Abstract: In a melting furnace (1), toxic, volatile chemical compounds from introduced filter dust from industrial incineration units are vaporized at about 1300.degree. C. and forced to leave the reaction space. The non-vaporizing residue forms a glassy melt which is discharged continuously or intermittently from the reaction space. Heating of the melt and of the filter dust is affected by resistance heaters in protective ceramic sheaths (4) above the melt (2). In order to prevent corrosion of the resistance heater protection sheaths (4) by exit gases (7) especially in the flow lee thereof, the exit gases are forced, by partitions (10) and an exit gas extraction pipe (9) with an inlet orifice (16) at a low level, to flow below the resistance heater protection sheaths (4) to an exit gas outlet (5).

Abstract: There is disclosed a process of recovering molten pig iron or steel pre-products from lumpy iron-oxide containing charging substances. The charging substances are reduced to sponge iron in a direct reduction zone, the sponge iron is smelted in a meltdown gasifying zone under supply of carbon carriers and oxygen-containing gas forming a coal fluidized bed, and CO and H.sub.2 containing reduction gas is produced, which is injected into the direct reduction zone and reacted there. For the commercial utilization of low-quality scrap grades, such as, e.g., automotive scrap,(a) scrap is charged into the meltdown gasifying zone in addition to sponge iron,(b) the scrap has an apparent weight of between 300 and 1000 kg/m.sup.3, preferably between 400 and 600 kg/m.sup.3, and(c) the temperature of the coal fluidized bed is maintained at 1,500.degree. to 1,7800.degree. C.

Abstract: A process for melting metal scrap, particularly steel scrap or such high-melting charge material in a shaft furnace operated in cokeless manner by means of fluid fuels is described. The furnace shaft used for carrying out the process is separated from the furnace hearth connected to the bottom thereof by means of a cooled grate arrangement. The burners issue substantially vertically to the longitudinal axis of the shaft into the furnace and the combustion air is recuperatively preheated by means of the shaft furnace waste gases. The amount of heat introduced into the melting unit by means of the burners is subdivided in dosable manner into a component drawn off from the furnace shaft and a component remaining in the furnace hearth. For this purpose the radiating surface of the wall lining in the furnace hearth is between 1.5 and 3.5 m.sup.2, particularly 2 and 2.8 m.sup.2 ton of molten metal produced. The radiation-active, average layer thickness of the gas in the furnace hearth is between 1.5 and 3.

Abstract: This is disclosed a process of recovering molten pig iron or steel pre-products from lumpy iron-oxide containing charging substances. The charging substances are reduced to sponge iron in a direct reduction zone, the sponge iron is smelted in a meltdown gasifying zone under supply of carbon carriers and oxygen-containing gas forming a coal fluidized bed, and CO and H.sub.2 containing reduction gas is produced, which is injected into the direct reduction zone and reacted there. For the commercial utilization of low-quality scrap grades, such as, e.g., automotive scrap,(a) scrap is charged into the meltdown gasifying zone in addition to sponge iron,(b) the scrap has an apparent weight of between 300 and 1000 kg/m.sup.3, preferably between 400 and 600 kg/m.sup.3, and(c) the temperature of the coal fluidized bed is maintained at 1,500.degree. to 1,700.degree. C.

Abstract: Scrap metal for steelmaking in a converter is preheated by a heating installation and subsequently charged into a charging trough. The preheating takes place in a separate furnace which is aligned parallel to the charging trough. The furnace can be brought to an emptying position in such a way that the preheated scrap can fall from the preheating furnace and still retain its orientation.