Abstract: A process and a plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with a horizontal conveyor, wherein the metal charge is hit, in countercurrent, by the exhaust fumes or gas leaving the electric melting furnace and by jets of gas ejected through a plurality of nozzles positioned on the hood of the tunnel. The nozzles are arranged in groups interspaced from each other in a longitudinal direction with respect to the tunnel, and generate a small-scale turbulence or inject small fast gas jets that can penetrate the main gas stream passing through the preheating tunnel, and simultaneously generate a “horseshoe vortex” structure composed of a descending central gas flow (“downwash”), and ascending flows (“upwash”) close to the side walls of the preheating tunnel, which enable a desired circulation of the gases.

Abstract: A process and a plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with a horizontal conveyor, wherein the metal charge is hit, in countercurrent, by the exhaust fumes or gas leaving the electric melting furnace and by jets of gas ejected through a plurality of nozzles positioned on the hood of the tunnel. The nozzles are arranged in groups interspaced from each other in a longitudinal direction with respect to the tunnel, and generate a small-scale turbulence or inject small fast gas jets that can penetrate the main gas stream passing through the preheating tunnel, and simultaneously generate a “horseshoe vortex” structure composed of a descending central gas flow (“downwash”), and ascending flows (“upwash”) close to the side walls of the preheating tunnel, which enable a desired circulation of the gases.

Abstract: A process and plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with side walls, a vault and a horizontal conveyor, wherein the metal charge is enveloped in countercurrent by fumes or exhaust gases exiting from the electric melting furnace, includes causing an air intake from the surrounding environment through openings along the preheating tunnel to complete the combustion of the fumes or exhaust gases. The intake is regulated by acting on suction fans and/or on the openings, based on measurements by temperature sensors and/or the composition of the outgoing gases in or downstream of the terminal part of the tunnel. The metal charge is enveloped by jets of gas ejected through a plurality of nozzles arranged non-uniformly longitudinally on the vault of the tunnel, with a greater concentration on the top of the vault of the tunnel.

Abstract: A method for the production of cast iron starting from pre-reduced iron ore (DRI) with an electric arc furnace includes the steps of preparing a charge of pre-reduced iron ore DRI having a metallization higher than 90% and containing over 2.8% by weight of carbon, wherein at least 80% of the carbon is combined with the iron to form iron carbide Fe3C; charging the charge of pre-reduced iron ore into the electric arc furnace; and melting the DRI charge to form liquid cast iron having at least 80% by weight of actual carbon content deriving from the carbon in the charge of pre-reduced iron ore, the melting step being in a reducing atmosphere and in a melting chamber of the electric arc furnace subjected to a positive internal pressure generated by the gases produced by reduction reactions that develop during melting.

Abstract: 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.

Abstract: A process and a plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with a horizontal conveyor, wherein the metal charge is hit, in countercurrent, by the exhaust fumes or gas leaving the electric melting furnace and by jets of gas ejected through a plurality of nozzles positioned on the hood of the tunnel. The nozzles are arranged in groups interspaced from each other in a longitudinal direction with respect to the tunnel, and generate a small-scale turbulence or inject small fast gas jets that can penetrate the main gas stream passing through the preheating tunnel, and simultaneously generate a “horseshoe vortex” structure composed of a descending central gas flow (“downwash”), and ascending flows (“upwash”) close to the side walls of the preheating tunnel, which enable a desidered circulation of the gases.

Abstract: A method for the production of cast iron starting from pre-reduced iron ore (DRI) with an electric arc furnace includes the steps of preparing a charge of pre-reduced iron ore DRI having a metallization higher than 90% and containing over 2.8% by weight of carbon, wherein at least 80% of the carbon is combined with the iron to form iron carbide Fe3C; charging the charge of pre-reduced iron ore into the electric arc furnace; and melting the DRI charge to form liquid cast iron having at least 80% by weight of actual carbon content deriving from the carbon in the charge of pre-reduced iron ore, the melting step being in a reducing atmosphere and in a melting chamber of the electric arc furnace subjected to a positive internal pressure generated by the gases produced by reduction reactions that develop during melting.

Abstract: A method for the production of cast iron starting from pre-reduced iron ore (DRI) with an electric arc furnace includes the steps of preparing a charge of pre-reduced iron ore DRI having a metallization higher than 90% and containing over 2.8% by weight of carbon, wherein at least 80% of the carbon is combined with the iron to form iron carbide Fe3C; charging the charge of pre-reduced iron ore into the electric arc furnace; and melting the DRI charge to form liquid cast iron having at least 80% by weight of actual carbon content deriving from the carbon in the charge of pre-reduced iron ore, the melting step being in a reducing atmosphere and in a melting chamber of the electric arc furnace subjected to a positive internal pressure generated by the gases produced by reduction reactions that develop during melting.

Abstract: A metallurgical furnace including a vessel, in turn having a lower shell for containing the metal bath, the metal bath being composed of molten metal and an overlying layer of slag, wherein the lower shell is tiltingly supported and is provided with a deslagging opening for evacuating the slag and with a tapping opening for tapping the molten metal, and an upper shell removably positioned on the lower shell and provided with at least one inlet opening for feeding, through the same, charge material in the solid state or in the molten state, a closing roof for the upper closing of the vessel, wherein the closing roof is removably positioned on the upper shell and is provided with a passage opening for the passage, through the same, of at least one electrode and at least one charge opening for feeding, through the same, charge material in the solid state, wherein at least one of the inlet openings, the passage opening, the charge opening is closed or can be associated with a closing element of the removable type

Abstract: A method for the production of cast iron starting from pre-reduced iron ore (DRI) with an electric arc furnace includes the steps of preparing a charge of pre-reduced iron ore DRI having a metallization higher than 90% and containing over 2.8% by weight of carbon, wherein at least 80% of the carbon is combined with the iron to form iron carbide Fe3C; charging the charge of pre-reduced iron ore into the electric arc furnace; and melting the DRI charge to form liquid cast iron having at least 80% by weight of actual carbon content deriving from the carbon in the charge of pre-reduced iron ore, the melting step being in a reducing atmosphere and in a melting chamber of the electric arc furnace subjected to a positive internal pressure generated by the gases produced by reduction reactions that develop during melting.

Abstract: A process for heating a metal feedstock (31) fed in continuous to a smelting furnace (30) through a second horizontal heating section (34) through which hot discharge fumes collected from said furnace (30) pass, said fumes exerting a heating phase of said feedstock (31), characterized in that, immediately before entering said second heating section (34), the feedstock (31) is subjected to a preheating phase by heating means other than the discharge fumes collected from the smelting furnace (30). In a plant for the embodiment of said process, said different heating means are envisaged inside a first preheating section (33), which is operatively connected with said second heating section (34) by means of an intermediate fume evacuation section (35), the fumes coming from said sections (33) and (34) being conveyed to said section. Said sections (33, 34) preferably have a tunnel configuration.

Abstract: A plant and relative process for continuously feeding heated metallic material to a melting furnace, according to which, on at least one feeding line defined by a conveyor for continuously advancing the material to the furnace, there is one pair of operative modules defined by a first and a second operative feeding and heating module, the first and second operative modules being positioned in succession with respect to each other along the line, the first module being suitable for forming and directly heating a first layer of the material arranged on the line, and the second module being suitable for forming and directly heating a second layer of the material arranged superimposed with respect to the first layer.

Abstract: A process for heating a metal feedstock (31) fed in continuous to a smelting furnace (30) through a second horizontal heating section (34) through which hot discharge fumes collected from said furnace (30) pass, said fumes exerting a heating phase of said feedstock (31), characterized in that, immediately before entering said second heating section (34), the feedstock (31) is subjected to a preheating phase by heating means other than the discharge fumes collected from the smelting furnace (30). In a plant for the embodiment of said process, said different heating means are envisaged inside a first preheating section (33), which is operatively connected with said second heating section (34) by means of an intermediate fume evacuation section (35), the fumes coming from said sections (33) and (34) being conveyed to said section. Said sections (33, 34) preferably have a tunnel configuration.