Sintering of SrB₂Si₂O₈ glass-ceramics and their Sr immobilization

Abstract

A method of low-temperature liquid-phase sintering was used to prepare SrB₂Si₂O₈ glass-ceramics in order to simulate immobilization of ⁹⁰Sr, and the SrO–B₂O₃ system as a flux could avoid new impurities to be introduced into the solidified body. The sintering behaviors, mechanical properties and solidification behaviors of SrB₂Si₂O₈ were investigated. The crystalline phase of SrB₂Si₂O₈ was formed by liquid phase sintering at 1223 K. Additionally, adding Ca²⁺ improves the sintering behavior and mechanical properties of samples. The stable mineral phase of SrB₂Si₂O₈ is helpful to achieve a perfect effect on the immobilization of Sr. The Sr²⁺ leak mainly from the glass phase. Our results suggest that the key to resisting the leaking of Sr²⁺ is to form not only stable mineral phases but also stable glass phases.