Process and apparatus for making molten steel

Process for making molten steel comprising the steps of:

• a) melting preheated solid iron sources and preheated lumps of solid carbon sources loaded into a melting vessel with heat generated by an electric arc to form a carbon-containing molten material having a surface and containing 0.3 to 2.0% by weight carbon and to form an electric arc-generated exhaust gas;
• b) melting additional preheated solid iron sources and additional preheated lumps of solid carbon sources loaded into the carbon-containing molten material in the melting vessel with heat generated by a combustion reaction, said combustion reaction being performed by feeding oxygen into the molten material during said reacting through nozzles, said nozzles being arranged in the melting vessel below the surface of the molten material, to form a refined molten material having a carbon content below 0.4% by weight and to form a combustion exhaust gas;
• c) feeding an oxygen-containing gas into the melting vessel above the surface of the molten material during said feeding of said oxygen into the molten material in step b);
• and
• d) preheating solid iron sources with said electric arc-generated exhaust gas formed during said step a) and with said combustion exhaust gas formed during step b) in said melting vessel to form the preheated solid iron sources.