| 摘要 |
The invention relates to a molten cast refractory product comprising, in weight percentages on the basis of the oxides and relative to a total of 100% of the oxides: ZrO2+Hf2O is the remainder making up 100%, 4.5%<SiO2<6.0%, 0.80%≦̸Al2O3<1.10%, 0.3%<B2O3<1.5%, 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%, and other oxide species <1.5%, the “A/B” ratio of the Al2O3/B2O3 contents by weight being between 0.75 and 1.6. The invention can be applied to glass melting furnaces. |
