REFRACTORY PRODUCT HAVING A HIGH ZIRCONIA CONTENT

摘要

A fused and cast refractory product including, in mass percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2 + Hf2O: balance to 100%; SiO2: 7.0% to 11.0%; Al2O3: 0.2% to 0.7%; Na2O + K2O: <0.10%; B2O3: 0.3% to 1.5%; CaO + SrO + MgO + ZnO + BaO: <0.4%; P2O5: <0.15%; Fe2O3 + TiO2: <0.55%; Other oxide species: <1.5%; the mass content of a dopant selected from Nb2O5, Ta2O5 and mixtures thereof being of less or equal to 1.0%, and the A/B ratio of the Al2O3/B2O3 mass contents being less than or equal to 2.0.