulfur clinker is increased.

Author: H. Wang, C. Qi, H. Farzam, E. Caballero

Section: Science and production

Keywords: clinker chemistry, sulfur, alite, belite, crystals, mineral, phase reactivity