Effect of B₂O₃ on Iron Phosphate Glass-Ceramic Wasteforms

The effects of doping iron phosphate glass-ceramic wasteforms containing high level waste (HLW) with different B₂O₃ contents on their structures and properties were investigated. The chemical durability of glass-ceramic wasteforms was measured by dissolution rate (DR) method. The structure of the glass-ceramic wasteforms was analyzed by Fourier turning infrared (FTIR) and X-radiation diffraction (XRD). The results show that glass-ceramic wasteforms have the main crystalline phase of monazite. There are great effects of wasteforms on the chemical durability. The 28 d leaching rate of glass-ceramic watesforms is 7.81×10^-9 g/(cm²•min) when 10% (mole percent) Fe₂O₃ is replaced by B₂O₃ in watesforms. Samples exist a large number of PO₄^3-, a small amount of P₂O₇^4- and no PO₃^-. Boron in wasteform samples is present as tetrahedral BO₄ units.