Soda lime zirconia silicate glasses as prospective hosts for zirconia-containing radioactive wastes

Na2O–CaO–ZrO2–SiO2 glass compositions with ZrO2 contents of up to 20 mol% were melted. Up to 12.3 mol% ZrO2 could be dissolved into the glasses. Melting temperatures ⩾1450 °C were required to remove seed and produce a melt that could be cast. Addition of ZrO2 caused an increase in the glass transition and crystallization temperatures. Glasses crystallized at temperatures ⩾1050 °C with Keldyshite and Parakeldyshite (Na2O · ZrO2 · 2SiO2) as the crystalline phases. Addition of up to 4.6 mol% ZrO2 caused an increase in the hydrolytic resistance of the glass, with further additions having little effect. The suitability of these glasses as hosts for ZrO2-containing radioactive wastes is discussed.