ESTIMATION OF SALT SOLUBILITIES IN HYDROTHERMAL SYSTEMS

In this work we analyze the calculation of the solubility of salts at high temperatures and pressures. The prediction of solubility constant s relies on the knowledge of the standard properties of the ions in wa ter, while the calculation of ion concentration and speciation in solu tion at saturation requires a method to estimate activity coefficients and association constants. We discuss the achievements and limitation s of the ion-specific interaction and the mean spherical models to est imate activity coefficients in pure and mixed electrolyte systems. We emphasizes the importance of simple models depending on few molecular parameters anti having a reasonable physical behaviour as a function o f pressure and temperature.