| 摘要 |
A high electric resistant cast refractory having high-zirconia is provided to reduce exfoliation at high temperature in order to furnish the cast refractory with stability, and to improve electric resistance at high temperature of the cast refractory. A cast refractory which is controlled for the viscosity of the glass phase at near 1,000deg.C and for remnant stress on the surface comprises: 87-96% by weight of ZrO2, 0.1-0.8% by weight of Al2O3, 3-10% by weight of SiO2, less than 0.05% by weight of Na2O, 0.01-0.2% by weight of K2O, 0.1-1.0% by weight of B2O3, 0.1-0.5% by weight of BaO, less than 0.05% by weight of SrO, 0.01-0.15% by weight of CaO, 0.05-0.5% by weight of Y2O3, up to 0.1% by weight of MgO and totally up to 0.03% by weight of Fe2O3 and TiO2, and substantially excludes P2O5 and CuO (less than 0.01% by weight), while the cast refractory has electrical resistance of 200Фcm after maintaining at 1,500deg.C for 12 hours. The other cast refractory which is controlled for the viscosity of the glass phase at near 1,000deg.C and for remnant stress on the surface comprises: 88-96% by weight of ZrO2, 0.1-0.8% by weight of Al2O3, 3-9% by weight of SiO2, less than 0.04% by weight of Na2O, 0.01-0.15% by weight of K2O, 0.1-0.7% by weight of B2O3, 0.1-0.5% by weight of BaO, less than 0.05% by weight of SrO, 0.01-0.15% by weight of CaO, 0.05-0.2% by weight of Y2O3, up to 0.05% by weight of MgO and totally up to 0.03% by weight of Fe2O3 and TiO2, and substantially excludes P2O5 and CuO (less than 0.01% by weight), while the cast refractory has electrical resistance of 200Фcm after maintaining at 1,500deg.C for 12 hours. For the remnant stress of the cast refractory, a tensile stress is up to 30MPa, and compressive stress is up to 20MPa. The transition temperature, Tg for the glass phase of the cast refractory is 850-950deg.C.
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