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 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 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.

The present disclosure relates to a magnesium-based raw material and a preparation method thereof. According to the technical solution, 40-60 wt % fused magnesia particles, 30-40 wt % fine monoclinic zirconia powder, 5-20 wt % fine zirconium oxychloride powder, 0.5-1.5 wt % calcium hydroxide nanopowder, 0.2-0.5 wt % calcium hydroxide nanopowder, and 0.1-0.3 wt % maleic acid are stirred for 15 min to mix well in a high-speed mixing mill at a constant temperature of 25° C. to obtain a mixed powder; and the mixed powder is mixed through a ball mill at a constant temperature of 25° C. for 3 min, roasted in a high temperature furnace at 250-400° C. for 0.5-3 h, and finally cooled to room temperature.

Exemplary embodiments relate to a batch for producing an unshaped refractory ceramic product, to a method for producing a fired refractory ceramic product, to a fired refractory ceramic product and to the use of an unshaped refractory ceramic product.

A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2 exists entirety or partially in a surface of each of the MgO-containing particles.

The invention concerns a refractory ceramic batch as well as a refractory ceramic product.

A refractory, coarse ceramic product including at least one granular refractory material, has an open porosity of between 22 and 45 vol.-%, in particular of between 23 and 29 vol.-%, and a grain structure of the refractory material, wherein the medium grain size fraction with grain sizes of between 0.1 and 0.5 mm is 10 to 55 wt.-%, in particular 35 to 50 wt.-%, and wherein the remainder of the grain structure is a finest grain fraction with grain sizes of up to 0.1 mm and/or coarse-grain fraction with grain sizes of more than 0.5 mm.

A method for producing a granular material from sintered magnesia by sintering of pressed articles, in particular pellets, from MgO powder, preferably from caustic MgO powder, and subsequent mechanical comminution of the pressed articles, the sintering being carried out in such a way that the granular material has a grain porosity (total porosity), according to DIN EN 993-1:1195-04 and DIN EN 993-18:1999-01, of from 15 to 38 vol %, preferably 20 to 38 vol %. Also, a batch for producing a coarse ceramic, refractory, shaped or unshaped product containing the porous sintered magnesia, to such a product produced from the batch and to a method for its production, to a lining, in particular a working casing and/or a backing, of a large-volume industrial furnace, the lining, in particular the working casing and/or the backing, having at least one such product, as well as to such an industrial furnace.