Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

摘要: Abstract ‘Fused/cast Al2O3–ZrO2–SiO2 (FC-AZS)’ is being considered as ‘glass contact refractory’ within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) aluminosilicate (Al2SiO5) matrix. 27Al and 29Si NMR data suggest that matrix Al occurs in both 4- 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates FC-AZS 6 M HNO3, simulated wastes (500 h exposure), borosilicate melt (975 °C, 800 h exposure) are found 0.38 × 103 μmy−1, 0.13 × 103 μmy−1 4.75 × 103 μmy−1 respectively. A comparison chemical interaction clearly suggests exhibits better durability than AZC refractory (Al2O3–ZrO2–Cr2O3, also similar purpose). Thermal cycling studies indicate retains structural integrity (including compressive strength density) even up 20 cycles.