Effects of preparation molar ratio on immobilization of Cs and Sr in (H3O)Zr2(PO4)3 through heating in an aqueous solution

Abstract We investigated the effects of the preparation molar ratios (Cs/(H3O)Zr2(PO4)3 and Sr/(H3O)Zr2(PO4)3) on the immobilization of Cs+ and Sr2+ ions in (H3O)Zr2(PO4)3 through heating at 250 °C for 24 h in an aqueous solution using an autoclave. When the preparation molar ratios were 0.4 or lower for Cs and 0.2 or lower for Sr, the immobilization of the corresponding ions occurred almost to completion. On the other hand, for the molar ratios (1.0 for the Cs system and 0.5 for the Sr system) at which all the H3O+ ions in (H3O)Zr2(PO4)3 could be replaced by the Cs+ or Sr2+ ions, the immobilization reaction did not proceed readily.