Smelting assembly for the production of steel

A smelting assembly for production of steel, comprising:

• a single vessel comprised of:
• a fireproof-cladded lower furnace/hearth part with bottom tapping;
• and a substantially cylindrical, water-cooled, upper furnace part,
• wherein the smelting assembly is configured for a running mode without a smelting current as well as for a running mode with a smelting current;
• a first conical furnace cover for the running mode without a smelting current has at least one opening through which at least one top lance for injecting a process gas is introducible into the upper furnace;
• a second conical furnace cover for the running mode with a smelting current has at least one opening through which at least one graphite electrode is introducible into the upper furnace, wherein the first and the second conical furnace covers are placeable onto and removable from the upper furnace part, wherein the smelting assembly is configured so that the running mode is variable by changing between the first and the second furnace covers;
• and
• a plurality of lateral wall injectors arranged spaced in the cylindrical upper furnace part so as to be radially encircling so that the top lance and the lateral wall injectors in an operating position are aligned toward a melt level of a melt which for oxidizing is situated in the lower furnace/hearth part wherein the lateral wall injectors and the top lance are configured so that between 10% and 50% of a gas required for oxidizing is injected through the lateral wall injectors and 50% to 90% of the gas is injected through the top lance into the melt in the smelting assembly, said injections taking place simultaneously and in a mutually adapted manner.