Abstract: When operating mills including a coling plant, a blast furnace arrangement and a converter steelworks, large amounts of partially high-grade so-called cupola gases, such as coke oven gas and converter exhaust gases, form, which cupola gases, so far. In order to render these cupola gases utilizable at a better efficiency, thus reducing the specific energy consumption per ton of crude steel produced, and in order to be less dependent on external scrap, a plant for directly reducing iron ore is additionally adjoined to the mill. The ducts for the exhaust gas from the converters and the coke oven gas ducts from the coking plant are connected to a reformer to produce reducing gas substantially containing CO and H. The reformer is connected with the direct reduction plant via a reducing gas duct.