Thermodynamic Analysis of the Processes of Dehydration of Clay Minerals and Synthesis of Clinker Minerals in the Presence of a Coal–Alkaline Additive

Abstract

A theoretical justification for the influence of a coal–alkaline additive which not only changes the surface properties of the disperse particles, but also intensifies the processes of hydration of clay minerals and the formation of dicalcium silicate and calcium aluminate, is given. A thermodynamic analysis of the interaction between the products of clay decomposition and calcium oxide in presence or absence of the additive is performed. The thermodynamic calculations of the probability of the formation of the products of decomposition of clay and clinker minerals at the temperatures up to 1400 K are presented. The introduction of the coal–alkaline reagent into the carbonate/clay mixture allows significantly decreasing the temperature of clay-minerals dehydration; the processes of interaction of the substances in a solid phase followed by the formation of dicalcium silicate and calcium aluminate can occur at temperatures which are 20–102°C lower than the ones carried out in the absence of the additive. Using thermodynamic calculations makes it possible to theoretically prove the efficiency of using such an additive.