Mössbauer and FTIR studies on antimony and tellurium loaded iron phosphate glass

Immobilisation of heavy metals within the glass matrix imposes the challenge of vitrifying maximum amount of waste in minimum possible volume. Iron phosphate glasses (IPG) offer processing of higher specific volumes of wastes at melting temperatures (950 °C - 1100 °C) lower than that of borosilicate glass. Interestingly, it has also been found that IPG modified with different metal ions get chemically more durable than the base glass owing to the reduction of long chain P-O-P linkages since they are more prone to hydrolysis. Moreover, such structural modification reduces the corrosion of refractory oxide crucibles and Inconel alloys used in the vitrification of glasses. A standardized 40Fe₂O₃-60P₂O₅ composition for base IPG has been universally accepted for nuclear waste disposal. An increased solubility of heavy metals and better chemical compatibility with phosphates, sulphates and chromium oxides have been reported for IPG as compared to the present day standard of borosilicate glasses. There are reports on the vitrification of different waste forms including UO₂, Cs₂O, MoO₃, SrO and BaO. Invariably and inevitably, there is a change in the structure of the glass matrix following such inclusions.In the present manuscript, we report Moessbauer and FTIR studies on two representative IPG (40-60) loaded with 10mol% of Sb and co-loaded with 15 mol% of Sb and Te