Abstract: A refining furnace used for vacuum refining has a sealing cover mounted on the refining furnace so as to cover the furnace throat of the refining furnace and to be in close contact with a sealing flange (10) formed on the refining furnace. The adhesion of metal and slag to the sealing flange is prevented without using any flange cover. A sealing flange (10) is formed on the outer surface of the refining furnace (1) at a position on a conical part (8) extending between the furnace throat (9) and a straight body part or on the straight body part. A slag-stopping dummy flange (11) is formed on the outer surface of the refining furnace (1) at a position between a furnace throat (9) and the sealing flange (10). The slag-stopping dummy flange (11) has an outer circumference lying on the inner side of the inner circumference of a sealing cover (4) and on the outer side of the inner circumference of a lower end part of a dust collecting hood for atmospheric refining.

Abstract: A method for after combustion of reaction gases resulting from the decarburization of liquid steel in reaction vessels under vacuum includes the steps of arranging a blow-in opening within a refractory lining of a reaction vessel and introducing an air stream, comprised of hot air of a temperature between 800.degree. C. to 1400.degree. C., counter to the flow direction of the reaction gases via the blow-in opening into the reaction vessel. A device for performing after combustion of reaction gases resulting from the decarburization of liquid steel in a reaction vessel under vacuum includes a generator, connected to the reaction vessel, for producing hot air. The generator contains a bulk of balls for heating the air guided through the bulk of balls and subsequently introduced into the reaction vessel. The bulk of balls consists of a refractory material and is heated by heat energy.

Abstract: A cold hearth furnace for refining of selected metals, such as titanium, is described. The furnace includes a melting hearth and a transport hearth arranged linearly. A pair of barriers partially block the flow of molten materials to mix it, allowing impurities to vaporize and preventing splattering of the material in the melting hearth from contaminating the final product.

Abstract: In the particular embodiment described in the specification, a cold hearth arrangement has a hearth plate forming a floor above the bottom of a melt chamber enclosure and a hearth is removably mounted on the hearth plate. Coolant supply and return lines are connected through the hearth support plate to the bottom of the hearth so that no utility lines are exposed above the floor plate. A mold, which also has water supply and return lines connected to it beneath the floor plate extends through the bottom of the enclosure.

Abstract: A method of and apparatus for degassing molten metal in a vacuum treatment chamber defined by a open topped ladle containing the molten metal and a generally cylindrical refractory lined cover having a closed top and an open bottom positioned on the ladle, with a temporary joint formed therebetween, and a vacuum seal sealing the vacuum treatment chamber from the atmosphere. A vacuum offtake is connected to the cover chamber to apply vacuum to the vacuum treatment chamber, and the molten metal is stirred to produce sufficient turbulence and splashing to produce an increased surface area of molten metal exposed to vacuum to accelerate the degassing rate. The offtake outlet is located at a height above the cover chamber open bottom to substantially prevent splashed metal and slag from being carried into the offtake while permitting aggressive stirring to increase treatment rate.

Abstract: The present invention pertains to a snorkel for a degassing vessel, with a refractory lining and a gas-purging device arranged therein with a plurality of channels, which, distributed over the circumference of the snorkel, extend through the refractory lining in the radial direction in relation to the central longitudinal axis of the snorkel and can be connected on the outside to at least one gas supply line.

Abstract: A method of refining molten metal includes the steps of reduced-pressure-refining molten metal in a heated vessel, adding slag-forming agents into the refined molten metal while keeping the molten metal in the vessel, or after pouring the molten metal into another vessel, re-refining the molten metal by heating the molten metal with inert-gas plasma and while stirring the molten metal as occasion demands. Preferably, the refining apparatus includes two adjacent chambers, each chamber isolated from the surrounding atmosphere. The chambers can be connected with, or separated from, each other and each chamber is provided with an exhaust device. One of the chambers is provided with an induction heating refining furnace, and the other chamber is provided with inert gas plasma heater. The apparatus also includes a re-refining vessel which is transferable between the two chambers, and a material feeder for feeding slag-forming agents into the re-refining vessel.

Abstract: Molten metal (e.g., on its way to a continuous casting machine for forming a bar that will be rolled into a rod to be drawn down to wire) is filtered to remove particulate impurities by passing it through at least one and preferably several ceramic filters. In addition, the molten metal is degassed by injecting a flushing gas into the metal through one or more porous plugs in the bottom of the chamber through which the molten metal flows. A partial vacuum column above each porous plug is used to help pull gas up through and out of the metal.

Abstract: The firing and/or casting kiln has a containment casing which internally forms a treatment chamber, a part holder which is movably mounted inside the treatment chamber, an opening for access to the treatment chamber, and a conditioning system for producing a vacuum and introducing inert gas into the treatment chamber.

Abstract: A vacuum plant, in particular for secondary metallurgy, having at least one ejector which is in communication with a closed container within which a metallurgical vessel which is to be placed under pressure can be brought. A second ejector is connected in series with the one ejector via an intermediate condenser having a cooling water feed line and a condensate discharge line. A final condenser and a suction pump are connected to the second ejector. A controllable condensate distributor member is provided in the condensate discharge line of the intermediate condenser. One line of the distributing member is connected to a heat exchanger and the other line is connected to the cooling water supply of a final condenser.

Abstract: A casting conduit (5) is attached at a low-level location to a completely sealable furnace (1) for a casting material (2). At this connection, the furnace is provided with an outlet opening (4) which is capable of being closed by a shutter (3). The casting conduit (5) leads down to a mold chamber (6) in which the mold (7) is located. The casting conduit (5) is closed, e.g. in the manner of a tube, and can be connected by a vacuum connection (8) to a vacuum installation together with the mold chamber (6). When the vacuum in the furnace (1) and in the casting conduit (5) resp. the mold chamber (6) is equivalent, the outlet opening (4) can be opened by means of the shutter (3), and the casting material (3) can flow into the mold chamber (6) and into the mold (7) via the casting conduit (5).

Abstract: A method and apparatus for preparing a continuous flow of castable composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at or below a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt.

Abstract: The firing and/or casting kiln has a containment casing which internally forms a treatment chamber, a part holder which is movably mounted inside the treatment chamber, an opening for access to the treatment chamber, and a conditioning system for producing a vacuum and introducing inert gas into the treatment chamber.

Abstract: There is proposed a novel method for manufacturing high-purity metallic chromium that can eliminate the problems of reduced heating capability of the furnace, contamination of produced metallic chromium and other disadvantages related to the operation of the furnace. According to the invention, one or more than one of easily sulfidable metals selected from Sn, Ni and Cu are added to crude metallic chromium containing impurities and the mixture is loaded into a vacuum furnace equipped with heating elements of graphite and heated to 1,200.degree. to 1,500.degree. C. in an atmosphere with reduced pressure of between 0.1 and 5 torr.

Abstract: Disclosed is a method and apparatus of treating molten metal for reducing the amount of gaseous or volatile material contained therein. The method comprises providing a body of molten metal and contacting the molten metal with a porous member having a porous surface resistant to penetration with the molten metal. The porous member is subjected to reduced pressure to impose a reduced pressure zone on the molten metal contacting the porous surface thereby removing the gaseous material from the molten metal through the porous member.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the inert gas is fed into the conveying conduit at a supersonic velocity, thereby simultaneously effecting a degassing of the molten metal while it is being conveyed.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the molten metal is alloyed simultaneously with its conveyance, the same inert gas being employed for both conveying the molten metal and for entrainment of the alloying metal.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, an intermittent or pulsating inert gas feed is employed to produce essentially spherical or cylindrical bubbles within the conveying conduit, thereby resulting in greater efficiency and economy because of the possibility of reducing the quantity of inert gas employed to induce the flow of an identical amount of molten metal.

Abstract: A melt is stored in a vessel, and a lower half portion of a rod-formed porous member is immersed in the melt. The porous member is made of a porous material having pores which is permeable to gas and impermeable to melts, such as molten metal, molten slag, and molten matte. When the vessel is placed in a decompression container and the portion of the porous member which protrudes above a surface of the melt is put in vacuum or under reduced pressure, gases in the melt or gases produced by reactions between components of the porous member and the melt pass through pores of the porous member and are released to vacuum or depressurized atmosphere in the decompression container. Thus, gas-forming components are removed from the melt.

Abstract: A device is described for injecting gas into molten metal, e.g. molten aluminum, in a furnace chamber. It comprises: (a) a stirring apparatus having a reservoir chamber separate from the furnace chamber, a connector portion with an orifice connecting the interior of the furnace and the reservoir for the passage of the molten metal between them through the connector portion, vacuum/pressure generating means connected to the reservoir chamber interior for alternatively and successively producing therein a vacuum for drawing molten metal into its interior from the furnace chamber and a positive pressure for expelling the molten metal therefrom into the furnace chamber through the orifice in the form of a high velocity stirring jet, and (b) gas injector means adapted to inject gas into the high velocity stirring jet such that the gas is broken down into a large number of small bubbles which are circulated throughout the furnace chamber with the stirring jet.

Abstract: The invention relates to a process and apparatus for manufacturing low-gas and pore-free aluminum casting alloys by vacuum degasification and densification of the melt. Contact between the aluminum melt and the atmospheric humidity of the alloying process, from refining to continuous casting of the cast bars, is kept extremely short, so that effective vacuum degasification, and a high cooling rate, can prevent the formation of gas pores. After the metal melt is alloyed in a smelting furnace, the melt is fed through a system of gutters directly to at least one vacuum furnace. Refining components are added in the vacuum furnace and heating is conducted to provide the pouring temperature required for continuous casting.

Abstract: A melt is stored in a vessel. A lower half of a degassing member is immersed in the melt. The degassing member has a cylindrical form with the lower end closed, and the lower half section is made of a porous material which is permeable to gas and impermeable to melts as molten metal, molten slag, or molten matte. This lower half section is a partitioning member. When an internal space inside the degassing member is sucked to realize vacuum or reduced pressure atmosphere, gas producing components in the melt pass through the partition member of the degassing member, and are exhausted to inside the degassing member, thus being separated from the melt. Also, by making the degassing member rotate or move in a horizontal or vertical direction, the melt is stirred. With these features, gas-producing components in the melt can be removed at a high efficiency.

Abstract: A unit for the metallurgical treatment of molten steel, located in steel teeming ladles, by heating and vacuum treatment. The ladle-metallurgical treatment unit serves for the mutual treatment of steel meltings by heating and vacuum treatment. It consists of two treatment stations, each of which is provided with a stationary tank 1, 2 for incorporating the steel teeming ladle 3, 4, and each is provided with a laterally movable vacuum lid mechanism 13. A heating device with a swiveling heating lid 9, which is arranged centrally between the two treatment stations, is brought into the working position over one of the two steel teeming ladles 3, 4.

Abstract: An apparatus for heating molten metal including a ladle provided with a refractory heat insulating material and first core members arranged in pairs and attached to the outer circumference of the ladle. A tray capable of mounting said ladle carries second cores with magnetic pole portions at both ends of said cores as to face the ladle mounted first cores. A coil is provided for exciting the second cores. The first cores and magnetic pole portions of second cores are located at the outer circumferential portion of the ladle to face each other radially in a manner to facilitate placement and removal of the ladle to and from the tray. Position sensors are provided to ensure positional accuracy of the first ladle carried cores and the poles of the second cores. The coils are physically and thermally protected from ladle heat by appropriate shock absorbing and thermal insulating provisions. Thermal protection of the cores can be further enhanced by cooling embodiments.

Abstract: Part of a melt vessel is formed from a porous member which is permeable to gas and impermeable to melts. Alternatively, a bottomed cylindrical partitioning member immersed in a melt in the melt vessel, or part of a circulating vessel through which the melt circulates, or a dam disposed in the course of circulation of the melt in the melt circulating vessel is formed from the porous member.Vacuum pump is used to suck gas from the melt or gas produced by a reaction at the interface between the melt and the porous member through the porous member, to the side of that surface of the porous member which is not in contact with the melt and kept at a vacuum or at reduced pressure.Then, the pressure at the interface between the melt and the porous member is lowered, and a space which is in a vacuum or at reduced pressure can be easily created in the melt. Thus, solute ingredients of the melt nucleate easily to form gaseous substances, so that the gaseous substances are sucked into the space and removed from the melt.

Abstract: A vessel for processing steel under vacuum is provided and includes a vessel body, a cover placed thereupon in a vacuum-tight manner, and a connection for a vacuum pump. To heat the vessel a heating mechanism is provided that comprises a graphite rod that extends diametrically through the vessel, with contact studs being provided at the ends of the graphite rod for the transfer of electrical power. To increase the service life of the graphite rods, the rod with its contact studs is fixably held in position on the vessel wall at one end, and at the opposite end the rod is displaceably disposed relative to the vessel wall. To compensate the force originating from the vacuum that prevails in the vessel, a compensating mechanism that is acted upon by the vacuum of the vessel is provided for supporting the moveable mounting of the graphite rod.

Abstract: A multi-chamber vacuum installation includes a charge-changing chamber (5) and a plurality of processing chambers (1, 2, 3, 4) located within the charge-changing chamber. One of the processing chambers (4) also serves as an air lock chamber. The air lock chamber (4) is formed of two parts, and inner part (4a) and an outer part (4b). The inner part is secured to the inside and the outer part is secured to the outside of the charge-changing chamber.

Abstract: The invention provides a new stirring apparatus for stirring the liquid metal contents of a furnace, particularly the shallow furnaces used in the processing of aluminum and its alloys. The apparatus consists a reservoir separate from the furnace of relatively large horizontal cross-section and volume, into which a vaccuum draws metal from the furnace through a nozzle, the metal then being returned by gas pressure forcibly into the furnace through the nozzle in the form of a horizontally directed jet. The cycle is repeated at sufficiently close intervals to ensure that the furnace bath is quickly and effectively mixed. The nozzle directs the molten metal entering the reservoir tangentially to swirl the metal and reduce the accumulation of dross. The reservoir comprises a bottom static part including the nozzle and a readily removable top cover carrying heaters for heating the reservoir interior and the dross that deposits on the side wall to ease its removal.

Abstract: An apparatus for melting and pouring metal alloys includes a vacuum melt furnace having a melt chamber to receive and melt metal in a vacuum. A valve cooperates with a pour opening located at the bottom of the furnace. The valve includes an upper stationary nozzle portion formed substantially from refractory material and having an orifice aligned with the pour opening. A lower nozzle portion having an orifice therethrough is mounted adjacent and below the upper nozzle portion for slidable movement along a lower face of the upper stationary nozzle portion. The valve is opened and closed by slidably moving the lower nozzle orifice in and out of alignment with the upper nozzle orifice. An induction heating coil substantially surrounds the upper stationary nozzle portion.

Abstract: An easy method and apparatus to eliminate casting defects from composite materials of hypereutectic Al-Si alloys and improve their properties. The product composite materials with primary silicon crystals of several microns have fine honogeneous microstructures and mechanical properties comparable to similar materials produced by the conventional powder metallurgy technology. Highly wear-resistant composite materials, in which the hypereutectic Al-Si alloy and strengthening material are homogeneously mixed, can be obtained with ease. The hypereutectic Al-Si alloy and strengthening material are homogeneously mixed by stirring blades rotated at low speed. The obtained molten composite alloy rotated at high speed about a horizontal shaft in a heat-resistant vessel. The rotor rotating and stirring at high speed spatters the molten composite alloy material to break up the crystallizing out primary silicon crystals.

Abstract: A process and charge material prepared thereof for metallugical fusion processes is disclosed. In the process, at least two alloy components are combined in a nonreactive atmosphere. A support is provided which is made of at least one of the components and the other component is condensed from a vapor phase onto the support to form a condensate. The support is positioned in a holding means in the vapor phase of the alloy component and may be either a plurality of hollow tubes or a foil rolled through the vapor phase from a supply roll to a take-up roll.

Abstract: The invention concerns a process for the production of metal Zr by means of molten Mg in a reactor 1 having a hearth plate 3, comprising separating the magnesium chloride formed in the reduction reaction from the metal Zr formed. The process is characterized by separating the magnesium chloride formed by tapping off towards the bottom of the reactor 1 by means of a chimney 6 whose bottom end portion 5 is fixed to an orifice 4 in the hearth plate 3 and whose transverse open top end 7 is above the portion of the metallic mass Zr, Mg which borders the chimney 6 at the end of the reduction reaction. The invention also concerns the corresponding apparatus for the production of metal zirconium. The invention provides a simplification in the operation of separating the MgCl.sub.2 formed and possibly, by virtue of a particular structure of the chimney according to the invention, gives an improvement in the operation of extracting the sponge cake produced.

Abstract: With an airtight reaction vessel having a lining of refractory material for immersion in steel-processing ladles, especially for processing steel pursuant to the vacuum circulation process, including an upper vessel part, a lower vessel part, and immersion pipes, whereby these parts are interconnected via flange rings and clamping mechanisms that hold them together, the seal between the vessel parts is to be improved in every operating state. For this purpose, it is proposed that the respectively upper main flange (17) of the associated respectively lower vessel part (11, 13, 15) have a separate upper flange ring (19) that is placed upon the resilient end of an interposed compensator ring (20) and that in the unstressed state of the flange (17, 19) extends slightly beyond the upper rim of the vessel part (11, 13, 15).

Abstract: In an installation for the vacuum heat treatment and subsequent hot isostatic redensification of materials comprising a work space inside a container, heating unit, work-space insulation and an outer chamber with a vacuum connection and a pressure-gas connection, insulation is also provided at the interior of the chamber wall. The chamber is water-cooled.

Abstract: A method of continuously casting a metal and an apparatus for continuously casting a metal wherein such a metal as copper, aluminum and so on is degassed continuously by means of at least two vacuum chambers which are installed over a preserving container for preserving a molten metal before being introduced to a mould and one of which pumps up the molten metal for degassing thereof while the other of which exhausts the molten metal after degassing thereof.

Abstract: A lance supporting device has a lance turntable rotatable within a plane and carrying a plurality of lance operation units each supporting a lance for inserting a gas and/or a powdered treating agent into a molten metal. Each lance operation unit has means for lifting/lowering, rotating and tilting the lance. The lance turntable carrying the plurality of lance operation units is disposed in the central hollow or cavity of a doughnut-shaped turntable which carries a plurality of vacuum degassing vessels.

Abstract: In a continuous steelmaking method, a molten metal bath is maintained within a rotary furnace heated by oxy-fuel burners at the charge and discharge ends. Metallic iron charge material such as iron and steel scrap or sponge iron is preheated primarily by heat transferred from the furnace exhaust gases, on an enclosed recuperative conveyor before being introduced through the charge end opening. Molten metal is withdrawn through a siphon tube submerged in the bath through the furnace discharge end opening into a vacuum chamber which is part of an integral vacuum chamber-tundish combination incorporating a molten metal column under vacuum in one leg and a molten steel tundish casting pool under atmospheric pressure as the other leg, connected via a submerged channel.

Abstract: A leg is fitted through a joint material into each of a pair of vertical openings on a bottom wall of a vacuum tank for refining molten steel, for protecting the vertical openings from molten steel. The abovementioned leg has an annular inner wall formed by piling up through a joint material a plurality of magnesia-chrome fired radial bricks in a plurality of horizontal annular rows arranged one on the other so as to form an inner bore for passing molten steel therethrough. The leg also has an annular outer wall formed by piling up through a joint material a plurality of magnesia-chrome fired radial bricks in a plurality of horizontal rows arranged one on the other so as to cover substantially the entire outer surface of the annular inner wall. The inner surface of the annular outer wall is in contact with the outer surface of the annular inner wall through a joint material.

Abstract: The present invention provides a process for the refining of metal by the removal of unwanted constituents 11 therefrom. The process comprises melting down the metal 8 under an atmosphere in which the ratio of the partial pressure of non-deleterious gas 6 to the partial pressure of deleterious gas 10 is at least 10:1. The invention also provides an apparatus comprising a vacuum induction melting furnace 3, a vessel 2 for holding metal 8 and gas exhaustion means 4 for extraction of gas from the furnace 3. A gas supply means 6 is formed and arranged 5 for directing a flow of gas substantially directly at the mouth of said vessel 2.

Abstract: An apparatus for removing gases from molten metal, especially from molten aluminum. A ceramic or similar melting receptacle or crucible is accommodated in a furnace. A partial pressure is produced between the removable cover of the furnace and the surface of the molten material. Between the upper rim surface of the crucible, which is made of ceramic material, and the cover, there is disposed an intermediate ring which supports this cover. A sealing ring is disposed between the intermediate ring and the rim surface of the receptacle. This sealing ring is made at least partially of fibrous material which can resist high temperatures. At a surface pressure of greater than 15 kp/cm.sup.2, the sealing ring has a compressibility of at least 10% of its cross-sectional area.

Abstract: Molten steel or other electroconductive metal is treated with vacuum to remove dissolved gases therefrom. A rod of molten steel is drawn from a bath by applying vaccum to a vertical tube dipping into the molten bath. An electrical coil surrounding the tube applies an intense magnetic field to the steel rod by the passage of high frequency alternating current through the coil. The rod is compressed radially inwardly by the magnetic field exposing the whole of the external surface of the rod to vacuum. At the same time, the induced eddy currents superheat the steel rod. The large surface area of application of vacuum combined with the narrow dimension through which the gas must travel ensure rapid and efficient removal of the gases. The procedure is repeated until all the steel in the bath has been treated.

Abstract: The present invention includes a plurality of ceramic oxide wall panels which are defined by a thickness dimension, depth dimension, and width dimension. The ceramic oxide panels are beveled along their width sides so that when they are held together along their width sides, they form a closed plane, that is a polygon or a substantial circle configuration. At each abutment position of two adjacent wall panels, there is formed an abutment angle. In addition a plurality of overlap support panels of ceramic oxide is employed and each is formed to have an angle which fits over an associated one of said abutment angles. Each overlap support panel is secured to, and partially overlays, two abutting wall panels, thus providing support for said two adjacent abutting wall panels. In a preferred embodiment each overlap support panel abuts two adjacent support panels.

Abstract: The invention relates to a vessel for the continuous treatment of molten metals under reduced pressure, according to the circulation process. In order to increase the through put of the molten metal, the inlet and outlet pipes are located on the longitudinal axis of an elongated vessel-bottom, for example an elliptical vessel-bottom, a cross-section of the inlet and outlet pipes being enlarged. The lower portion of the vessel is bell-shaped. With this geometry of the lower portion of the vessel, the volume of the vessel remains small, despite comparatively large cross-sections of the inlet and outlet pipes, which can be located with an adequate clearance from each other and the walls of the vessel, so that the danger of erosion effects resulting from the circulating molten metal remains small.

Abstract: A metallurgical furnace is disclosed which carries out the several steps involved in the liquid phase sintering of preforms of powdered metals, ceramics, and/or combinations of these materials. The metallurgical furnace comprises a pressure vessel defining an interior pressure chamber and a main furnace which is contained within the pressure chamber and spaced inwardly from the walls of the pressure vessel. The main furnace comprises a bottom wall, side walls, top wall and end walls which together form a substantially closed furnace chamber. Each of these furnace walls comprises at least one layer of insulation and, in addition, the top, sides, and end walls further include a vapor barrier which minimizes convection within the furnace chamber. The metallurgical furnace according to the present invention is capable of performing the presinter, sinter and hot isostatic pressing of preforms within the furnace chamber.

Abstract: A molten metal is fed into a ladle and subjected to vacuum while being treated with inoculating additives. The application of vacuum is carried out prior to the beginning of interaction between the melt and the inoculating additives, and is conducted continuously for 15 to 120 seconds in the course of this interaction. A receiving tank is provided with a discharge opening which is closed with an insert, a ladle having load trunnions is disposed under this tank with a sealable chamber. A system of air evacuation is provided for the chamber whereby on disintergration of the insert the molten metal with tank enters the chamber and is subjected to the vacuum.

Abstract: Gases can be introduced in a finely divided form into molten metal using a jet-mixing facility which is designed on the Venturi principle and is made of a suitable refractory material. Melt flow rates of 2-100 m/s are measured in the cylindrical center piece of this mixer, and gas is sucked in at a reduced pressure of 0.05 to 0.9 bar. By means of this process an injector efficiency (ratio of throughput of propellant to throughput of purifying medium) of 3.75-4.0 is achieved.

Abstract: One form of the invention discloses an apparatus and a method for positioning the snorkel of a vacuum degassing apparatus beneath the interface of the molten metal and slag in a ladle utilizing means for determining the interface, which means comprises an electrode adapted for positioning within the ladle in electrical contact with the material, indicating means for indicating a first range of voltages produced at said electrode by an electrochemical reaction between the molten metal and the electrode as well as a second range of voltages produced at the electrode by an electrochemical rection between the slag and the electrode, with means for supporting the electrode independently of the ladle and adapted to enable the electrode to be raised or lowered within, and relative to, the ladle, wherein the electrode is moved to a position within the ladle and relative movement is subsequently produced between the electrode and the ladle whereby the position of the interface will be determined by noting a change in

Abstract: A method for producing a killed molten steel for continuous casting, which comprises;A step of preparing a molten steel with a blow-off carbon content not less than 0.05% in a converter,A step of pouring the molten steel to a ladle, andA step of degassing the molten steel in vacuum degassing vessel under a vacuum within a range of from 10 to 300 mmHg, with addition of at least one element selected from the group consisting of Al, Si and Mn, while stepwisely adjusting the vacuum in correspondence to the degree of decarburization of the molten steel.

Abstract: A method for producing steels within a very close analysis tolerance in which the raw materials are melted down in a first vessel, the melt is then tapped into a second vessel in which deslagging is accomplished, and thereafter the melt is subjected to treatment under a vacuum. An apparatus for carrying out the method is also described.

Abstract: Apparatus for the continuous vacuum refining of a metal comprising a cylindrical vacuum chamber, containing a stack of a plurality of vertically superposed trays. The trays receive impure molten metal which flows downwardly from tray to tray while impurities are discharged therefrom and flow to shields which surround the trays and condense and discharge the impurities. The metal in the trays is heated to evaporate the impurities therefrom. The heat energy which is imparted to the metal is effected irregularly along the height of the stack of the trays such that the imparted heat energy diminishes in a vertically downwards direction.