An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

An unfired, refractory molded body (1), especially a plate, especially for thermal insulation of molten metal and/or an ingot solidifying from molten metal, that includes a binding agent matrix (2) of a set binder and aggregate grains (3) of biogenic silicic acid, preferably of rice husk ash, which are incorporated into the binding agent matrix (2), wherein the binding agent matrix (2) consists of silica gel, as well as a process for its production and its usage.

Large steel ingot casting is accomplished with a top suspended induction heating device supplied with variable power and variable frequency from a power source. By the induction heating and stirring provided by the top suspended induction heating device, metal solidification advances progressively upwards from bottom to top, and the upper molten metal in a riser part compensates for shrinkage of the lower solidified metal in the main part. Inclusions are selectively moved out of the molten metal by a variable electromagnetic stirring force and the formation of casting defects is suppressed.

An unfired, refractory molded body (1), especially a plate, especially for thermal insulation of molten metal and/or an ingot solidifying from molten metal, that includes a binding agent matrix (2) of a set binder and aggregate grains (3) of biogenic silicic acid, preferably of rice husk ash, which are incorporated into the binding agent matrix (2), wherein the binding agent matrix (2) consists of silica gel, as well as a process for its production and its usage.

A heat insulating plate (1), preferably a covering plate (5a;b), especially for thermal isolation of molten metal, especially of molten steel, in a metallurgical vessel (6), wherein the plate (3) includes a binding agent matrix (2) of at least one, set, temporary, organic binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains (3) are incorporated into the binding agent matrix (2), and to a method for production of the plate (1) and its use.

A heat insulating plate (1), preferably a covering plate (5a;b), especially for thermal isolation of molten metal, especially of molten steel, in a metallurgical vessel (6), wherein the plate (3) includes a binding agent matrix (2) of at least one, set, temporary, organic binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains (3) are incorporated into the binding agent matrix (2), and to a method for production of the plate (1) and its use.

An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

A method for producing a feeder element is described. The method includes (a) producing composite particles having a particle size of less than 2 mm in a matrix encapsulation method with the following steps: (a1) producing droplets of a suspension from at least (i) one or more refractory substances, (ii) one or more of fillers having a bulk density in the range from 10 to 350 g/L, expandants, and pyrolysable fillers, (iii) as continuous phase, a solidifiable liquid, (a2) solidifying the droplets with the refractory substance(s) and density-reducing substance(s) are encapsulated therein, (a3) treating the hardened droplets to form composite particles, (b) mixing the composite particles with a binder and, optionally, further constituents to give a feeder composition, (c) shaping and curing the feeder composition to give a feeder element. Also described are a method for producing refractory composite particles and the use of the composite particles.