Production of alinite-chlormayenite clinker and its hydration behavior with increasing gypsum content

Abstract

An alternative low-energy alinite-chlormayenite clinker was produced and its hydration with different gypsum content was studied. The clinker was produced at 1225 °C using reagent-grade materials in an electric kiln with alinite, larnite, and chlormayenite content of 48, 24, and 16 wt%, respectively. The hydration kinetics of the clinker with different gypsum additions (0,10, 20, and 40 wt%) did not have a distinct induction period, and the hydration was faster than Portland cement. Alinite was in general more reactive than chlormayenite. In the presence of a limited amount of gypsum (10 and 20 wt%), alinite consumed gypsum to form ettringite within the first hour of hydration, and both alinite and chlormayenite formed Friedel's salt after gypsum was exhausted. Sufficient gypsum availability (40 wt%) slowed down the dissolution of alinite and chlormayenite for the first hour of hydration but enabled both chlormayenite and alinite to form ettringite.