Liquidus temperature model for Hanford high-level waste glasses with high concentrations of zirconia

A study was conducted on glasses based on a simulated transuranic waste with high concentrations of ZrO2 and Bi2O3 to determine the compositional dependence of primary crystalline phases and liquidus temperature (T-L). Starting from a baseline composition, glasses were formulated by changing mass fractions of Al2O3, B2O3, Bi2O3, CeO2, Li2O, Na2O, P2O5, SiO2, and ZrO2, one at a time, while keeping the remaining components in the same relative proportions as in the baseline glass. Liquidus temperature was measured by heat treating glass samples for 24 h in a uniform temperature furnace. The primary crystalline phase in the baseline glass and the majority of the glasses was zircon (ZrSiO4). A change in the concentration of certain components (Al2O3, ZrO2, Li2O, B2O3, and SiO2) changed the primary phase to baddeleyite (ZrO2), while cerium oxide (CeO2) precipitated from glasses with more than 3 wt% CeO2. Zircon T-L was strongly increased by Al2O3, ZrO2 and CeO2, and slightly by P2O5 and SiO2; decreased strongly by Li2O and Na2O and moderately by B2O3. A first-order model was constructed for T-L as a function of composition for zircon primary crystalline phase glass.