Convertible metallurgical furnace and modular metallurgical plant comprising said furnace for conducting production processes for the production of metals in the molten state, in particular steel or cast iron

A metallurgical furnace including a vessel with a lower shell for containing a metal bath, the metal bath composed of molten metal and an overlying layer of slag. The lower shell is tiltingly supported and provided with a deslagging opening for evacuating the slag and a tapping opening for tapping the molten metal. The vessel includes an upper shell removably positioned on the lower shell and first and second inlet openings for feeding. The vessel includes a closing roof for the upper closing of the vessel removably positioned on the upper shell and a passage opening for the passage, through the same, of at least one electrode, at least one charge opening for feeding, through the same, charge material in the solid state. At least one of the inlet openings, passage opening, and charge opening is closed or associated with a closing element.