Phase relations in the system NaCl-KCl-H₂O II: Differential thermal analysis of the halite liquidus in the NaCl-H₂O binary above 450°c

Thermal analysis of the halite liquidus in the system NaCl-H₂O has been conducted for NaCl mole fractions (X_NaCl) greater than 0.25 (i.e., > 50 wt. % NaCl) at pressures between 0.3 and 4.1 kb and temperatures greater than 450°C. The position of the liquidus was located by differential thermal analysis (DTA) of cooling scans only, as heating scans did not produce definitive DTA peaks. The dP/dT slope of the liquidus is positive and steep at high pressures, but at high X_NaCl, and pressures below 0.5 kb it appears to reverse slope and intersects the three-phase curve (liquid-halite-vapour) at a shallow angle. However, due to the complex nature of the DTA signal when P