Electrical arc furnace for melting metal material and steel plant comprising said electric arc furnace

Electric arc furnace usable for melting a metal charge comprising both a container having a melting chamber and a plurality of main apertures, which include at least an upper aperture, a lateral outlet aperture to remove the slag that forms on the surface of said molten metal charge, and a lateral feed aperture to feed said metal charge into said melting chamber, and also a cover that can be positioned on said upper aperture to selectively close it, wherein said cover is provided with one or more first secondary apertures into which respective electrodes can be inserted with clearance to melt said metal charge, wherein it also comprises sealing means, at least one of which is associated with at least one of said main apertures, in such a way as to prevent, or limit as much as possible, the unwanted or uncontrolled entry of air coming from the external environment into melting chamber, at least during the process of melting said metal charge.