Patent ID: 8796167

Claim:
A fused cast refractory product comprising, in percentages by weight based on the oxides and for a total of 100% of the oxides: ZrO 2 +Hf 2 O: complement to 100% 4.5%<SiO 2 <6.0% 0.80%≦Al 2 O 3 <1.10% 0.3%<B 2 O 3 <1.5% Ta 2 O 5 +Nb 2 O 5 <0.15% Na 2 O+K 2 O<0.1% K 2 O<0.04% CaO+SrO+MgO+ZnO+BaO<0.4% P 2 O 5 <0.05% Fe 2 O 3 +TiO 2 <0.55% other oxide species: <1.5%, the ratio “A/B” of the contents by weight Al 2 O 3 /B 2 O 3 being between 0.75 and 1.6.