Calculation and Verification for the Thermodynamic Data of 3CaO·3Al2O3·CaSO4

Calcium sulfoaluminate, 3CaO·3Al2O3·CaSO4, has been widely recognized in the realms of high-temperature combustion and cement chemistry. However, the lack of relevant thermodynamic data limits the progress of its research and development. Through comparative calculations using several different approaches, we obtain the thermochemical properties of 3CaO·3Al2O3·CaSO4 in this work, such as its standard formation enthalpy, Gibbs free energy of formation, entropy, and molar heat capacity. With these fundamental data, thermodynamic calculations become possible for reactions involving this mineral. It is found that some reactions proposed in literature to generate this mineral may not proceed thermodynamically.