Preparation and aqueous durability of Sr incorporation into rutile TiO₂

Abstract

TiO₂ was employed as the waste form for disposal of simulated nuclide Sr. Preparation of Sr bearing rutile was explored under different sintering temperatures and Sr contents. The optimal treatment temperature was confirmed as 1 300 °C for the incorporation of SrO in rutile TiO₂. Perovskite type SrTiO₃ was prepared as the resultant product. The limited containment capacity of SrO in rutile was speculated to be 56.5wt%. As the SrO content increases, the as-synthesized sample exhibits more porosity because SrTiO₃ phase demonstrates higher density than rutile and SrO. The 28 day normalized leaching rate (LRi) of Sr and Ti will decrease congruously as the SrO incorporation increases. The LR_Sr value is lower than 0.1 g·m^-2·d^-1, which is about 3 orders of magnitude higher than the LR_Ti value.

Keywords

rutile / Sr / immobilization / leaching rate

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