Abstract: An improved apparatus for producing steel, including a lower furnace, an annular, water-cooled, fireproof lined cylindrical upper furnace, on which an upwardly closing conically tapering hat having openings can be placed. The smelting assembly is configured for the operational mode without melt flow and the operational mode with melt flow. To this end, at least one opening is provided in the conical furnace cover, through which opening at least one top lance can be introduced into the upper furnace. A plurality of sidewall injectors radially rotate around the cylindrical upper furnace in such a way that in a working position, the top lance and the sidewall injectors are directed onto a smelt level of a molten mass located in the lower furnace for refining.

Abstract: A melting apparatus for steel production includes a support structure to support a shell for the production and tapping of steel, and a source or zone for the emission of fumes resulting from the tapping of the steel from the shell. The melting apparatus also includes a tapping hood integrated into the support structure and provided with a suction mouth positioned directly above the zone for the emission of fumes, the shell is provided with a bottom wall in which an E.B.T. is provided for tapping the steel.

Abstract: Disclosed herein is a roof for an electric furnace. The roof includes: a small-ceiling seating port (120) which has a small-ceiling seating surface (122) and a small-ceiling support surface (124) that extends from the small-ceiling seating surface inwards and downwards; and a large ceiling (130) which has an upper roof panel (132) that radially extends from the small-ceiling seating port at a downward inclination angle, a lower roof panel (134) disposed below the upper roof panel at a position spaced apart from the upper roof panel, and a side roof panel (136) connected to the upper roof panel and the lower roof panel. The upper roof panel is connected to the outer circumferential surface of the small-ceiling seating port, and the lower roof panel is connected to a lower end of the small-ceiling support surface so that the inclination angle of the lower roof panel can be increased.

Abstract: A furnace damper control system including a furnace having at least one opening through which electromagnetic radiation from within the furnace may be sensed, an exhaust duct capable of receiving an exhaust gas stream emerging from the furnace, and a controllable damper capable of adjusting the pressure in the exhaust duct. A sensor is capable of sensing electromagnetic radiation through one or more of the openings of the furnace and generating a sensor signal corresponding to the electromagnetic radiation, and a processor is capable of processing the sensor signal and generating a monitoring signal responsive to a parameter of the electromagnetic radiation indicative of furnace emissions. A controller is capable of controlling the damper responsive to the monitoring signal indicative of the furnace emissions.

Abstract: Iron production furnace equipment includes a melting reactor into which iron oxide-containing raw material and slag formers are added. A melter arrangement melts the iron oxide-containing raw material and transforms the melted raw material into liquid slag. A smelting reduction reactor is connected to the melting reactor by a slag transfer arrangement. The smelting reduction reactor includes a heater arrangement for heating the slag, a port for supplying a reductant for reducing the iron oxide in the slag into a liquid iron melt and produces a combustible gas mixture including at least one of CO and H2. A gas connection is provided between the smelting reduction reactor and the melter arrangement. The melter arrangement in turn comprises a combuster combusting the gas mixture for purpose of melting the raw material.

Abstract: Provided is a method in which, when discarded batteries such as lithium-ion batteries are treated by a dry process, slag having a reduced viscosity is obtained to heighten the recovery of valuable metals. The method for recovering valuable metals includes a dry process (S20) which includes a melting step (ST21), a slag separation step (ST22), and an alloy separation step (ST23), the slag having an aluminum oxide content of 5 mass % or higher but less than 20 mass % and an iron content in terms of metallic iron amount of 20-40 mass %. Furthermore, silicon oxide and calcium oxide are added as a flux in the melting step (ST21) so that the slag has a melting point of 1,400° C. or lower, and the melting step (ST21) is conducted at 1,400° C. or lower. Thus the recovery of the alloys can be heightened.

Abstract: The present invention provides a shaft high temperature continuous graphitizing furnace comprising a furnace body comprising a feeding inlet and a discharging outlet, an electrode pair, a cooling system and a discharging device; the furnace body is designed to be a shaft cylindrical structure; the electrode pair is provided within the furnace body and comprise an upper electrode and a lower electrode, the upper electrode is located below the feeding inlet, and an umbrella or cone table shape electric field having a lower cross section area greater than its upper cross section area arises between the upper electrode and eh lower electrode; and the cooling system is located between the lower electrode and the discharging outlet.

Abstract: A furnace damper control system including a furnace having at least one opening through which electromagnetic radiation from within the furnace may be sensed, an exhaust duct capable of receiving an exhaust gas stream emerging from the furnace, and a controllable damper capable of adjusting the pressure in the exhaust duct. A sensor is capable of sensing electromagnetic radiation through one or more of the openings of the furnace and generating a sensor signal corresponding to the electromagnetic radiation, and a processor is capable of processing the sensor signal and generating a monitoring signal responsive to a parameter of the electromagnetic radiation indicative of furnace emissions. A controller is capable of controlling the damper responsive to the monitoring signal indicative of the furnace emissions.

Abstract: A furnace damper control system and method thereof including a furnace having at least one opening through which electromagnetic radiation from within the furnace may be sensed, an exhaust duct capable of receiving an exhaust gas stream emerging from the furnace, and a controllable damper capable of adjusting the pressure in the exhaust duct. A sensor is capable of sensing electromagnetic radiation through one or more of the openings of the furnace and generating a sensor signal corresponding to the electromagnetic radiation, and a processor is capable of processing the sensor signal and generating a monitoring signal responsive to a parameter of the electromagnetic radiation indicative of furnace emissions. A controller is capable of controlling the damper responsive to the monitoring signal indicative of the furnace emissions.

Abstract: A vitreous silica crucible manufacturing apparatus includes a plurality of carbon electrodes configured to heat and melt raw material powder by arc discharge, and a value of a ratio R2/R1 of a diameter R2 of a front end of each of the carbon electrodes to a diameter R1 of a base end is set in a range of 0.6 to 0.8. Each carbon electrode has a diameter reduction portion formed at a front end position and reduced in diameter from a diameter R3 of a base end side to the diameter R2 of the front end. When a length of the diameter reduction portion is L1, the diameter of the front end is R2, the diameter of the base end is R1, an angle between the axis lines of the carbon electrodes is ?1, and X=(R1?R2)/2, a value of L1?(X/tan(?1/2)) is set in a range of 50 to 150 mm.

Abstract: A furnace damper control system and method thereof including a furnace having at least one opening through which electromagnetic radiation from within the furnace may be sensed, an exhaust duct capable of receiving an exhaust gas stream emerging from the furnace, and a controllable damper capable of adjusting the pressure in the exhaust duct. A sensor is capable of sensing electromagnetic radiation through one or more of the openings of the furnace and generating a sensor signal corresponding to the electromagnetic radiation, and a processor is capable of processing the sensor signal and generating a monitoring signal responsive to a parameter of the electromagnetic radiation indicative of furnace emissions. A controller is capable of controlling the damper responsive to the monitoring signal indicative of the furnace emissions.

Abstract: A device that prevents exhaust gas leakage during movement of an electrode in an electric furnace. An electrode holder is attached to the electrode. An actuator moves the electrode between first and second positions within an aperture formed in an upper portion of the furnace. A fixed section is attached to a waste charging station. A first moving section is moveably coupled with the fixed section, a second moving section is moveably coupled with the first section and fixedly attached to the electrode holder on a first side, and a third moving section is fixedly attached to the electrode holder on a second side opposite the first side. The device moves between a retracted position in which the first and second moving sections are adjacent to the fixed member, and an extended position in which the first and second moving sections are distal from the fixed member.

Abstract: A method and apparatus for melting vitrifiable materials employs a melting tank for containing a molten bath with an upper surface. The tank has a floor and side walls and channels for discharging molten materials. A crown is situated above the floor and vitrifiable materials are introduced onto the upper surface of the molten bath. A plurality of electrodes having a selected shape and position are situated inside the tank for melting the vitrifiable materials with electric current. The electrodes rest on the floor and extend across the furnace to the opposite wall so as to reduce the head of the molten bath and consequently reduce melting time and energy consumption.

Abstract: A fume extraction system includes a combustion zone coupled with an exhaust outlet of a furnace to receive an exhaust gas stream emerging from the furnace outlet during system operation, where the exhaust gas stream includes explosive gases that undergo combustion reactions within the combustion zone. A duct section is aligned downstream from the combustion zone to deliver the exhaust gas stream toward a venting outlet. A suction unit establishes a negative pressure within the system so as to draw the exhaust gas stream from the furnace outlet and through the fume extraction system during system operation. An exhaust damper is further provided within the system between the combustion zone inlet and the suction unit. A control system selectively controls the negative pressure applied to the furnace, combustion zone and duct section based upon a measured concentration of at least one gas constituent within the exhaust gas stream.

Abstract: A method of operating an induction furnace so as to receive electric arc furnace (EAF) dust, basic oxygen furnace (BOF) sludge/dust and/or other iron and volatile metals containing materials as a feed stream on a batch, continuous or semi-continuous basis together with a iron-containing material feed, and therefrom produce an iron-containing hot metal or pig iron product while recovering iron value from the feed materials and recovering volatile metal components contained in the feed materials.

Abstract: An arc furnace that utilizes a combined DC arc system and an AC joule heating system to melt the waste disposed therein and to keep the waste material in a molten condition. The DC arc system utilizes the AC joule heating electrodes as part of the DC current path, thereby eliminating the need for a counter DC electrode. Furthermore, the AC joule heating system provides for peripheral and radial AC current flow to neighboring AC joule heating electrodes, thereby creating a stirring effect in the molten waste. This design greatly simplifies the arc furnace control system while providing a more effective thermal control of the molten waste.

Abstract: Device to take in fumes and cool the roof (10) of electric furnaces. The device has a central aperture (11) into which an electrode can be inserted and a peripheral aperture (12) to take in and discharge the fumes. The device also has a first cooling system (13) for a central zone surrounding, and cooperating with, the central aperture (11), and a second system (15) to take in and convey the fumes. The first cooling system (13) includes a circular cyclone chamber (18) having a plurality of turns (19) able to cool the zone surrounding the central aperture (11).

Abstract: A direct-current arc furnace for producing steel has a smelting vessel with electrodes, tapping openings for the molten mass and slag, and a device for a direct removal of exhaust gases. The smelting vessel is extended upwardly by a central shaft for introducing melt-down material into the vessel. The extension of the central shaft forms a melt-down material column. A shaft suction device is provided as an extension of the shaft for removal of the exhaust gases during the smelting process. Adjacent to the shaft openings are provided in the upper part of the smelting vessel for receiving a vessel suction device for dust and/or gases resulting during the charging process of the melt-down material. The shaft suction device and the vessel suction device are connected to a common device and switching elements are provided for actuating only one suction device and/or adjusting a combination of the exhaust gas flows dependent on the charging and smelting process.

Abstract: An apparatus and method for processing liquid slag and baghouse dust from a steelmaking furnace such as an EAF to recover valuable metals from the slag and dust includes a treatment vessel having a movable lower shell portion for receiving liquid slag and an upper shell portion that couples with the movable lower shell portion during heat activation of the treatment vessel. The slag is combined with silicon dioxide, a reducing agent, baghouse dust, and an inert gas before being heated to between approximately 1400° C. and 3000° C. The heat treatment results in a molten reduced iron and manganese metallic material, a treated slag layer, and an off-gas containing lead, zinc, and carbon monoxide. The off-gas is combusted, cooled, and solidified, resulting in lead oxide and zinc oxide. The slag layer is tapped, cooled, and solidified. The metallic layer is tapped for recycle in the steel making process.

Abstract: A process for making steel in an electric arc furnace includes providing a molten charge which is a melt composed of a high carbon ferrous metal in the electric arc furnace by one of preparing the melt in the furnace or introducing the melt into the furnace, the high carbon ferrous metal being composed of less than 3% carbon, less than 0.2% silicon, and less than 0.2% manganese, and the melt having a temperature of at least 1375° C.; adding to the molten charge provided in the furnace a solid metallic charge composed of least one material selected from the group consisting of scrap steel, hot briquetted iron, direct reduced iron, and iron ore to provide a charge mixture; refining the charge mixture by melting in the absence of gaseous oxygen to provide a molten steel; and superheating, finishing and tapping the molten steel into a ladle for subsequent casting thereof.

Abstract: A roof (3) for a metallurgical ladle/furnace (L.A.F) (1) comprising a self-supporting structure of metallic pipework (4) defining at least one flow circuit for cooling water, with a lower end having a circular peripheral flange (A), with a cylindrical body member (c) of smaller diameter than the flange (A) located above the flange (A) (in use away from the ladle/furnace), and is provided with an end wall (14) having a plurality of apertures (14) each to receive, in a gas-tight manner, a carbon electrode (8), and an aperture (5) for fume extraction provided in the arcuate wall (16) of the cylindrical body member.

Abstract: A quadrilateral assembly in an electric arc furnace wall for providing one or more coherent jets into the furnace and for providing preferably a plurality of post combustion oxidant streams into the furnace, preferably for forming a post combustion oxidant sheet.

Abstract: A feeding device for low shaft furnaces, in particular for arc furnaces for melting scrap, it being possible for the furnaces to be closed by a cover connected to a gas-extracting device, and it being possible for a charging apparatus to be set down on the furnaces once the cover has been removed from the furnace shaft. The charging apparatus has a top part and a bottom part. The top part is configured as a charging container which has a gas-permeable base which can be opened, and, in the region of its mouth, the bottom part is configured such that it corresponds with the top border of the upper furnace vessel. Provided outside the low shaft furnace is a bearing on which the charging apparatus can be set down and of which the level is considerably lower than that of the top border of the upper furnace vessel. The bearing has a connection by which it can be connected to the gas-extracting device.

Abstract: An apparatus and method for processing liquid slag and baghouse dust from a steelmaking furnace such as an EAF to recover valuable metals from the slag and dust includes a treatment vessel having a movable lower shell portion for receiving liquid slag and an upper shell portion that couples with the movable lower shell portion during heat activation of the treatment vessel. The slag is combined with silicon dioxide, a reducing agent, baghouse dust, and an inert gas before being heated to between approximately 1400° C. and 3000° C. The heat treatment results in a molten reduced iron and manganese metallic material, a treated slag layer, and an off-gas containing lead, zinc, and carbon monoxide. The off-gas is combusted, cooled, and solidified, resulting in lead oxide and zinc oxide. The slag layer is tapped, cooled, and solidified. The metallic layer is tapped for recycle in the steel making process.

Abstract: The present invention provides a system and method for collecting fumes from an arc furnace of the type typically used in metal foundries. The system provides an electrode hood with extended sides for improved collection of fumes from the vicinity of the electrodes. It also provides a movable spout hood for collection of fumes when metal is tapped. The furnace is tilted when metal is tapped. A tilting duct is connected to provide a path for emissions drawn into the hood on the furnace. The tilting duct moves with the furnace. A stationary duct leads to the bag house. The tilting duct and stationary duct meet at an interface and have facing openings that maintain a path for collecting fumes throughout the entire range of motion of the furnace. The stationary duct has a group of dampers that open and close as the furnace tilts to limit air intake to the portion of the stationary duct opening that is adjacent the tilting duct opening.

Abstract: System to plug the roof of an electric arc furnace having a main chamber or melting volume arranged below the roof and at least one electrode introduced into the main chamber, the system comprising an upper element or auxiliary roof element arranged on the top of the roof and shaped so as to define an inner chamber and at least a central aperture through which the electrode can be moved, the auxiliary roof element consisting of a plurality of pipes inside which a cooling fluid circulates under pressure.

Abstract: Aspiration system to reduce the losses of fine materials and powders from an electric arc furnace having a lower hearth suitable to contain the bath of metal material being melted, a substantially cylindrical chamber arranged above the hearth, at least one electrode arranged in a central zone of the chamber and a roof arranged to cover the chamber and provided with at least one aperture through which the fumes produced by the bath can exit, the system comprising a first aspiration sub-system arranged inside the chamber and at least another discharge sub-system arranged in correspondence with the roof, the first aspiration sub-system comprising a coil of cooling pipes arranged helical so as to define, in a vertical direction, empty zones between the spirals of pipes, the coil of cooling pipes being distanced from the cylindrical wall of the chamber to define a peripheral interspace through which the fumes can ascend towards the roof according to at least an ascensional, rotatory vortex.

Abstract: An electric arc gasifier adapts to the variable chemical components of waste products by utilizing mobile and fixed electrodes and a positioning system wherein a waste is injected into a heating chamber and broken down into elemental components capable of being recycled. A primary injection is heated by an electric arc formed between two electrodes. A secondary fluid consisting of the waste and a carrier gas is then injected and mixed with the heated primary fluid. A reaction zone within the fixed electrode of the heating chamber accelerates a resulting mixture of gases, solids, and liquids into a mixing chamber, wherein the resulting high-temperature, high pressure mixture may be combined with a tertiary spray. An efficient destructive rate stemming from the high temperature plasma formed by the electric arc allows for low cost waste processing and a means for recovering high value metals.

Abstract: Basket to manipulate scrap in cooperation with an arc furnace (11) and with means to pre-heat the scrap by means of the fumes from the fourth hole (14), the basket being able to be associated with a movable covering system (16) and including a containing body, a bottom equipped with toothed lower closing means which may be momentarily opened, and lateral extensions for moving and positioning the basket, the containing body comprising a first upper part (10a) which acts as a buffer store to temporally increase the capacity of the basket (10) and a second lower part (10b) to contain the scrap, with a capacity substantially mating with the volume of the load of the melting furnace (110) which it has to feed, wherein the second lower part (10b) is associated with cooling means.

Abstract: Method to process fumes performed on fumes discharged directly from furnaces (10) through an aperture (11) in their roof or from loading baskets (13) used to pre-heat scrap which is to be loaded into a furnace, the fumes (17) afterwards being sent to a purification plant (24) and to a chimney, the fumes (17) leaving the furnace (10) and/or the loading baskets (13) through a cooled conduit (14) being made to pass through at least a first transit chamber where they are subjected to a post-combustion process before being sent to the purification plant (24) and the chimney, the first transit chamber being a first expansion chamber and the fumes entering the first expansion chamber (15a) expanding in correspondence with a wider section (215a) therein at the entrance thereto and being deflected by a deflector element (18) arranged substantially at the center of the wider section (215a), the expansion and deflection causing the fumes to decelerate from a speed at the inlet of around 20 to 50 meters per second to a s

Abstract: An arc furnace fume collection system has a plurality of duct lines leading to a common duct that leads to a baghouse for filtering dust. The supplemental duct lines have high pressure fans, blowers, or compressors and join one of the other duct lines through a nozzle. The nozzle connection acts as a venturi to supplement the pulling power of a common exhaust fan downstream of the baghouse filter.

Abstract: Spray cooled roof assembly for a metallurgical vessel, e.g. an electric arc furnace, comprising two spray cooled components, one of which covers a major portion of the furnace, and the other component of the roof assembly having an integral spray cooled extension for the removal of heated gases from the furnace.

Abstract: An electric arc furnace comprises a closed melting vessel and includes means for charging metal to be molten into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: The present invention provides a system and method for collecting fumes from an arc furnace of the type typically used in metal foundries. The system provides an electrode hood with extended sides for improved collection of fumes from the vicinity of the electrodes. It also provides a movable spout hood for collection of fumes when metal is tapped. A combination of a tilting manifold and stationary duct are used to maintain a path for collecting fumes throughout the entire range of motion of the furnace. The stationary duct has a group of dampers that open and close as the furnace tilts. Variable position dampers may be provided at the electrode hood and furnace door. In the bag house, there is a dust containment assembly to limit the movement of the collected dust. A variable speed fan may be used with the system.

Abstract: An electric arc furnace comprises a closed melting vessel and includes a roof through which metal to be molten is charged into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: An electric arc furnace includes a closed melting vessel and includes an opening that can be closed where metal to be molten is charged into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: A melting furnace for the thermal treatment of special waste materials containing heavy metal and dioxin is provided. The melting furnace includes a main furnace vessel, the main furnace vessel having a melting end for receiving a melt, and a gas chamber above the melt. The melting furnace further includes at least one charging device for supplying a product to be treated, at least one gas outlet, and at least one discharge chamber, the at least one discharge chamber being separated from the main furnace vessel by a separating wall and being connected to the melting end by a siphon, the at least one discharge chamber having a gas chamber above the melt. At least one first heater projects into an interior of the main furnace vessel, and at least one second heater is provided in the at least one discharge chamber.

Abstract: The present invention provides a system and method for collecting fumes from an arc furnace of the type typically used in metal foundries. The system provides an electrode hood with extended sides for improved collection of fumes from the vicinity of the electrodes. It also provides a movable spout hood for collection of fumes when metal is tapped. A combination of a tilting manifold and stationary duct are used to maintain a path for collecting fumes throughout the entire range of motion of the furnace. The stationary duct has a group of dampers that open and close as the furnace tilts. Variable position dampers may be provided at the electrode hood and furnace door. In the bag house, there is a dust containment assembly to limit the movement of the collected dust. A variable speed fan may be used with the system.

Abstract: An exhaust device to suck in the fumes in an electric arc furnace (11) fed either by direct or alternating current. The furnace (11) comprises a crown (20) with at least one aperture (19) to introduce and position the electrodes (12) associated with a cupola, in a vertically raised position, which surrounds the electrodes (12) partially in a vertical direction. The cupola is smaller in diameter than the crown (20), there being included a fourth hole connected to the discharge pipe for the fumes (14). The cupola functions as a decantation chamber (13) substantially cylindrical in shape. The cupola functioning as a decantation chamber (13) including at its upper part a conduit (15) to discharge the fumes projecting tangentially and connecting the cupola functioning as a decantation chamber (13) to the discharge pipe (14), placed at the side of the cupola (13).

Abstract: A method and a d.c. arc furnace for thermal treatment of an ash, wherein reducing conditions are established within a closed and sealed furnace, the ash is supplied via a channel arranged in an electrode which extends towards a metal melt in a furnace shell and provides an arc extending toward the metal melt, the ash being fed from the open free end of the electrode through the arc, any slag and/or the metal melt, whereby the ash is rapidly heated under reducing conditions to a temperature of 1350.degree. C. to 1750.degree. C.

Abstract: An electric arc melting furnace includes a furnace shell (1) with an electrode (3) for melting scrap by heat of arc, an air blasting port (20) for blasting air, oxygen or oxygen-enriched air into the furnace shell (1) through an air control valve (19), a carbon blasted quantity indicator (CI) for measuring quantity of carbon to be charged into the furnace shell (1), a scrap charged quantity indicator (SI) for measuring quantity of the scrap charged into the furnace shell (1), an oxygen blasted quantity indicator (OI) for measuring quantity of oxygen blasted into the furnace shell (1) and an arithmetic processor (7) for computing quantity of air required for complete combustion of carbon monoxide (23) in the furnace shell (1) in response to measured value from the indicators (CI)(SI)(OI) to control a degree of opening of the air control valve (19).

Abstract: An electric arc melting furnace comprises a furnace shell (1) with an electrode (3) for melting scrap by heat of arc, an air blasting port (20) for blasting air, oxygen or oxygen-enriched air into the furnace shell (1) through an air control valve (19), a carbon blasted quantity indicator (CI) for measuring quantity of carbon to be charged into the furnace shell (1), a scrap charged quantity indicator (SI) for measuring quantity of the scrap charged into the furnace shell (1), an oxygen blasted quantity indicator (OI) for measuring quantity of oxygen blasted into the furnace shell (1) and an arithmetic processor (7) for computing quantity of air required for complete combustion of carbon monoxide (23) in the furnace shell (1) in response to measured value from the indicators (CI)(SI)(OI) to control a degree of opening of the air control valve (19).

Abstract: A melting furnace for thermal treatment of heavy metal-containing and/or dioxin-containing special wastes, including a clog preventing system including a principal furnace vessel, which exhibits a melting tank for holding a melt; at least one feeder for feeding the material to be treated; a discharge chamber, which is at a spatial distance from the feeder, the feeder being connected gas-tight via a siphon to the melting tank; the principal furnace vessel and the discharge chamber having third heating elements in the form of bath electrodes, by means of which an electric current can be run through the melt and the siphon for additional heating of the melt.

Abstract: A method for carrying out post combustion in an electric arc furnace comprising forming a preferential gas stream within the electric arc furnace, concentrating carbon monoxide within the gas stream, and providing post combustion oxygen into the gas stream where the carbon monoxide is concentrated.

Abstract: A process and low-shaft furnace for disposing of filter material. The material to be disposed of is charged via a charging device onto and/or into a slag bath in the furnace. Simultaneously, additives comprising fluxing agents, slag-making constituents and reducing agents are introduced into the slag via a separate immersion lance. Finally, during the introduction of the additives the variables forming the electrical resistance, essentially the electrodiameter, center distance between the electrodes, level of the slag bath, and the immersion depth of the electrodes in the bath are adjusted so that 70% of the electrical energy is introduced between the electrodes and 30% of the electrical energy is introduced between the electrodes and the metal bath on the hearth bottom.

Abstract: Apparatus and methods of abating the objectionable emissions of volatile hydrocarbons generated during the preheating cycle of a twin vessel electric arc furnace steelmaking operation wherein the vessels cycle between a powered or melting state and an unpowered state. During the unpowered state, scrap charged to the non-powered vessel is preheated. The spent off-gases from the non-powered vessel may contain toxic and/or noxious hydrocarbons therein by virtue of certain plastics and/or grease/oils mixed with the scrap being preheated. The spent off-gas from the preheat vessel is delivered to a combustion chamber to be mixed with a hot off-gas diverted from the powered vessel. The temperature of the mixed off-gases in the combustion chamber is raised to a critical temperature to burn/crack the objectionable hydrocarbons, which may include dioxins and furans.

Abstract: Smeltable dust and pieces of grate slag in the proportions in which they are produced by a garbage incinerator can be disposed of by simultaneously melting them in a low-shaft electric furnace having at least one electrode extending into a molten slag bath which is maintained in the furnace covered by a layer of coke. The dust is introduced below the coke layer by a lance or tubular electrode while the pieces of grate slag are introduced above the molten slag both. The proportions of the two are maintained so that the leachate from the solidified slag when deposited in a landfill, conforms to the statutory requirements of clean drinking water laws.

Abstract: An installation for the production of liquid metal by melting a charge of ferrous material, comprising at least one electric melting furnace consisting of a chamber closed by a removable roof and associated with consumable electrodes for melting the charge of ferrous material, at least one chamber for preheating the charge, and a main hot gas and flue gas removal circuit, equipped with a filtration device for removing pollutants. The preheating chamber is associated with one or more burners, and the gases produced in the chamber during preheating are sent to an auxiliary low-throughput treatment circuit equipped with an incineration chamber, and the flue gases produced in the furnace by the melting of the charge are sent directly to the main treatment circuit.

Abstract: A process and melting furnace unit are provided for extracting valuable substances by reducing oxygen-bound metals which process includes exposing a charge in a first reaction zone of a furnace vessel to heat energy so that a liquid slag floats on a metal melting bath, feeding the metal bath to a second reaction zone of the furnace vessel where the slag comes intimately into contact with a reducing agent, and feeding additional heat energy to the melt in the second reaction zone to prevent hardening.

Abstract: The present invention relates to a process of recycling filter dust obtained during the production of steel in an electric arc furnace. Filter dust is injected and mixed with the smalls of carbon containing material in the slag or at the interface between the slag and the molten metal bath in the melting tank. The process of the invention also improves the degree of efficiency of the foaming of the slag while increasing the profitability of steel production.