Patent ID: 7655587

Claim:
A fused and cast refractory product with a high zirconia content comprising, as percentages by weight relative to the oxides and for a total of more than 98.5%: ZrO 2 +Hf 2 O: >85%; SiO 2 : 1% to 12%; Al 2 O 3 : 0.1% to 2.4%, with the weight ratio Al 2 O 3 /SiO 2 >0.5; Y 2 O 3 : ≦1%; B 2 O 3 : <1.5%; and a dopant selected from the group consisting of CrO 3 , Nb 2 O 5 , MoO 3 , Ta 2 O 5 , WO 3 , and mixtures thereof, the dopant being present in a weighted quantity such that: 0.2%≦8.84CrO 3 +1.66Nb 2 O 5 +6.14MoO 3 +Ta 2 O 5 +3.81WO 3 .