Hydration of calcium sulphate hemihydrate. I. Kinetics of the reaction

The hydration of finely divided calcium sulphate hemihydrate in concentrated aqueous suspensions was studied under isothermal and adiabatic conditions. The reactions in both cases were strongly self‐accelerating and followed similar courses either when accelerated or unmodified. The kinetics approximated to those of an ideal system proposed previously to explain the kinetics of setting of calcined gypsum. With the inhibited reaction, agreement with the behaviour of the ideal system was not so close. The relationship between the kinetics of the isothermal and adiabatic hydrations is discussed.