Ion exchange in fused salts. Part VII. Ion-exchange isotherms for thallium(I)–potassium and rubidium–potassium on crystalline zirconium phosphate in molten thallium nitrate–potassium nitrate and rubidium nitrate–potassium nitrate mixtures at 360 °C

Abstract

Ion-exchange isotherms for Tl⁺–K⁺ and Rb⁺–K⁺ on crystalline zirconium phosphate in molten Tl[NO₃]–K[NO₃] and Rb[NO₃]–K[NO₃] mixtures are almost fully reversible processes which occur in several steps either via a two-phase transition or a solid–solution mechanism. There is a strong dependence of the gradients of the isotherms on the polarisability of the exchanging cations, and some of the equilibrium constants have been calculated.