Abstract: An end product containing iron carbide (Fe3C) is produced from an intermediate product consisting of granular, directly reduced iron. Said intermediate product is supplied by an iron ore reduction plant and is fed to a carburization reactor. Liquid hydrocarbons are conveyed to the carburization reactor at temperatures of 500 to 900° C., at least part of the granular, directly reduced iron being subjected to a swirling movement. The end product removed from the carburization reactor consists of 5 to 90 wt. % Fe3C. A fluidization gas containing methane and hydrogen can be added to the carburization reactor in addition to the hydrocarbons.

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: A zinc- and lead-containing residue from a metallurgical plant is reprocessed by a thermal treatment in a circulating fluidized bed system. A major part of the heat demand is satisfied by a combustion of solid carbonaceous material in the fluidized bed reactor of the circulating fluidized bed system. A reducing fluidizing gas, which is virtually free of free oxygen, is fed to the lower part of the fluidized bed reactor. A solid carbon content of from 5 to 30% is adjusted in the fluidized bed in the lower portion of the fluidized bed reactor, which is supplied in its upper portion with oxygen-containing gases and in which CO.sub.2 is formed only at such a rate that zinc metal is not reoxidized. Substantially all solids are removed in a recycling cyclone from the suspension discharged from the reactor and the removed solids are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dust-like zinc compounds and lead compounds are removed from the gas.