Abstract: A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al4O4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al2O3, a free C, and other refractory component; a sum of Al4O4C, Al2O3, and the Al component as a metal is 85% or more by mass; and a content of Al4O4C (Al4O4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2: 1.0?C/(Al4O4C×0.038+Al×0.33) (Equation 1) and 1.0?C/(Al4O4C×0.13+Al×0.67) (Equation 2).

Abstract: A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al4O4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al2O3, a free C, and other refractory component; a sum of Al4O4C, Al2O3, and the Al component as a metal is 85% or more by mass; and a content of Al4O4C (Al4O4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2: 1.0?C/(Al4O4C×0.038+Al×0.33)??(Equation 1) and 1.0?C/(Al4O4C×0.13+Al×0.67)??(Equation 2).

Abstract: In order to suppress destruction of a refractory which contains a metal aluminum, the refractory is a refractory for steel casting which includes a refractory material containing a free carbon in the range of 1 to 10% by mass, both inclusive, a metal aluminum in the range of 1 to 15% by mass, both inclusive, and a metal oxide in a balance. The refractory for steel casting satisfies the following Equation 1: 0.31×Al?(P?4)/D (Equation 1), with a metal aluminum content in the refractory designated by Al % by mass, an apparent porosity thereof designated by P %, and a bulk density thereof designated by D.

Abstract: It is an object to provide an aluminum oxycarbide composition capable of suppressing oxidation of Al4O4C during use to maintain advantageous effects of Al4O4C for a long time. In an aluminum oxycarbide composition comprising Al4O4C crystals, the Al4O4C crystals have an average diameter of 20 ?m or more, based on an assumption that a cross-sectional area of each Al4O4C crystal during observation of the aluminum oxycarbide composition in an arbitrary cross-section thereof is converted into a diameter of a circle having the same area as the cross-sectional area. This aluminum oxycarbide composition can be produced by subjecting a carbon-based raw material and an alumina-based raw material to melting in an arc furnace and then cooling within the arc furnace.

Abstract: Disclosed is a method of producing a plate brick, which comprises: adding an organic binder to a refractory raw material mixture containing aluminum and/or an aluminum alloy; kneading them; forming the kneaded mixture into a shaped body; and burning the shaped body in a nitrogen gas atmosphere at a temperature of 1000 to 1400° C., wherein: when a temperature of a furnace atmosphere is 300° C. or more, the atmosphere is set to a nitrogen gas atmosphere; and when the temperature of the furnace atmosphere is 1000° C. or more, an oxygen gas concentration in the atmosphere is maintained at 100 volume ppm or less, and a sum of a carbon monoxide gas concentration and a carbon dioxide gas concentration is maintained at 1.0 volume % or less.

Abstract: Provided is an aluminum oxycarbide composition production method capable of increasing a yield of Al4O4C while reducing a content rate of Al4C3 and achieving high productivity, and an aluminum oxycarbide composition. The method comprises: preparing a blend substantially consisting of a carbon-raw material having a mean particle diameter of 0.5 mm or less and an alumina-raw material having a mean particle diameter of 350 ?m or less, wherein a mole ratio of the carbon-raw material to the alumina-raw material (C/Al2O3) is in a range of 0.8 to 2.0; homogeneously mixing the blend to allow a variation in C component to fall within ±10%; and melting the obtained mixture in an arc furnace at 1850° C. or more.

Abstract: It is an object to provide an aluminum oxycarbide composition capable of suppressing oxidation of Al4O4C during use to maintain advantageous effects of Al4O4C for a long time. In an aluminum oxycarbide composition comprising Al4O4C crystals, the Al4O4C crystals have an average diameter of 20 ?m or more, based on an assumption that a cross-sectional area of each Al4O4C crystal during observation of the aluminum oxycarbide composition in an arbitrary cross-section thereof is converted into a diameter of a circle having the same area as the cross-sectional area. This aluminum oxycarbide composition can be produced by subjecting a carbon-based raw material and an alumina-based raw material to melting in an arc furnace and then cooling within the arc furnace.

Abstract: Provided is a zirconia-mullite refractory raw material which is less likely to undergo alternation and microstructural degradation under high-temperature conditions, and low in thermal expansion rate, so as to have thermal shock resistance and corrosion resistance. The zirconia-mullite refractory raw material comprises crystalline zirconia and mullite as primary components, with the remainder being corundum and/or a matrix glass, wherein the crystalline zirconia includes a eutectic zirconia crystal having a grain size of 1.0 ?m or less, and has a maximum grain size of 30 ?m or less, and the matrix glass is contained in an amount of 5 mass % or less. The zirconia-mullite refractory raw material has a chemical composition comprising 30 to 55 mass % of ZrO2, 30 to 55 mass % of Al2O3 and 10 to 25 mass % of SiO2, wherein each of the chemical components falls within a primary phase region of ZrO2 in an Al2O3—ZrO2—SiO2 system phase diagram.

Abstract: Provided is an aluminum oxycarbide composition production method capable of increasing a yield of Al4O4C while reducing a content rate of Al4C3 and achieving high productivity, and an aluminum oxycarbide composition. The method comprises: preparing a blend substantially consisting of a carbon-raw material having a mean particle diameter of 0.5 mm or less and an alumina-raw material having a mean particle diameter of 350 ?m or less, wherein a mole ratio of the carbon-raw material to the alumina-raw material (C/Al2O3) is in a range of 0.8 to 2.0; homogeneously mixing the blend to allow a variation in C component to fall within ±10%; and melting the obtained mixture in an arc furnace at 1850° C. or more.

Abstract: Disclosed is a method of producing a plate brick, which comprises: adding an organic binder to a refractory raw material mixture containing aluminum and/or an aluminum alloy; kneading them; forming the kneaded mixture into a shaped body; and burning the shaped body in a nitrogen gas atmosphere at a temperature of 1000 to 1400° C., wherein: when a temperature of a furnace atmosphere is 300° C. or more, the atmosphere is set to a nitrogen gas atmosphere; and when the temperature of the furnace atmosphere is 1000° C. or more, an oxygen gas concentration in the atmosphere is maintained at 100 volume ppm or less, and a sum of a carbon monoxide gas concentration and a carbon dioxide gas concentration is maintained at 1.0 volume % or less.

Abstract: Provided is a zirconia-mullite refractory raw material which is less likely to undergo alternation and microstructural degradation under high-temperature conditions, and low in thermal expansion rate, so as to have thermal shock resistance and corrosion resistance. The zirconia-mullite refractory raw material comprises crystalline zirconia and mullite as primary components, with the remainder being corundum and/or a matrix glass, wherein the crystalline zirconia includes a eutectic zirconia crystal having a grain size of 1.0 ?m or less, and has a maximum grain size of 30 ?m or less, and the matrix glass is contained in an amount of 5 mass % or less. The zirconia-mullite refractory raw material has a chemical composition comprising 30 to 55 mass % of ZrO2, 30 to 55 mass % of Al2O3 and 10 to 25 mass % of SiO2, wherein each of the chemical components falls within a primary phase region of ZrO2 in an Al2O3—ZrO2—SiO2 system phase diagram.