Abstract: A refractory brick having durability equal to alumina-magnesia castable materials, which is especially suitable for a ladle for steel making is provided. A refractory brick prepared by using an alumina raw material and a magnesia raw material containing 90% by mass or more of a fine powder of not more than 0.5 mm, press molding and then heat treating at 100° C. or higher and not higher than 1,150° C., the refractory brick containing Al2O3 and MgO in a total sum of 90% by mass or more, from 4 to 16% by mass of MgO, from 0.5 to 5% by mass of SiO2, and Na2O and K2O in a total sum of from 0.3 to 2% by mass, with the remainder being inevitable impurities and Al2O3.

Abstract: An object of the invention is to provide “a hot gunning repair mix” excellent in peeling resistance and hardenable for a short period of time. The hot gunning repair mix according to the invention is a hot gunning repair mix including a refractory raw material containing 20 to 40% by weight of grains having a size of 75 ?m or less and a binder for forming a carbon bond in hot condition, in which a metal powder or an iron alloy powder containing iron (Fe) as a main component and 70% by weight or more of grains having a size of 1.0 mm or less is added in an amount of 5 to 50% by weight based on a total amount of the refractory raw material and the binder.

Abstract: An object is to provide a nonaqueous hot casting repair mix which, while enjoying simple and convenient installation, can substantially reduce hardening time after installation. The hot casting repair mix according to the invention is characterized by containing 5 to 30% by weight of a binder capable of forming a carbon bond in hot condition and 1 to less than 5% by weight of an iron powder and the balance consisting of a refractory aggregate.

Abstract: A refractory brick having durability equal to alumina-magnesia castable materials, which is especially suitable for a ladle for steel making is provided. A refractory brick prepared by using an alumina raw material and a magnesia raw material containing 90% by mass or more of a fine powder of not more than 0.5 mm, press molding and then heat treating at 100° C. or higher and not higher than 1,150° C., the refractory brick containing Al2O3 and MgO in a total sum of 90% by mass or more, from 4 to 16% by mass of MgO, from 0.5 to 5% by mass of SiO2, and Na2O and K2O in a total sum of from 0.3 to 2% by mass, with the remainder being inevitable impurities and Al2O3.

Abstract: A subject for the invention is to provide an unshaped refractory composition having not only high thermal resistance but also improved corrosion resistance and improved unsusceptibility to slag infiltration. The invention is “an unshaped refractory composition comprising: (1) 20 to 70% by weight raw spinel material comprising an MgO—Al2O3 spinel phase and containing 2 to 20% by weight magnesia and/or raw spinel/corundum material comprising an MgO—Al2O3 spinel phase and a corundum phase and containing 2 to 20% by weight magnesia; (2) 3 to 12% by weight raw magnesia material having a particle diameter of 0.3 mm or smaller, containing particle sizes of 75 ?m or smaller in an amount of 55 to 85% by weight, and having a magnesia purity of 90% by weight or higher; (3) 3 to 10% by weight alumina cement having a calcia content lower than 20% by weight; (4) 0.3 to 1.5% by weight ultrafine powder consisting mainly of silica; and (5) a raw alumina material as the remainder”.

Abstract: A subject for the invention is to provide an unshaped refractory composition having not only high thermal resistance but also improved corrosion resistance and improved unsusceptibility to slag infiltration. The invention is “an unshaped refractory composition comprising: (1) 20 to 70% by weight raw spinel material comprising an MgO—Al2O3 spinel phase and containing 2 to 20% by weight magnesia and/or raw spinel/corundum material comprising an MgO—Al2O3 spinel phase and a corundum phase and containing 2 to 20% by weight magnesia; (2) 3 to 12% by weight raw magnesia material having a particle diameter of 0.3 mm or smaller, containing particle sizes of 75 ?m or smaller in an amount of 55 to 85% by weight, and having a magnesia purity of 90% by weight or higher; (3) 3 to 10% by weight alumina cement having a calcia content lower than 20% by weight; (4) 0.3 to 1.5% by weight ultrafine powder consisting mainly of silica; and (5) a raw alumina material as the remainder”.