Thermodynamic data of the calcium sulphate solution process between 0 and 200°C

Abstract

The thermodynamic solubility products of CaSO4 and the free energies, enthalpies and entropies of the solution process have been obtained from know solubility data between 0 and 200 °C by calculating the activity coefficients of CaSO4 at high temperatures by means of the Bjerrum treatment of ion association. The thermodynamic solubility product of the n-hydrate is then given by K°sp=m2sγ2±anw and the thermodynamic functions are derived from this and tabulated.