Phase Evolution of Sphene Based Ceramics during Annealing

CaO-TiO2-SiO2 (sphene) based ceramics has been prepared from a powder mixture (calcite, rutile and amorphous silica) using vibro-milling for homogenization and activation of the precursors. Sphene can be used for nuclear waste disposal. Although many approaches like multi-barrier, glass and ceramic waste forms are available for the nuclear waste disposal, the ceramic waste form is still attractive. In ceramics, because of its synthetic approach of immobilizing the radioactive waste, the radioactive nuclides are incorporated into solid solutions in an assemblage of synthetic mineralogical phase. Among various ceramic waste forms, synthetic rock (synroc) - sphene (CaTiSiO5) is currently receiving significant attention. The evolution of the phase composition during thermal treatment was investigated by thermal analyses and X-ray diffraction measurements. Also, morphology of was determined by scanning electron microscopy microscopy techniques.