Study on application of ion-exchange reaction to synthesis of new inorganic compounds

Abstract

 Ion-exchange reaction with inorganic compounds was attempted to prepare new compounds and to adsorb anion or rare earth metal ions in solution. The Li⁺ ion in LiTaWO₆ with the trirutile-type structure was ion-exchanged completely with proton to yield HTaWO₆·nH₂O. The protonated compounds, HTaWO₆·nH₂O had high selectivity for incorporation of Li⁺ ion and was strong brønsted acid. The Rb⁺ ion in Rb₈Nb₂₂O₅₉ with a tunnel structure was ion-exchanged with proton and Na⁺ ion, and the Cs⁺ ion in Cs₃Fe_0.5Nb_5.5O₁₆ with a tunnel structure was replaced partially with Rb⁺ ion by immersing in molten salt. The pyrolysis products of Y₂(OH)_6−x(NO₃)_x·nH₂O exhibited good performance of adsorption for Cl⁻ ion in acidic solution. 13 inorganic compounds were attempted to adsorb rare earth metal ions in solution, and both of γ-ZrP and HAp had high ability for adsorption of rare earth metals in solution.