Developments of Ion-Memorizing Inorganic Ion-Exchangers for Potassium and Bromide Ions

Develepment of Potassium Ion-Memorizing Inorganic Ion-Exchangers (Part 2)

Abstract

To develop potassium ion ion-memorizing inorganic-exchangers, potassium ions of specially synthesized KMo₅O₁₅OH·2H₂O and KNbWO₆ with tunnel structure or K2Mn₂O₈ and KMg₂LiSi₄O₁₀F₂·2H₂O with layered structures were ion-exchanged for sodium ions in sodium chloride aqueous solution, protons in hydrochloric acid aqueous solution, or lithium ions in lithium chloride squeous solution at 70°C.
Sodium ion-exchanged Na_xK₁-_xMo₅O₁₅OH·2H₂O, Na_xK₁-_xMg₂LiSi₄O₁₀F₂·2H₂O and proton-exchanged K₂-_xH_xMn₄O₈ were found to have the selectivity for potassium ions in aqueous solution at room temperature. Especially, it was found that NaMg₂LiSi₄O₁₀F₂·2H₂O has an outstanding selectivity for potassium ions in solution. This mica has the feasibility of a superior potassium ion ionmemorizing ion-exchanger.
To develop bromide ion ion-memorizing ion-exchangers, Pb₁₀(PO₄)₆Br₂-_xCl_x was synthesized and its anion-exchange characteristics of chloride ions in it for bromide ions in aqueous solutions were investigated.