The pH Titration Study of Lithium Ion Adsorption on λ-MnO2

Abstract
The pH titration curves of λ-MnO2 showed apparently dibasic acid character toward Li+ ions, but a monobasic acid character toward Na+, K+, Rb+, and Cs+ ions. The adsorptive capacities of alkali metal ions increased in the order; K+, Rb+, Cs++<+ at pH 10. Overall equilibrium constants were calculated by a simplified Gaines-Thomas equation from the titration curves based on the ion-exchange mechanism. Thermodynamic data were derived for the system of (0.1-M LiCl+LiOH)(1 M=1 mol dm−3) at different temperatures. Effects of ionic strength and adsorption temperature on the lithium ion adsorptivity were studied using (LiCl+LiOH) and (KCl+LiOH) solutions.