| 摘要 |
High zirconia casting refractories with high electric resistance are provided to show electric resistance of 200Ф.cm or greater after a 12-hour holding period at 1500°C and to prevent a peeling phenomenon in a heating process. High zirconia casting refractories are composed of 85-95wt% of ZrO2, 4-12wt% of SiO2, 0.1-0.8wt% of Al2O3, 0.04wt% of Na2O, 0.01-0.15wt% of K2O, 0.1-1.5wt% of B2O3, 0.01-0.2wt% of CaO, 0.4wt% of BaO, 0.2wt% of SrO and 0.05-0.4wt% of Y2O3 and 0.3wt% of Fe2O3+TiO2. The high zirconia casting refractories does not include either P2O5 or CuO. The molar ratio of glass-forming oxide such as SiO2 and B2O3 to glass modifying oxide such as Na2O, K2O, CaO, MgO, SrO and BaO is 20-100. The electric resistance of the high zirconia casting refractories is 200Ф.cm or greater after a 12-hour holding period at 1500°C.
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