A refining vessel for high-temperature melt includes a refractory for gas blowing nozzle that includes a central refractory embedded with metal tubules, and an outer refractory circumferentially surrounding the central refractory. The refractory for gas blowing nozzle has a horizontal projection on which a minimum radius of an imaginary circle encompassing all the metal tubules embedded in the central refractory is R (mm), wherein the central refractory has an outline that falls between one circle that is concentric with the imaginary circle and has a radius of R+10 mm, and another circle that is concentric with the imaginary circle and has a radius of R+150 mm. The central refractory is formed of a MgOC refractory having a carbon content of 30 to 80 mass %, and the outer refractory is formed of a MgOC refractory having a carbon content of 10 to 25 mass %.

A shaft of a stirring fan for a heat treatment apparatus includes a blade fixing portion for fixing a plurality of blades. The blade fixing portion has a cylindrical portion extending in a shaft direction of the shaft. A hole inside the cylindrical portion is open to one end face of the shaft. The stirring fan has a discharge portion for discharging gas inside the cylindrical portion to the outside of the blade fixing portion. The discharge portion is open to the outside of the blade fixing portion, at a position away from the one end face of the shaft.

A shaft of a stirring fan for a heat treatment apparatus includes a blade fixing portion for fixing a plurality of blades. The blade fixing portion has a cylindrical portion extending in a shaft direction of the shaft. A hole inside the cylindrical portion is open to one end face of the shaft. The stirring fan has a discharge portion for discharging gas inside the cylindrical portion to the outside of the blade fixing portion. The discharge portion is open to the outside of the blade fixing portion, at a position away from the one end face of the shaft.

A shield for injection lances in metal production furnaces facilitates the adjustment of the contents of the melt in the metal production furnace. The shield has an outer shell joined to an inner shell by a face plate. The outer shell and inner shell define a fluid chamber between them and the face plate has an inlet aperture and an exit aperture for coolant flow through the fluid chamber. The shield is sized and shaped to fit into or around an aperture in the wall of the furnace. The shield has apertures through it to facilitate introduction of additives to the melt in the metal production furnace.

A method of melting an aluminum charge having no more that 4% salt by mass, including during a melting phase, introducing fuel and oxidant via a burner operating at a first firing rate, the fuel and oxidant reacting to form a combustion zone above the aluminum charge, terminating the melting phase and commencing a transition phase when the aluminum charge is nearly completely molten, during the transition phase, reducing the firing rate of the burner to a second firing rate lower than the first firing rate, introducing a non-oxidizing gas at a first velocity to form a non-oxidizing zone between the combustion zone and the aluminum charge, and allowing the aluminum charge to become completely molten, and terminating the transition phase and commencing a tapping phase after the aluminum charge has become completely molten, and during the tapping phase, pouring the molten aluminum charge out of the furnace.

A method of melting an aluminum charge having no more that 4% salt by mass, including during a melting phase, introducing fuel and oxidant via a burner operating at a first firing rate, the fuel and oxidant reacting to form a combustion zone above the aluminum charge, terminating the melting phase and commencing a transition phase when the aluminum charge is nearly completely molten, during the transition phase, reducing the firing rate of the burner to a second firing rate lower than the first firing rate, introducing a non-oxidizing gas at a first velocity to form a non-oxidizing zone between the combustion zone and the aluminum charge, and allowing the aluminum charge to become completely molten, and terminating the transition phase and commencing a tapping phase after the aluminum charge has become completely molten, and during the tapping phase, pouring the molten aluminum charge out of the furnace.

The invention relates to an aluminum scrap melting system (1) comprising a melting furnace (10) comprising a burner (20) which comprises an oxidant injector (23), and a fuel injector (25); a suction hood (30) intended to capture by suction the combustion fumes (F) and comprising a carbon monoxide sensor (37) configured to measure a carbon monoxide concentration (C) in said combustion fumes (F); and a control device (50) configured to receive an item of input information representative of the value of the carbon monoxide concentration (C), and to pilot the oxidant injector (23) and/or the fuel injector (25), according to said item of input information, the oxidant and fuel flows being piloted to contain the volatile organic compound content (VOC) at the output of the melting furnace at concentrations less than a safety value. The invention also relates to a process for melting aluminum scrap with such a melting system (1).

The disclosure discloses a method of operating an electric arc furnace, the method comprising capturing, from at least one facility of a steel mill, a heated metallurgical gas comprising water and carbon monoxide; conducting, by a reactor supply line, said metallurgical gas to a reactor; transforming, by a treatment of said metallurgical gas within said reactor, the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction; and subsequently separating said hydrogen by a separation device. The method is characterized in that it further comprises providing an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melting the iron-bearing material to obtain a molten bath; conducting, by a furnace supply line, said hydrogen to the electric arc furnace, which is arranged downstream of the furnace supply line; and injecting, by a plurality of hydrogen injection devices, said hydrogen into said electric arc furnace, such that said hydrogen reacts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

The disclosure discloses a method of operating an electric arc furnace, the method comprising capturing, from at least one facility of a steel mill, a heated metallurgical gas comprising water and carbon monoxide; conducting, by a reactor supply line, said metallurgical gas to a reactor; transforming, by a treatment of said metallurgical gas within said reactor, the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction; and subsequently separating said hydrogen by a separation device. The method is characterized in that it further comprises providing an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melting the iron-bearing material to obtain a molten bath; conducting, by a furnace supply line, said hydrogen to the electric arc furnace, which is arranged downstream of the furnace supply line; and injecting, by a plurality of hydrogen injection devices, said hydrogen into said electric arc furnace, such that said hydrogen reacts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

An electric furnace has a burner directed toward furnace contents. The burner includes a powder-feeding pipe, a jet hole for jetting a fuel, and a jet hole for jetting combustion-supporting gas. Hydrogen gas or a hydrogen-enriched gaseous fuel is jetted as the fuel to form a burner flame. An auxiliary material is jetted through the powder-feeding pipe so that the auxiliary material passes through an inside of the burner flame. According to a steelmaking method, an electric furnace has a burner that includes a jet hole for jetting a fuel and a jet hole for jetting combustion-supporting gas and that jets a flame through the jet holes toward an inside of the electric furnace. Hydrogen gas or a hydrogen-enriched gaseous fuel is used as the fuel of the burner, and an auxiliary material is blown in to pass through an inside of the flame formed by the burner.