Hydration kinetics of calcium sulphate hemihydrate: A comparison of models

Abstract

Abstract The kinetic equations derived by Schiller, Ridge, Taplin and, Combe, Smith and Braden, for the hydration of calcium sulphate hemihydrate, based on crystallisation theory, are compared in order to establish which model describes the reaction best. Schiller's, Ridge's and Combe's models show considerable departures from the data, whereas Taplin's model fits the data extremely well. A simple Product model also fits well if the rate is assumed to be temperature dependent.