Provided is a refractory product which is not impregnated with pitch or the like, wherein it has higher corrosion-erosion resistance and thermal shock resistance as compared to a refractory product subjected to pitch or the like-impregnation treatment. The refractory product which is not impregnated with tar or pitch is characterized in that, in terms of values of physical properties of a sample of the refractory product as measured after heat-treating the sample in a non-oxidizing atmosphere at 1200° C.: an apparent porosity is 7% or less; a total void volume of pores having a pore diameter of 1 μm or less is 80% or more of an integrated void volume of pores of the entire sample of the refractory product; and a gas permeability is 50×10.sup.−17 m.sup.2 or less.

A method of separating a mixture of used refractory components of different chemistry types obtained from a demolished refractory includes hydrating the mixture of refractory components to destructively hydrate at least some components of the mixture of refractory components, and separating, based on size, the at least some components from other components of the mixture of refractory components.

A method of separating a mixture of used refractory components of different chemistry types obtained from a demolished refractory includes hydrating the mixture of refractory components to destructively hydrate at least some components of the mixture of refractory components, and separating, based on size, the at least some components from other components of the mixture of refractory components.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

A dry backfill for producing a basic molded heavy-clay refractory product, to such a product and a method for producing the same, to a lining of an industrial furnace, and to an industrial furnace.

A method of producing a graphite-containing refractory within which carbon fiber bundles are placed, the graphite constituting 1% to 80% by mass, the method including a bundling step of bundling carbon fibers to form the carbon fiber bundles; a mixing step of mixing a refractory raw material with graphite to prepare a graphite-containing refractory raw material; a pressing step of pressing the graphite-containing refractory raw material in which the carbon fiber bundles are placed to prepare a formed product; and a drying step of drying the pressed product, wherein the bundling step includes bundling 1000 to 300000 of the carbon fibers with a fiber diameter of 1 to 45 μm/fiber to form carbon fiber bundles 100 mm or more in length.

A method of producing a graphite-containing refractory within which carbon fiber bundles are placed, the graphite constituting 1% to 80% by mass, the method including a bundling step of bundling carbon fibers to form the carbon fiber bundles; a mixing step of mixing a refractory raw material with graphite to prepare a graphite-containing refractory raw material; a pressing step of pressing the graphite-containing refractory raw material in which the carbon fiber bundles are placed to prepare a formed product; and a drying step of drying the pressed product, wherein the bundling step includes bundling 1000 to 300000 of the carbon fibers with a fiber diameter of 1 to 45 μm/fiber to form carbon fiber bundles 100 mm or more in length.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.