Patent ID: 8822362

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% 4.0%<SiO 2 <6.5% Al 2 O 3 ≦0.75% 0.2%<B 2 O 3 <1.5% 0.3%<Ta 2 O 5 Nb 2 O 5 +Ta 2 O 5 <1.4% Na 2 O+K 2 O<0.2% BaO<0.2% P 2 O 5 <0.15% 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 less than 1.50.