| abstract |
The present invention relates to a fused cast refractory product comprising, in percentages by weight on the basis of the oxides and for a total of 100% of the oxides: ZrO2+Hf2O: balance up to 100% 4.5% < SiO2 < 6.0% Al2O3 < 0.80% 0.3% < B2O3 < 1.0% Ta2O5+Nb2O5 < 0.15% Na2O+K2O < 0.1% K2O < 0.04% CaO+SrO+MgO+ZnO+BaO < 0.4% P2O5 < 0.05% Fe2O3+TiO2 < 0.55% other oxide species: < 1.5%, the A/B ratio of the mass contents, Al2O3/B2O3, being between 0.5 and 2.0, the Y2O3 content being less than 0.3%. Application in glass melting furnaces. |