Abstract: In order to effect a reduction and a carburization to form Fe.sub.3 C to the highest possible degree in a relatively short time in an economical process, a treatment in two stages is effected in fluidized beds. The first stage is effected in a circulating fluidized bed system, in which the amount of solids circulated per hour is at least five times the weight of solids contained in the fluidized bed reactor and a major part of the iron content of the charge is pre-reduced. The remaining reduction and the partial or complete conversion to Fe.sub.3 C are effected in the second stage in a conventional fluidized bed. Water is condensed from the exhaust gas from the circulating fluidized bed system and that gas is strengthened by an addition of reducing gases and is reheated to the temperature which is required for the process.

Abstract: Disclosed is a process for the heat treatment of fine-grained iron ore and for the conversion of the heat-treated iron ore to metallic iron, whereina) the fine iron ore is reacted with at least one binder to produce particles having a particle size of >0.1 to 5 mm,b) the particles according to process stage (a) are dried,c) the particles dried according to process stage (b) are heat-treated at a temperature of 700.degree. to 1100.degree. C., andd) the heat-treated particles are reacted to form metallic iron.

Abstract: In order to effect a reduction and a carburization to form Fe.sub.3 C to the highest possible degree in a relatively short time in an economical process, a treatment in two stages is effected in fluidized beds. The first stage is effected in a circulating fluidized bed system, in which the amount of solids circulated per hour is at least five times the weight of solids contained in the fluidized bed reactor and a major part of the iron content of the charge is pre-reduced. The remaining reduction and the partial or complete conversion to Fe.sub.3 C are effected in the second stage in a conventional fluidized bed. Water is condensed from the exhaust gas from the circulating fluidized bed system and that gas is strengthened by an addition of reducing gases and is reheated to the temperature which is required for the process.

Abstract: Residual metallurgical materials which contain zinc and lead are reprocessed by a thermal treatment in a circulating fluidized bed. The required heat is generated in that solid carbon is combusted in the fluidized bed reactor of the circulating fluidized bed. A solid carbon content of 5 to 30% is maintained in the lower part of the fluidized bed. Oxygen-containing gases are supplied to the upper part of the fluidized bed reactor, and CO.sub.2 is formed only in such an amount that zinc metal will not be reoxidized. Substantially all solids are removed from the discharged suspension in a recycle cyclone and are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dustlike compounds of zinc and lead are separated from the gas.

Abstract: In a first fluidized bed vessel containing an expanded fluidized bed, iron oxide-containing materials are reduced under weakly reducing conditions with solid carbonaceous reducing agents to or to less than the FeO state. In a second fluidized bed vessel containing an expanding fluidized bed the gas-solids suspension discharged from the first fluidized bed vessel is treated with a highly reducing fluidizing gas whereby the material is reduced in part to iron metal. From the gas-solid suspension discharged from the second fluidized bed vessel the carbonized carbonaceous material is separated and is recycled to the first fluidized bed vessel. The exhaust gas from which the carbonized carbonaceous material has been removed is purified and CO.sub.2 is removed therefrom and the exhaust gas is subsequently fed as a fluidizing gas to the second fluidized bed vessel.