Generalized Electrolyte-UNIQUAC-NRF Model for Calculation Phase Diagram and Solubility of Mixed Electrolyte in Aqueous Solutions

The Electrolyte-UNIQUAC-NRF model is modified and extended to represent the excess Gibbs energy function of multicomponent electrolyte solutions. Using the available experimental meanactivity coefficient of aqueous binary electrolyte systems in the extensive domain of temperatureand molality, the adjustable temperature dependent parameters are obtained for several binary electrolyte systems. Thus, having the binary interaction parameters, the solubility of electrolytes internary aqueous electrolyte solutions are predicted at 298K and higher temperature so that thephase diagram of the salt solubility are obtained for several ternary aqueous salt systems. The results of the prediction of solubilities of salts, osmotic coefficient and vapor pressure of solvent using the present work demonstrate that the generalized Electrolyte-UNIQUAC-NRF model can be successfully applied for the ternary mixed electrolyte systems with very good accuracy.

Keywords:

Electrolyte-UNIQUAC-NRF model , Multicomponent Electrolyte , Activity Coefficient , Osmotic Coefficient , Vapor Pressure , Solubility prediction