Thermodynamic Modeling of the H₂O–NaCl–KCl–AlCl₃ System

The dew point approach is used for the first time to determine the activity of water in the H₂O–NaCl–KCl–AlCl₃ system at 298.15 K and in the constituent ternary subsystems at 298.15 and 323.15 K. A set of parameters for the Pitzer–Simonson–Clegg liquid phase model is proposed that adequately describes vapor–liquid equilibria, along with heat capacities of solutions and solubility in the H₂O–AlCl₃ system from 222.45 to 373.15 K; vapor–liquid equilibria and solubility in the H₂O–NaCl–AlCl₃ and H₂O–KCl–AlCl₃ systems in the range of 273.15 to 363.15 K, along with vapor-liquid equilibria in H₂O–NaCl–KCl–AlCl₃ at 298.15 K. The densities of solutions in the H₂O–NaCl–KCl–AlCl₃ system are measured at 298.15 K, and the resulting values are then compared to those calculated using the Laliberte model.