Abstract: The coke forms are produced in four stages, each constituted by a respective oven chamber, and in which the briquets are, respectively, preheated, dehydrated or dried, carbonized and cooled. Hot gas circuits are provided, in which the hot gas is composed substantially of burnt lean gas of the carbonization, and, for each stage, the hot gases are recirculated in a separate respective circuit. In the preheating, dehydrating and carbonization stages, the hot gases are heated and produced, or supplemented, in a respective separate combustion chamber with the recirculating hot gas in the carbonization stage being supplemented with cooled lean gas from this stage. The recirculating hot gases are dedusted separately in a dust settling chamber in which their flow velocity is reduced to approximately 0.2 to 2.0 m/sec, with the dust being collected.

Abstract: The coke forms are produced in four stages, each constituted by a respective oven chamber, and in which the briquets are, respectively, preheated, dehydrated or dried, carbonized and cooled. Hot gas circuits are provided, in which the hot gas is composed substantially of burnt lean gas of the carbonization, and, for each stage, the hot gases are recirculated in a separate respective circuit. In the preheating, dehydrating and carbonization stages, the hot gases are heated and produced, or supplemented, in a respective separate combustion chamber with the recirculating hot gas in the carbonization stage being supplemented with cooled lean gas from this stage. The recirculating hot gases are dedusted separately in a dust settling chamber in which their flow velocity is reduced to approximately 0.2 to 2.0 m/sec, with the dust being collected.

Abstract: A process for the direct reduction of iron ores using a reducing gas mixture which is passed through a shaft furnace containing the ore to be reduced is disclosed. The process is characterized in that the partial flow of reducing gas mixture is removed from the furnace approximately at the point of transition between the magnetite and Wustite stages of the ore and is regenerated. The regenerated reducing gas is then reapplied to the furnace with a fresh reducing gas mixture resulting in a substantial energy saving.