Ion Exchange Equilibria for Ternary Systems from Binary Exchange Data

Abstract

Ternary ion exchange equilibria have been predicted from measured binary equilibrium data, using the Wilson equation for solid phase activity coefficients, with a significant reduction in experimental effort. Using the reciprocal relationship and the Hála constraint, predictions have been made from data measured for only two binary pairs with similar accuracy to those made with data from all three binary systems, provided the binary pairs selected both include the most favourably selected ion. The difference between ternary equilibrium predictions and experimental data was within the accuracy of the experimental data itself.