REFRACTORY PRODUCT HAVING HIGH ZIRCONIA CONTENT

摘要

A fused and cast refractory product containing, in weight percentages on the basis of the oxides (for a total of 100%): ZrO: remainder up to 100; HfO: lower than 5; SiO: 2-10; YO+CeO+CaO+MgO: more than 0.9 and no more than 4.0; BO: no more than 4.5; BO: no lower than 0,09×(YO+1/3(CeO+CaO+MgO))×SiO; AlO: 0.3-2.0; NaO+KO: no more than 0.5; PO: lower than 0.05; FeO+TiO: lower than 0.55; other species: lower than 1.0, as long as the YOcontent is no lower than 0.5 wt.% or the CeO+CaO+MgO content is no lower than 2 wt.%. The invention can be used in glass melting furnaces.