Thermodynamic investigation of the CaO—Al2O3— CaSO4—CaCO3-H2O closed system at 25°C and the influence of Na2O

Abstract

The CaO—Al₂O₃— CaSO₄—CaCO₃-H₂O closed system at 25°C has been investigated by thennodynamic calculations: eight isothermally invariant points have been determined. From these points, the composition of the solutions coexisting at equilibrium with ettringite, calcium hemicarboaluminate and/or calcium monocarboaluminate has been defined. The influence of alkalis on solubility relations and phase stability is outlined on the basis of preliminary calculations.