Hydration of Calcium Sulphate Hemihydrate: Review and Analysis of Reaction Description Models

A review and critical analysis of kinetic models describing the CaSO4 · 0.5H2O hydration process is presented. Special attention is paid to their application to describe experimental data obtained by the conductometric method. Based on the analysis, it was found that stochastic models taking into account the probabilistic aspects of hydration demonstrate the highest compliance degree to the experiment. This allows to draw a reasonable conclusion on the advantages of the stochastic approach in describing complex physico-chemical processes characterized by a significant uncertainty degree. The analysis of the existing kinetic models of calcium sulfate hemihydrate hydration revealed their limitations in relation to real conditions. Traditional deterministic models based on chemical kinetic equations are not able to adequately consider random fluctuations occurring at the microscopic and molecular structural levels. This paper shows that stochastic models have significant advantages in describing complex processes such as CaSO4 · 0.5H2O hydration.