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.

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.

The invention relates to a batch composition for producing a refractory product, a method for producing a refractory product, a refractory product, and to the use of a synthetic raw material.

The invention relates to a batch composition for producing a refractory product, a method for producing a refractory product, a refractory product, and to the use of a synthetic raw material.

Grains for the production of a sintered refractory product, a batch for the production of a sintered refractory product, a process for the production of a sintered refractory product and a sintered refractory product.

A manufacturing method of a low heat-conducting magnesium-aluminium spinel brick includes: (1) evenly mixing sintered magnesia, fused magnesia, magnesium-aluminium spinel and corundum to prepare flame retardant coating raw material mixed powder, adding naphthalene binder to the flame retardant coating raw material mixed powder to prepare the flame retardant coating raw materials after evenly mixing; (2) evenly mixing forsterite, fayalite and magnesia, adding the naphthalene binder to the mixed powder, moulding, drying, and then burning to obtain aggregate composite hortonolite raw materials; adding the naphthalene binder to the aggregate composite hortonolite having granularity ≤5 mm to prepare the thermal insulating layer raw materials after evenly mixing; (3) spacing and loading the flame retardant coating raw materials and the thermal insulating layer raw materials in a mold, pressing into green bricks, keeping the green bricks at a temperature of 110° C. for 24 hours, drying, and burning into magnesium-aluminium spinel bricks.

A manufacturing method of a low heat-conducting magnesium-aluminium spinel brick includes: (1) evenly mixing sintered magnesia, fused magnesia, magnesium-aluminium spinel and corundum to prepare flame retardant coating raw material mixed powder, adding naphthalene binder to the flame retardant coating raw material mixed powder to prepare the flame retardant coating raw materials after evenly mixing; (2) evenly mixing forsterite, fayalite and magnesia, adding the naphthalene binder to the mixed powder, moulding, drying, and then burning to obtain aggregate composite hortonolite raw materials; adding the naphthalene binder to the aggregate composite hortonolite having granularity ≤5 mm to prepare the thermal insulating layer raw materials after evenly mixing; (3) spacing and loading the flame retardant coating raw materials and the thermal insulating layer raw materials in a mold, pressing into green bricks, keeping the green bricks at a temperature of 110° C. for 24 hours, drying, and burning into magnesium-aluminium spinel bricks.

The present disclosure relates to a magnesium-based raw material with low thermal conductivity and low thermal expansion 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. The magnesium-based refractory material prepared has the advantages of relatively low thermal conductivity, low thermal expansion coefficient, excellent dispersibility, and strong resistance to slag penetration and erosion.

A graphite-containing refractory has higher bending strength and fracture energy than known refractories. The graphite-containing refractory has a graphite content of 1% to 80% by mass. 1000 to 300000 carbon fibers with a fiber diameter of 1 to 45 μm/fiber are bundled. The carbon fiber bundle has a length of 100 mm or more and is placed within the graphite-containing refractory to form the same.

A graphite-containing refractory has higher bending strength and fracture energy than known refractories. The graphite-containing refractory has a graphite content of 1% to 80% by mass. 1000 to 300000 carbon fibers with a fiber diameter of 1 to 45 μm/fiber are bundled. The carbon fiber bundle has a length of 100 mm or more and is placed within the graphite-containing refractory to form the same.