Abstract: A high zirconia electrically-fused cast refractory has a chemical composition including more than 95% by mass and 98% by mass or less of ZrO2, 0.1 to 1.5% by mass of Al2O3, 1 to 2.5% by mass of SiO2, 0 to 0.1% by mass of K2O, 0.01 to 0.3% by mass of Na2O and K2O in total, 0.02 to 0.4% by mass of B2O3, 0.01 to 0.6% by mass of BaO, 0.01 to 0.4% by mass of SnO2, 0.3% by mass or less of Fe2O3 and TiO2 in total, and 0.04% by mass or less of P2O5, wherein the contents of B2O3 and SnO2 satisfy the following Formulas (1) and (2): 0.20?(SnO2/B2O3)<6.5??(1) 0.14% by mass?(CSnO2+CB2O3/2)?0.55% by mass??(2): In Formula (2), CSnO2 represents the content of SnO2, and CB2O3 represents the content of B2O3, expressed in % by mass in the refractory.

Abstract: The present invention provides a high alumina fused cast refractory that is easily produced and has low porosity and high corrosion resistance, and a method of producing the same. The high alumina fused cast refractory of the present invention has the following chemical composition: 95.0 mass % to 99.5 mass % Al2O3, 0.20 mass % to 1.50 mass % SiO2, 0.05 mass % to 1.50 mass % B2O3, 0.05 mass % to 1.20 mass % MgO and balance. The method of producing the high alumina fused cast refractory of the present invention includes obtaining a mixture by mixing an Al2O3 source material, a SiO2 source material, a B2O3 source material and an MgO source material, and fusing the mixture.

Abstract: The present invention provides a high alumina fused cast refractory that is easily produced and has low porosity and high corrosion resistance, and a method of producing the same. The high alumina fused cast refractory of the present invention has the following chemical composition: 95.0 mass % to 99.5 mass % Al2O3, 0.20 mass % to 1.50 mass % SiO2, 0.05 mass % to 1.50 mass % B2O3, 0.05 mass % to 1.20 mass % MgO and balance. The method of producing the high alumina fused cast refractory of the present invention includes obtaining a mixture by mixing an Al2O3 source material, a SiO2 source material, a B2O3 source material and an MgO source material, and fusing the mixture.

Abstract: A high zirconia electrically fused cast refractory having long time durability with less cracking during production and in the course of temperature rising, excellent in productivity, less forming zircon crystals in the refractory itself and even in contact with molten glass, excellent in bubble foamability to molten glass, less generating cracks even undergoing heat cycles during operation of a glass melting furnace. A high zirconia electrically fused cast refractory comprises, as chemical component, 85 to 95% by weight of ZrO2, 0.4 to 2.5% by weight of Al2O3, 3.5 to 10.0% by weight of SiO2, 0.05% by weight or more of Na2O, 0.05 to 0.7% by weight of Na2O and K2O in total, 0.01 to 0.04% by weight of B2O3, 0.1 to 3.0% by weight of SrO or BaO when one of BaO and SrO is contained, 0.1% by weight or more of SrO and 0.1 to 3.0% by weight of SrO and BaO in total when both of BaO and SrO are contained, 0.01 to 0.2% by weight of CaO, 0.1% by weight or less of MgO, 0.01 to 0.7% by weight of SnO2, 0.

Abstract: A high zirconia electrically fused cast refractory of high electric resistance having long time durability, less suffering from cracking during production and upon temperature rising, excellent in productivity, less forming zircon crystals even upon heating the refractory in itself and when the refractory is in contact with molten glass, generating less cracks even when undergoing heat cycles during operation of a glass melting furnace is provided. A high zirconia electrically fused cast refractory has, as chemical components, 85 to 95% by weight of ZrO2, 0.1 to less than 0.8% by weight of Al2O3, 3.5 to 10.0% by weight of SiO2, less than 0.05% by weight of Na2O and K2O in total, 0.1 to 1.5% by weight of B2O3, 0.1% by weight or less of MgO, 0.01 to 0.2% by weight of CaO, in the case where any one of BaO and SrO is contained, from 0.05 to 3.0% by weight of BaO or 0.01 to 3.0% by weight of SrO, or in the case where both of them are contained, 0.01% by weight or more of SrO and from 0.01% to 3.

Abstract: A high zirconia electrically fused cast refractory having long time durability with less cracking during production and in the course of temperature rising, excellent in productivity, less forming zircon crystals in the refractory itself and even in contact with molten glass, excellent in bubble foamability to molten glass, less generating cracks even undergoing heat cycles during operation of a glass melting furnace. A high zirconia electrically fused cast refractory comprises, as chemical component, 85 to 95% by weight of ZrO2, 0.4 to 2.5% by weight of Al2O3, 3.5 to 10.0% by weight of SiO2, 0.05% by weight or more of Na2O, 0.05 to 0.7% by weight of Na2O and K2O in total, 0.01 to 0.04% by weight of B2O3, 0.1 to 3.0% by weight of SrO or BaO when one of BaO and SrO is contained, 0.1% by weight or more of SrO and 0.1 to 3.0% by weight of SrO and BaO in total when both of BaO and SrO are contained, 0.01 to 0.2% by weight of CaO, 0.1% by weight or less of MgO, 0.01 to 0.7% by weight of SnO2, 0.

Abstract: A high zirconia electrically fused cast refractory of high electric resistance having long time durability, less suffering from cracking during production and upon temperature rising, excellent in productivity, less forming zircon crystals even upon heating the refractory in itself and when the refractory is in contact with molten glass, generating less cracks even when undergoing heat cycles during operation of a glass melting furnace is provided. A high zirconia electrically fused cast refractory has, as chemical components, 85 to 95% by weight of ZrO2, 0.1 to less than 0.8% by weight of Al2O3, 3.5 to 10.0% by weight of SiO2, less than 0.05% by weight of Na2O and K2O in total, 0.1 to 1.5% by weight of B2O3, 0.1% by weight or less of MgO, 0.01 to 0.2% by weight of CaO, in the case where any one of BaO and SrO is contained, from 0.05 to 3.0% by weight of BaO or 0.01 to 3.0% by weight of SrO, or in the case where both of them are contained, 0.01% by weight or more of SrO and from 0.01% to 3.

Abstract: [Problems] To provide a high zirconia fused cast refractory that suffers less cracks in production and on heating, has excellent productivity, is hard to form zircon crystals with the refractory solely and under conditions where the refractory is in contact with molten glass, is hard to suffer cracks on receiving heat cycles in operation of a glass melting furnace, and has durability for a prolonged period of time. [Solution to Problems] A high zirconia fused cast refractory containing, as chemical components, from 85 to 95% by weight of ZrO2, from 0.4 to 2.5% by weight of Al2O3, from 3.5 to 10% by weight of SiO2, from 0.05 to 1% by weight in total of Na2O and K2O, more than 0.04% by weight and 1% by weight or less of B2O3, 0.02% by weight or less of P2O5, 0.05% by weight or less of MgO, from 0.01 to 0.2% by weight of CaO, in the case where any one of SrO and BaO is contained, from 0.3 to 3% by weight of SrO or more than 0.

Abstract: [Problems] To provide a high zirconia fused cast refractory that suffers less cracks in production and on heating, has excellent productivity, is hard to form zircon crystals with the refractory solely and under conditions where the refractory is in contact with molten glass, is hard to suffer cracks on receiving heat cycles in operation of a glass melting furnace, and has durability for a prolonged period of time. [Solution to Problems] A high zirconia fused cast refractory containing, as chemical components, from 85 to 95% by weight of ZrO2, from 0.4 to 2.5% by weight of Al2O3, from 3.5 to 10% by weight of SiO2, from 0.05 to 1% by weight in total of Na2O and K2O, more than 0.04% by weight and 1% by weight or less of B2O3, 0.02% by weight or less of P2O5, 0.05% by weight or less of MgO, from 0.01 to 0.2% by weight of CaO, in the case where any one of SrO and BaO is contained, from 0.3 to 3% by weight of SrO or more than 0.

Abstract: A high-zirconia cast refractory material which contains 85-95 wt % of ZrO2, 4-12 wt % of SiO2, 0.1 to less than 0.8 wt % of Al2O3, less than 0.04 wt % of Na2O, 0.01-0.15 wt % of K2O, 0.1-1.5 wt % of B2O3, 0.01-0.2 wt % of CaO, less than 0.4 wt % of BaO, less than 0.2 wt % of SrO, 0.05-0.4 wt % of Y2O3, and 0.3 wt % or less of Fe2O3 and TiO2 together, but does not substantially contain CuO and P2O5 (less than 0.01 wt %), such that the molar ratio of the glass-forming oxides (such as SiO2 and B2O3) to the glass-modifying oxides (such as Na2O, K2O, CaO, MgO, SrO, and BaO) is 20-100, said refractory material having an electric resistance being 200 ?·cm or higher after standing for 12 hours at 1500° C.

Abstract: A high-zirconia cast refractory material which contains 85-95 wt % of ZrO2, 4-12 wt % of SiO2, 0.1 to less than 0.8 wt % of Al2O3, less than 0.04 wt % of Na2O, 0.01-0.15 wt % of K2O, 0.1-1.5 wt % of B2O3, 0.01-0.2 wt % of CaO, less than 0.4 wt % of BaO, less than 0.2 wt % of SrO, 0.05-0.4 wt % of Y2O3, and 0.3 wt % or less of Fe2O3 and TiO2 together, but does not substantially contain CuO and P2O5 (less than 0.01 wt %), such that the molar ratio of the glass-forming oxides (such as SiO2 and B2O3) to the glass-modifying oxides (such as Na2O, K2O, CaO, MgO, SrO, and BaO) is 20-100, said refractory material having an electric resistance being 200 ?·cm or higher after standing for 12 hours at 1500° C.

Abstract: A crystalline inorganic fiber or molded body thereof is thermally treated in gas atmosphere containing chlorine. The crystalline inorganic fiber or molded body thereof contains small impurities such as Fe, Cu and Ni. For example, Fe is 15 ppm or less, Cu is 1 ppm or less, and Ni is 0.5 ppm or less.

Abstract: Disclosed is a method of manufacturing aluminum nitride, which comprises the steps of preparing a mixed gas consisting essentially of an ammonia gas and at least 0.5% by volume of a hydrocarbon gas, calcining .gamma.-Al.sub.2 O.sub.3 or a precursor thereof at 300.degree. to 1,100.degree. C. so as to prepare the .gamma.-Al.sub.2 O.sub.3 having a moisture content of 1 weight % or less; heating the calcined .gamma.-Al.sub.2 O.sub.3 in the mixed gas at a temperature of 1,200.degree. to 1,700.degree. C., thereby preparing porous aluminum nitride having a specific surface area of 10 m.sup.2 /g or more; and heat-treating the porous aluminum nitride in an atmosphere of an ammonia gas, or a mixed gas of an ammonia gas and an inert gas, at 1600.degree. to 2000.degree. C., so as to make contents of both carbon and oxygen contained in the aluminum nitride 1 weight % or less.

Abstract: A molten fiber material flow is rendered into a plurality of fibers by means of a liquid jet such as water jet in place of a pressurized gas or air. The flow moves downwardly in a vertical direction while the water jet cuts it at an inclined angle. The water jet is formed by a single nozzle or plural nozzles of a flat-jet or round-jet type.