Binary and ternary cation exchange in zeolites

Abstract

Summary Na Ca and Na Mg binary exchange isotherms have been determined in zeolite A at 25 and 65°C and total solution phase normalities of 0.2, 0.1, 0.05, 0.01 and 0.005 equiv./dm 3 . The concentration-valency effect was shown to be obeyed. The corrected selectivity coefficient data were fitted to polynomial equations and from these thermodynamic parameters were calculated. Na Ca Mg ternary isotherms were also determined at 65°C using initial solution phase concentrations of 0.10, 0.05 and 0.01 equiv./dm 3 and fixed Ca/Mg ratios of 2:1, 1:1 and 1:2. Finally an attempt has been made to predict ternary exchange data from the corresponding binary isotherms.