Described are solid agglomerates of fine metal particles and methods for manufacturing same. A liquid oily lubricant is used in the manufacture of the solid agglomerates. The manufacturing comprises blending fine metal particles with the liquid oily lubricant and compacting the oily metallic mixture obtained to desired solid form. Advantageously, the solid agglomerates possess a desirable density, a suitable resistance to crumbling and dusting during handling, and they can resist to high temperature and to humidity. Solid agglomerated metal products, according to the invention, may be useful for different purposes such as quality charge material for steel plants, blast furnaces and foundries.

An apparatus to move and preheat metal material (M) to be fed to a container comprises a containing structure, having an internal compartment and provided with a support wall, a conveyor for the material (M), a fume transit section whose volume reduces as it is distanced from said container along the longitudinal development of said containing structure, and a collector for hot fumes (F) whose volume increases in a manner correlated to said reduction in the fume transit section. The collector is located below said conveyor inside the internal compartment essentially along the entire longitudinal development of said containing structure. Moreover, one or more through apertures are made in said support wall to put the conveyor and the collector into fluidic connection.

Apparatus for continuously conveying and pre-heating a metal charge inside a container of a melting plant, includes at least a channel for conveying the metal charge, at least a hood disposed above the conveyor channel defining a tunnel and/or an expansion chamber, inside which at least part of the fumes exiting from the container advance, and apertures made in cooperation with lateral walls of the conveyor channel to discharge the fumes. The conveyor channel includes an activator that divert the fumes and/or delimit the zone occupied by the metal charge of the conveyor channel, and that cooperate longitudinally with at least part of the conveyor channel.

An apparatus to feed and pre-heat a metal charge to a melting furnace of a steelworks comprises a feeding and pre-heating tower separate from the melting furnace provided with at least one compartment to temporarily contain said metal charge, transfer means to transfer said metal charge to said melting furnace and conveying means to convey the fumes exiting from the melting furnace to said compartment. The apparatus also comprises a post-combustion chamber, disposed adjacent to and below said compartment, and connected on one side to said compartment and on another side to said conveying means, the post-combustion chamber being configured to determine the expansion of the fumes introduced by the conveying means and to direct said expanded fumes toward said compartment along a path such as to determine a desired residence time of said fumes suitable to obtain at least the substantial complete combustion of the unburned gases present in said fumes.

A process for producing clean steel products with low nitrogen content, below 35 ppm, in a steelmaking plant comprising a direct reduced iron (DRI) source, which may be a direct reduction plant or a DRI storage facility, an electric arc furnace (EAF), a vacuum degassing system (DS), and a continuous casting system (CC) is disclosed. The process comprises a first stage of melting and refining a metallic iron charge, a second stage of tapping molten steel from the electric arc furnace (EAF) into a ladle, a third stage of exposing molten steel to a pressure below the atmospheric pressure and a fourth stage of casting molten steel to clean steel products. Optionally, the molten steel tapped from the EAF is treated in a ladle furnace (LF) prior to being treated in the degassing system (DS). The metallic iron charge fed to the EAF comprises more than 70% by weight of DRI in the form of pellets or briquettes having a carbon content above 2.5 weight %. Preferably, the metallic iron charge is fed to the EAF at a temperature of 400 C. or higher. The low nitrogen level in the steel products made according to the Application is achieved by forming a first foamy slag in said first process stage and is maintained in a foamy state by controlling the feed of fluxes, oxygen, and carbonaceous materials to the EAF and by forming a second slag, after molten steel is tapped from the EAF, having a predetermined composition capable of continuing the desulfurization and providing a thermal and chemical insulation to prevent nitrogen pickup and promote nitrogen removal of molten steel. The process also comprises carrying out one or more of the following actions: (a) controlling the concentration of nitrogen and sulfur in the raw materials at each process stage, (b) promoting nitrogen removal from steel, (c) decreasing the time spent by the molten steel at each process stage and between each and subsequent process stages, and (d) preventing nitrogen pickup by the molten steel all along said process stages. Steel products made according to the Application comprise the following elements expressed in weight %: C0.05%, Si4.5%, Al2.0%; Mn2.0%; P0.20%; Ni0.200%, Cu0.200%; N0.0030%, Ni0.200%, S0.0035%.

A method for recycling processing of dust generated in a converter furnace, includes: crushing and drying a cake formed by adding a binder to a slurry containing iron powder-containing dust that is generated at the time of converter blowing and wet-collected to produce a mixed slurry and subjecting the produced mixed slurry to a dehydration treatment in a filter press; accumulating the cake in an accumulation tank; and charging the cake into a converter furnace 10, the crushed product in the accumulation tank 25 is kept at a temperature of less than 90 C. by forcibly passing air into the accumulation tank 25 and charged into a converter furnace according to the converter operation.

An apparatus for manufacturing molten metal has a stationary electric furnace, a raw material charging chute, and exhaust duct and a secondary combustion burner in the furnace top, and a shock generator. The raw material charging chute is in one end of the furnace in a width direction and an electric heating region is spaced from the raw material charging chute in the width direction. A raw material layer having a sloping surface extends downward from the one end of the furnace having the raw material charging chute toward the electric heating region, the sloping surface supporting a metal agglomerate raw material layer. The shock generator is provided at least partially within the raw material and extends to the sloping surface, to be in contact with the metal agglomerate raw material layer, and to mechanically overcome hanging of the metal agglomerate raw material layer on the sloping surface.

A method of starting a molten-bath based melting process includes commencing supplying cold oxygen-containing gas and cold carbonaceous material into a main chamber of a smelting vessel within at most 3 hours after completing a hot metal charge into the vessel and igniting the carbonaceous material and heating the main chamber and molten metal in the main chamber.

A process for producing clean steel products with low nitrogen content, below 35 ppm, in a steelmaking plant comprising a direct reduced iron (DRI) source, which may be a direct reduction plant or a DRI storage facility, an electric arc furnace (EAF), a vacuum degassing system (DS), and a continuous casting system (CC) is disclosed. The process comprises a first stage of melting and refining a metallic iron charge, a second stage of tapping molten steel from the electric arc furnace (EAF) into a ladle, a third stage of exposing molten steel to a pressure below the atmospheric pressure and a fourth stage of casting molten steel to clean steel products. Optionally, the molten steel tapped from the EAF is treated in a ladle furnace (LF) prior to being treated in the degassing system (DS). The metallic iron charge fed to the EAF comprises more than 70% by weight of DRI in the form of pellets or briquettes having a carbon content above 2.5 weight %. Preferably, the metallic iron charge is fed to the EAF at a temperature of 400 C. or higher. The low nitrogen level in the steel products made according to the Application is achieved by forming a first foamy slag in said first process stage and is maintained in a foamy state by controlling the feed of fluxes, oxygen, and carbonaceous materials to the EAF and by forming a second slag, after molten steel is tapped from the EAF, having a predetermined composition capable of continuing the desulfurization and providing a thermal and chemical insulation to prevent nitrogen pickup and promote nitrogen removal of molten steel. The process also comprises carrying out one or more of the following actions: (a) controlling the concentration of nitrogen and sulfur in the raw materials at each process stage, (b) promoting nitrogen removal from steel, (c) decreasing the time spent by the molten steel at each process stage and between each and subsequent process stages, and (d) preventing nitrogen pickup by the molten steel all along said process stages. Steel products made according to the Application comprise the following elements expressed in weight %: C0.05%, Si4.5%, Al2.0%; Mn2.0%; P0.20%; Ni0.200%, Cu0.200%; N0.0030%, Ni0.200%, S0.0035%.

Molten iron is produced in an electric furnace with high energy utilization efficiency at a low cost. In an electric furnace in which a shaft-type preheating chamber is provided on and continuously with a melting chamber and used to preheat iron scrap, an exhaust gas generated in the melting chamber is passed through the preheating chamber filled with the iron scrap so as to preheat the iron scrap, the iron scrap thus preheated is sequentially caused to descend in the preheating chamber so as to be supplied into the melting chamber, and the iron scrap is melted in the melting chamber to obtain molten iron m.