Patent ID: 8765620

Claim:
A fused and cast refractory product comprising, in percentages by weight based on oxides and for a total of 100%: ZrO 2 : complement to 100%, Hf 2 O: <5%, SiO 2 : 2% to 10%, 0.9%<Y 2 O 3 +CeO 2 +CaO+MgO≦4.0%, B 2 O 3 : ≦4.5%, B 2 O 3 : ≧0.09×(Y 2 O 3 +⅓(CeO 2 +CaO+MgO))×SiO 2 , Al 2 O 3 : 0.3% to 2.0%, Na 2 O+K 2 O: ≦0.5%, P 2 O 5 : <0.05%, Fe 2 O 3 +TiO 2 : <0.55%, other species: <1.0%, provided that a Y 2 O 3 content is greater than or equal to 0.8%.