A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle Θ from 30° to 60° connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

A furnace assembly for a metal-making process, including: an electric arc furnace configured for flat bath operation and having a bottom, and an electromagnetic stirrer configured to be arranged underneath the bottom of the electric arc furnace to enable stirring of molten metal in the electric arc furnace.

Gas purging system comprising a gas purging plug (10) and gas purging plug (10) for metallurgic applications and a gas supply pipe (30) connected to the gas purging plug (10), the gas purging plug (10) with a ceramic refractory body (10k) with a first end (10u) and a second end (100); the second end (100) is in the mounted position of the gas purging plug (10) in contact with a metal melt (41); the first end (10u) is at least partially covered with a metal cover (12.1), the metal cover (12.1) comprises an opening (16) to which optionally a gas supply adapter (20) is connected; the gas purging plug (10) is designed in such a way, that a purging gas which is supplied via the gas supply pipe (30) to the opening (16) flows through the body (10k) and exits the body (10k) at the second end (100); and wherein at least one electronic sensor (70, 70.1, 70.2, 70.3, 70.4) is in contact with the gas purging plug (10), to detect an oscillation waveform of a mechanical vibration (81). The gas purging system further comprises a data processing unit (80) for acquiring the oscillation waveform of a mechanical vibration (81) detected by the electronic sensor (70, 70.1, 70.2, 70.3, 70.4) of the gas purging plug (10) and for calculating a bubble index-signal (83) from the oscillation waveform of a mechanical vibration (81) detected; a control unit (100); wherein the control unit (100) is configured to: displaying the bubble index-signal (83) and/or varying the volume flow (102) through the gas supply pipe (30) depending on the bubble index signal (83) and/or -generating a warning signal (101) when the bubble index signal (83) lies outside a defined range.

A furnace assembly for a metal-making process, including: an electric arc furnace configured for flat bath operation and having a bottom, and an electromagnetic stirrer configured to be arranged underneath the bottom of the electric arc furnace to enable stirring of molten metal in the electric arc furnace.

A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle from 15 to 35 connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

A process and an apparatus are disclosed for improved recovery of metal from hot and cold dross, wherein a dross-treating furnace is provided with a filling material with good capacity to store heat. This filling material is preheated to a desired temperature by injection of an oxidizing gas to burn non-recoverable metal remaining in the filling material after tapping of the recoverable metal contained in the dross and discharging of the treatment residue. When dross is treated in such furnace, the heat emanating by conduction from the filling material is sufficient to melt and separate the recoverable metal contained in the dross, without addition of an external heat source, such as fuel or gas burners, plasma torches or electric arcs and without use of any salt fluxes. Furthermore, the recovered metal being in the molten state can be fed to the molten metal holding furnace without cooling the melt; in addition, the non-use of fluxing salt for the treatment means that the non-contaminated residue can be used as a cover for the electrolytic cells in the case of aluminum. In the case of zinc dross, the residue is a valuable zinc oxide by-product very low in contaminants.

A furnace assembly for a metal-making process, including: an electric arc furnace configured for flat bath operation and having a bottom, and an electromagnetic stirrer configured to be arranged underneath the bottom of the electric arc furnace to enable stirring of molten metal in the electric arc furnace.

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 %.

To improve the position of a cylindrical ceramic hollow body the invention relates to a securing device for use with a gas purging brick, where the securing device has the following characteristics in its operational position: A base body which, with its bottom and a circumferential wall, defines a cylindrical space with a corresponding central longitudinal axis, the bottom features an opening whose longitudinal axis aligns with the central longitudinal axis the bottom features a ring-shaped channel which extends concentrically around the opening. at least an inner wall of the channel which is adjacent to the opening consists of a material which is plastically ductile under the application of pressure, a ring-shaped compact whose radial wall cross-section increases in size upwards from a lower free end, so that the inner wall of the channel deforms plastically, thereby reducing the cross section of the opening, after the compact is pressed into the channel.

A method of providing an inerting atmosphere to the surface of molten aluminum in a vortex charge well of a reverberatory melting furnace is provided. The purpose is to improve aluminum recovery (reduce aluminum oxidation melt loss) by displacing the ambient atmosphere above the molten vortex with an inert gas. The method includes introducing a flow of an inerting gas into an inerting region immediately above the surface of the vortex charge well. The inerting gas may be selected from the group consisting of nitrogen, argon, or a mixture thereof. The inerting gas may be introduced into the charge inlet chute, through a diffuser, or a ring manifold. The vortex charge well may include a lid.