Studies of Water‐Salt Systems at Elevated Temperatures and Pressures

Abstract Several basic types of phase diagrams for binary and ternary water‐salt systems may be elucidated from experimental investigations of phase equilibria to elevated temperatures (up to 550 °C) and pressures (up to 2.5 kbar). The temperature dependence of some physico‐chemical quantities as the concentrations of solutions in monovariant equilibria, molar volumes, electrical conductivities and spectroscopic properties are carefully analysed. The results indicate a clearly different behaviour between dilute and concentrated hydrothermal solutions. The salt concentrations where the transition between water like and melt like characteristics in 1:1, 1:2, 2:2 electrolyte solutions occurs are determined and the correlation of these concentrations with the molecular characteristics of electrolytes are established.