A method for operating an electric arc furnace having at least one electrode, the method including the following steps: introducing material that is to be melted in the form of an actual mass flow into the electric arc furnace and feeding electrical energy via at least one electrode into the electric arc furnace in order to melt the introduced material depending on a previously determined, necessary electrical energy input. The necessary electrical energy input into the arc furnace is determined depending on the mass flow input into the furnace.

The invention is directed to a process for extracting a metal from a slag containing said metal, wherein the liquefied metal-containing slag is heated in at least one electric arc furnace (1, 2). In order provide an improved method for recovering especially copper from slags, the invention provides that the metal-containing slag is heated in a first furnace (1) constructed as an AC electric furnace or a DC electric furnace, and the melt is introduced from the first furnace (1) into a second furnace (2) which is constructed as a DC electric furnace. Further, the invention is directed to an arrangement for extracting a metal from a slag containing said metal.

Sensors measure magnetic field components, and the measured fields are used to calculate and estimated transverse position of a longitudinal electric current flowing as an electric discharge across a discharge gap. Based on the estimated position, and according to a selected transverse trajectory or distribution of the estimated discharge position, magnetic fields are applied transversely across the discharge gap so as to control or alter the estimated discharge position. Inventive apparatus and methods can be employed, inter alia, during operation of a vacuum arc furnace.

An electrode clamping device is suitable for use in an electrical arc furnace. The clamping device is used releasably to clamp an electrode of an electric arc furnace, and includes at least one elongate tension element configured in use to extend at least partially about a periphery of the electrode of the arc furnace in order for the tension element to define a tensionable loop about the electrode that is adapted to exert a clamping force on the electrode when tensioned. The clamping device also includes a tensioning mechanism including tensioning means adapted to exert a tensile force on end zones of the clamping element so as to tension the tension element, characterized in that the force exerted by the tensioning means is directed in a radial direction relative to the electrode.

A melting and holding furnace includes a main body and a material input mechanism supplying a molten metal to the body which includes a melting chamber; a molten metal receiving chamber; a pumping-out chamber; and a molten metal heating mechanism. The input mechanism includes a molten-metal surface level sensor to detect that the surface height position of the metal in the pumping-out chamber has reached a lower limit that is set to be above the lower surface height position of a lid of the melting chamber, and is set to supply the receiving chamber with the metal and/or the metal block when the sensor detects that the surface height position of the metal in the pumping-out chamber has reached the lower limit so that the surface height position of the metal in the pumping-out chamber is always kept above the lower surface height position of the lid.

A consumable electrode vacuum arc furnace and, more particularly, a direct current consumable electrode vacuum arc furnace is provided, wherein no water cooling is needed to cool down typically neither the electrodes, nor any other parts of the furnace, and this includes the shell, the flanges ports and the electrical connections of the furnace. The present furnace uses non-metallic electrodes, such as graphite electrode, which are suitable for melting metals, smelting of metal ores, and metal oxide to elemental metal where the use of graphite electrodes is a common practice. The present furnace and electrode assemblies render possible to perform a true continuous process of melting and smelting under controlled pressure.

A self-baking electrode includes a cylindrical shroud having a longitudinal central axis A. The shroud is made of an electrically-conductive material and disposed vertically on top of a vat of the furnace over one length of the self-baking electrode. The electrode includes a central column disposed within the shroud, substantially aligned on the longitudinal axis A. The central column is suspended from a device independent of the shroud such that the central column is adapted to slip in vertical translation within the shroud and a crude carbonaceous paste disposed around the central column in a top portion of the shroud. The paste is softened and baked under an effect of heat into a stiff carbonaceous paste sticking to the central column in a bottom portion of the shroud. The central column includes a series of electrically-conductive carbonaceous elongate elements. The carbonaceous elongate elements are flexible.

A DC plasma arc furnace, a method of co-processing waste and metal, a method of producing energy by processing material using the furnace, and the products produced by the furnace are provided. Metal may be efficiently processed by the furnace via an increased organic content in other feedstock fed into the furnace.

A sealing system for isolating the environment inside a vitrification container from the outside environment comprises a vitrification container with a lid. The lid comprises two or more electrode seal assemblies through which two or more electrodes may be operatively positioned and extend down through the lid into the vitrification container. The electrodes may move axially up and down through the electrode seal assemblies or lock into place. The electrode seal assemblies each comprise a housing having two halves with recessed ring grooves. Sealing rings with a split may be placed into the grooves. Gas galleries may be machined or cast into the housing such that they are adjacent to the ring grooves. The gas galleries distribute gas onto the external faces of the sealing rings causing a change in pressure resulting in the sealing rings compressing onto the electrodes and forming a seal.

Melting furnace (1), in particular for the production of metal alloys by melting alloying constituents, with a melting crucible (10), a cylindrical electrode rod (40) with a consumable electrode (41) attached thereto and a power supply (50) that is configured to supply the electrode (41) with power via the electrode rod (40), wherein the electrode rod (40) can be rotated about its own axis and moved along its own axis during the melting process.