The glasses containing surrogate of Sludge Batch 4 (SB4) waste with high concentrations of aluminum and ferrous oxides within the waste loading (WL) range of ∼50 to 70 wt.% produced in alumina crucibles in a resistive furnace and in a 236 mm inner diameter cold crucible were examined by X-ray diffraction, electron microscopy and infra-red spectroscopy. At relatively low WLs (50 to 60 w.%) the products remain predominantly vitreous with minor crystalline spinel structure phase corresponding in chemical composition to trevorite-magnetite solid solution. At higher WLs (>60 wt.%) amount of crystalline phases increased significantly and a nepheline phase was observed. The products with WL of 65 to 70 wt.% were spinel/nepheline glass-ceramics. The glass with 60 wt.% WL slowly cooled in accordance with the canister centerline cooling (CCC) conditions contained minor nepheline. Occurrence of nepheline reduces the chemical durability of nuclear waste glasses.

This content is only available via PDF.
You do not currently have access to this content.