Abstract: Apparatus for applying heat to a reservoir (27) of molten metal, comprising a plasma torch (48) and a metal contact electrode (52) to complete an electrical circuit with the torch (48) via the molten metal in the reservoir (27). The plasma torch (48) and the metal contact electrode (52) are both mounted on a stand (51) for up and down movements as a unit so as that the plasma torch (48) is moveable downwardly into proximity with the surface of the reservoir of molten metal and the metal contact electrode is simultaneously insertable into the molten metal and withdrawable therefrom. The metal contact electrode (52) is formed with an interior passage (63) for flow of gas therethrough into the molten metal and there is provided a gas pressure detector (65) to detect a change in gas pressure consequent on breakage of the metal contact electrode (52).

Abstract: An apparatus and method for reclaiming metal chips formed while machining metal castings to their finished shape. The apparatus includes a stationary charging tube extending in a generally perpendicular direction from the charge well of a reverbratory furnace. The lower end of the charging tube is attached to a box-shaped structure which has an open bottom. The sides of the structure extend into a pool of molten metal contained in the charge well. A variable rate feeder provides a continuous supply of metal chips to the charging tube at a rate which is essentially the same as the rate at which the chips are being produced. The chips form a column within the charging tube which extends through the box-shaped structure and into the pool of molten metal. As the chips at the bottom of the column are melted, additional chips are added to the top, forcing the bottom of the column of chips into the pool of molten metal.

Abstract: An apparatus and process for the free-forming manufacture of three-dimensal components. A powder-binder mixture, or a material with a high melting point, is plasticized or made molten, by raising the temperature inside a process chamber. The resulting molten material is discharged under pressure through a nozzle which is arranged at the end of the process chamber. The material inside the process chamber is deposited in layers. The processing direction and processing speed of the nozzle are programmed. An embodiment of the invention is disclosed in which a non-molten powder is deposited and supported by the deposition of a second powder alongside the non-molten powder.

Abstract: In a charging material preheater for a metallurgical smelting plant having a shaft (5) which has closure members (7, 8) which are pivotable by a control member (6) and which include fingers (9, 10) which are arranged parallel and at a spacing relative to each other, the fingers (9, 10) of a closure member (7, 8) are mounted with a central portion in a first rotary mounting (12, 13) and in a second rotary mounting (21, 22) of the frame structure (2) with an outer portion which is passed outwardly through an opening (14, 15) in the shaft wall, by way of an elbow lever mechanism (16, 17), and lever arms (18, 19) of at least two elbow lever mechanisms are connected together by a connecting member (23) which is pivotably engaged by a control member (6) which is supported in a third rotary mounting (26, 27) of the frame structure (2).

Abstract: Apparatus for a fully automated magnesium melt system. Raw magnesium ingots are moved through and controllably heated in a preheater chamber before they are introduced into a melt cell. A probe monitors the metal level and a control unit causes ingot charging as determined by a process level set point or temperature overshoot. There are two zones of heating in the melt cell with each zone supplied by its own 3 phase zero cross fired silicon controlled rectifier and firing board which is gated by a gating signal. This controls how much the SCR's are allowed to conduct. The amount of error between the metal bath set point and the actual metal bath temperature automatically determines how much of the 4-20 mA gating signal is required to maintain the set metal bath temperature. Liquid magnesium is transferred from the melt cell to a die cast machine by a siphon transfer tube which has two sets of electrical heating elements.

Abstract: An injection needle melting/destroying device comprising an A(D)C power supply, a power indicator lamp, a transformer having output terminals, two opposite metal plates disposed beside the output terminals of the transformer to define a socket, a collection box disposed under the metal plates and a brush disposed above the metal plates. An injection needle is adapted to be inserted into the socket to make a short circuit so as to produce great current for melting the injection needle. The brush serves to cover the socket and prevent spark from splashing outside the socket during the melting operation.

Abstract: An ignitable material is positioned in contact with a slag contained within a plasma arc treatment system having an electrode and an electrical ground. The slag is initially at a temperature below a conducting temperature at which the slag will conduct electricity between the electrode and grounding network. The ignitable material has a self-sustaining reaction which releases heat energy upon ignition. The ignitable material is ignited with a pilot arc thereby heating at least a portion of the slag to the conducting temperature so that an arc between the electrode and grounding network can be sustained.

Abstract: A method and system for synthesizing nanocrystalline material. A system includes a chamber, a nonconsumable cathode shielded against chemical reaction by a working gas not including an oxidizing gas, but including an inert gas, a consumable anode vaporizable by an arc formed between the cathode and the anode, and a nozzle for injecting at least one of a quench and reaction gas in the boundaries of the arc.

Abstract: A method and apparatus are provided for making steel alloys directly in a tundish. Base steel enters the tundish from a ladle. An alloying chamber having a plurality of inlets is positioned above a tundish drain. An alloying material (for example, a wire including one or more alloying ingredients) is fed into the alloying chamber through a feed pipe originating above the liquid level in the tundish. Molten base steel enters the alloying chamber through the inlets and is mixed with the alloying material to make a steel alloy, which exits through the drain. The method and apparatus are especially suitable for making small order quantities of alloy steel of less than one ladle volume.

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 molten salt process vessel for treatment of hazardous materials such as explosive or propellant waste, employing a tall, thin vessel with sufficient height that salt splash from the molten salt at the bottom of the vessel can be controlled and hard salt deposits are prevented from forming on the walls which restrict the gas outlet. The vessel, e.g. of cylindrical shape, has an increased height to diameter ratio in the range of about 7:1 to about 12:1, to give additional clearance. As an additional feature the vessel diameter can also be adjusted to create a "necked-down" region just below the gas outlet duct adjacent the top of the vessel to increase product gas velocity of the gas containing entrained salt particles, to prevent sticking of such particles to the vessel walls and restricting the gas outlet duct.

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 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 and apparatus for feeding iron-bearing particles into a metallurgical furnace such as an electric arc furnace, comprising a vessel for containing a bath of molten iron, having a wall extending above the bath of molten iron, a preferably screw type feeder mounted on the exterior of the vessel, a feeding port in the vessel wall shaped to permit passage of the feeder into the interior of the bath of vessel and located at such a height from the molten iron so that no molten materials will spill out from the furnace through the port during the normal operation and maneuvering of the furnace; and actuating means for extending the screw type feeder from a retracted position out of the vessel to an extended position into the vessel.

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.

Abstract: An apparatus for the treatment of metal-laminated plastics scrap and/or radio, television or computer scrap, wherein the scrap is heated in a closed container to a temperature at which the metal-plastic bond is broken and the metal and plastics parts are segregated from each other. The apparatus comprises a heatable container which is provided with a closable scrap charging opening and a closable products removal opening. An inert feed conduit and inert gas removal conduit are connected to the container which is formed as a rotary tube. An inert gas washing chamber is provided between the inert gas removal conduit and the inert gas feed conduit.

Abstract: In a metallic vapor condenser for use in recovering, in the form of liquid metal, metallic vapor of a metal having a medium boiling point, the liquid metal of the molten metal is sent from a splash chamber to be circulated through a skimming sump, a cooling sump, and a casting bath to the splash chamber. The liquid metal is always refreshed by circulation in the casting bath to avoid solidification of the metal. A subsidiary chamber may be coupled to the splash chamber to reverve the liquid metal to decrease dust and dross floating on the liquid metal.

Abstract: An apparatus for eliminating chevron cracks or other imperfections in the surface of elongate billets as billets pass vertically downwardly through a heating chamber, including a plurality of plasma arc torches. The heating chamber contains a billet mold having an opening complementary in size and shape to the cross-sectional shape of the billet. Heat imparted to the billet in the upper portion of the chamber melts surface portions of the billet. Molten material discharged from the surface portions of the billet forms a pool in an area above the mold opening. As the billet passes through the pool, some of the molten material reattaches itself to the billet surfaces. Billet conveyors pivotally movable between horizontal and vertical positions transport billets to and from the heating chamber, and control the rate at which the billets move through such chamber and through a cooling chamber located beneath the heating chamber.

Abstract: A gas flushing apparatus for use with a metallurgical vessel is disclosed which is operable to allow for adjustment of the flow rate of gas through the gas flushing apparatus into molten metal contained in the metallurgical vessel. Such adjustability is provided according to the invention by providing at least a pair of discrete gas-permeable portions extending through the gas flushing apparatus from a bottom end thereof to a top end thereof. The discrete gas-permeable portions are individually connected to a gas supply by a gas distribution mechanism. The gas distribution mechanism is operable to distribute gas from a supply line to either or both of the at least two discrete gas-permeable portions of the gas flushing apparatus. The gas-permeable portions can be formed with cross sections which differ in shape from the lower portions of the gas-permeable portions to the upper portions thereof. Also, the two discrete gas-permeable portions can be provided with differing cross sectional areas.

Abstract: Apparatus and a method for producing submicron and smaller metal alloy pacles using a main chamber having a longitudinal axis and a feeder for introducing a quantity of molten alloy under pulsed gas pressure in a direction generally radial to the axis. The feeder has a gas stream for forming metal droplets from said alloy. A gas accelerator directs axially flowing gas against the droplets from the feeder in the chamber. The accelerator directs the droplets in an axial direction to a substrate located along the axis and in the direction of flow from the accelerator to receive the droplets at a predetermined distance from the feeder, whereby the particles are produced.

Abstract: The present invention is for a device for rapidly solidifying a material and a method of using the same. The device provides for containing a molten pool of material in a solid skull with the same composition as the molten material. The skull is preferably held in a cavity of an inductor which is heated by an induction coil. Means are provided to maintain a small temperature gradient in the skull so as to minimize segregation which can lead to compositional fluctuations. It is preferred that the minimum temperature in the skull is between about 0.7 and 0.95Tm, where Tm is the melting or solidus temperature of the material.Feed means provide material to the molten pool causing it to spill over onto a moving chill surface. Preferably the chill surface is cooled by a molten stream of liquid gas.

Abstract: The invention relates to an apparatus for pulverizing at least a jet of a quid or solid material in a standing ultrasonic field which is generated between at least a pair of ultrasonic devices. To increase the pulverizing capacity a plurality of pulverizing fluid jets and in addition supplementary fluid jets, for example a gas is introduced through separate nozzles at each nodal pressure area of the standing ultrasonic wave. In addition the pulverizing capacity is further increased by providing special horn shapes of the ultrasonic devices.

Abstract: A support plate, together with the shell of an aluminum holding and/or refining vessel, in combination with a refractory sheet positioned on the inner wall of a graphite block in which a heating element assembly is positioned, is used to hold and seal the heating assembly against exposure to air, without the need for enclosing the heating elements in a metal heating element container.

Abstract: A high temperature gas fired heat transfer system ideally suited for melting metals is disclosed. The system generates a heated, reducing furnace atmosphere which prevents formation of metal oxides when the metal is melted. A unique arrangement is provided to draw a portion of the reducing atmosphere from the furnace and combust the drawn furnace atmosphere with high speeds jets of preheated combustion air which convectively impinge and heat the surface of an object to a super heat temperature. That surface is then moved into the furnace enclosure to indirectly heat by radiation and melt the metal at high throughput rates.

Abstract: An aluminum furnace charging system including a movable charger assembly, a hydraulically operated ram assembly, a hydraulically operated elevator and aluminum furnace having a hydraulically operated door whereby aluminum billets and/or scrap aluminum loaded onto the elevator is automatically and quickly charged to the furnace so that heat loss from the furnace and escape of molten aluminum from within the furnace is minimized.

Abstract: A method and apparatus for avoiding the formation of impurities in a coating produced by hot-dip galvanizing of an object in a zinc bath. One or more flows of molten and pure zinc are, in a container, provided which are directed towards a surface region (4), i.e. the working surface (4), where the object passes on being immersed in and raised from the bath, respectively. As a rule, a surface flow is caused to pass from the one edge region (27) of the container, to its other edge region (29), any possible impurities (6) located on the surface of the bath being displaced from the working surface. The apparatus according to the disclosure includes a pump (25a) which, via a discharge pipe (33) supplies molten zinc to a gutter (26) in the upper region of a container (10). Opposing the gutter, the container is provided with a channel (31). The gutter and channel, respectively, have opposing walls with respective edges (27) and (29) over which molten zinc passes.

Abstract: In the particular embodiments of the invention described in the specification, a hearth for melting and refining metal has a hearth bed with cooling pipes so that a skull of molten metal is formed and energy input devices are directionally controlled to permit the skull to form a barrier between a melting region where solid material is introduced into the hearth and a refining region where molten material is refined before being poured into a mold. In one embodiment, the barrier formed by the skull provides a dam with a narrow channel between the melting region and the refining region, and in another form, the barrier provided by the skull consists of spaced peninsulas extending from opposite sides of the hearth to provide a serpentine path between the melting region and the refining region.

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: A process for melting metal scrap, particularly steel scrap or such high-melting charge material in a shaft furnace operated in cokeless manner by means of fluid fuels is described. The furnace shaft used for carrying out the process is separated from the furnace hearth connected to the bottom thereof by means of a cooled grate arrangement. The burners issue substantially vertically to the longitudinal axis of the shaft into the furnace and the combustion air is recuperatively preheated by means of the shaft furnace waste gases. The amount of heat introduced into the melting unit by means of the burners is subdivided in dosable manner into a component drawn off from the furnace shaft and a component remaining in the furnace hearth. For this purpose the radiating surface of the wall lining in the furnace hearth is between 1.5 and 3.5 m.sup.2, particularly 2 and 2.8 m.sup.2 ton of molten metal produced. The radiation-active, average layer thickness of the gas in the furnace hearth is between 1.5 and 3.

Abstract: Apparatus and method for charging metal chips into a molten bath of the metal from which the chips are formed, comprising a compacting extruder and a delivery conduit which is resistant to the mass of molten metal and which is pivotable to dip into the molten metal bath when chips are being charged thereinto and out of contact with the bath when charging is to be discontinued, are disclosed. The chips are forced through the delivery conduit in the form of a compacted or densified mass preferably having a density between about 30 and 60 percent of the density of the solid metal and preferably between about 55 and 80 pounds per cubic foot. Feed is continued while the delivery conduit is in the molten metal bath and until it is removed therefrom to prevent entry of molten metal into the delivery conduit. The method is preferably conducted on a continuous basis and various sensors with appropriate wiring may be employed for safety and for making the method substantially automatic in operation.

Abstract: A compound powder being comprised of a noble metal and of a nonnoble metal oxide is produced under atomization of salts of these metals in a watery solution and under further utilization of a hot reactor wherein a droplet containing gas flow is moved inside the reactor by operation of a pressure differential produced by a water pump, the powder particles are gravity separated from reaction gases by gas flow reversal at a temperature above the dew point of the gas and the gas is scrubbed following condensation of any water vapor.

Abstract: A system for continuously removing and transporting trimmed edge metal scrap material in the form of a indeterminate length of ribbon from a strip edge trimming or slitting station in a strip processing line to a final disposal station wherein the trimming station can be advantageously disposed in the path of travel of the strip of metal being processed. In a preferred embodiment of the invention, the said system includes a curvilinear enclosed conveyor means, one open end of which is disposed in the area of the trimming station and the other open end of which is disposed adjacent to the disposal station for continuously capturing the trimmed edge metal scrap material from the trimming station as it is cut from the moving strip of metal and then directing it to the disposal station at the proper rate of speed.

Abstract: A support plate is used, together with the shell of a vessel for the holding and/or refining of aluminum, in combination with a refractory sheet and a metal heating element container positioned in a graphite block to protect said heating element and to thus extend the life of said heating element. Oxidation of the graphite block is precluded, as is the attack upon the heating element by chlorides passing through the pores of said graphite block.

Abstract: In the production of alloy by evaporation from an evaporation bath and condensation under vacuum, charge replenishment is achieved by a procedure involving bleeding charge from the bath and admixing the bled charge with replenishment material and introducing replenishment from the admixture. An apparatus for use in the process comprises a mixing passageway encompassing an evaporation bath and distributed sub-surface bleed ports and feed ports linking the evaporation bath and the mixing chamber. Flow of metal through the ports is induced by pumped circulation in the mixing chamber. The circulation is turbulent for good mixing of the metals.

Abstract: A process for the introduction of metal chips, especially scrap metal chips, into a molten mass of the metal of which said chips are formed, wherein the essentially dry chips are first compacted and placed into strip form, and then introduced into the molten metal bath in such strip form in an essentially continuous manner, is disclosed. A cleaning flux is also advantageously incorporated with the chips, into the compacted and strip form thereof, and then into the bath. The metal chips, after compacting and placing into strip form, are introduced directly into the molten metal bath through the skin of metal oxide existing on its surface and caused to become a part of the metal pool beneath the surface thereof without essential disturbance of the metal oxide skin except at the point of introduction.

Abstract: A system for adding alloying material to molten metal media is disclosed. The system includes spark cup means, preferably cylindrically shaped, which is partially immersed in the molten media. The spark cup preferably has a lower open end which is exposed to a submerged surface of the molten media and an upper inlet, at least a portion of which is located above an exterior surface of the molten media. Means for supplying the spark cup means with an arc shielding gas through the inlet is provided as is means for feeding an elongated form of the alloying material through the spark cup inlet into the cup area or chamber of the spark cup. Also provided is means for establishing an electrical arc discharge between the submerged molten metal surface and the free end of the alloying element in the spark cup. The free end of the alloying element is converted into a spray of superheated alloy materials as it passes through the arc discharge.

Abstract: As apparatus and method is disclosed which is adapted to melt metallic fines, and which is useful for processing metallic fines into a useful form. The apparatus may also be used in the smelting of metallic oxides, and in combining metals in an alloying process. The disclosed embodiment of the apparatus includes a furnace having a hearth, a pair of tubular residence chambers each extending upwardly from the hearth, a first plasma torch mounted at the upper end of each residence chamber, and a second plasma torch mounted for heating the material on the hearth. The powdered or granular material is fed into the upper end of each residence chamber, such that the material is at least partially melted from the heat of the first torch while falling through the residence chamber, and the material is further heated and completely melted on the hearth by the second torch.

Abstract: Process and apparatus for pyrometallurgically treating finely divided ores, concentrates, residues, slags and like materials. The process utilizes a reactor having two co-axially extending, vertical reaction chambers. The process comprises forming within the upper chamber of the reactor hot fuel-rich reaction gases; passing the hot fuel-rich reaction gases by dump flow into a second vertically extending chamber; introducing into the second chamber the finely divided materials to be treated; and reacting the finely divided materials with the hot fuel-rich reaction gases. The dump flow of hot fuel-rich reaction gases passing into the second chamber is produced by providing a zone of sudden expansion in the flow passage between the first and second chambers.

Abstract: An apparatus and process are disclosed for utilizing solar radiation and the energy contained therein for the carbothermic reduction of a metal oxide to a metal carbide. The apparatus comprises a reflective surface which collects and focuses solar radiation onto a focal mirror which consequentially reflects and focuses the solar light rays into a reaction chamber through a Fresnel lens and a transparent window provided on the chamber. The solar light rays are focused by the reflective surface focal mirror and Fresnel lens such that the energy absorbed by reactants in the reaction chamber is sufficient for the carbothermic reduction of the metal oxide.

Abstract: A system for alloying lead with minor amounts of alloyants which have a higher melting point than, and a lower solid solubility in, lead. The system includes a melting furnace retaining Pb melt at a first temperature, a sealed vessel containing chunks of alloyant-rich material, a heated conduit between the furnace and the vessel for conducting melt to the vessel while heating it to the melting temperature of the material in the vessel, a conduit for returning superheated melt from the vessel to the furnace and a pump for circulating a small portion of the melt from the furnace through the vessel for dissolution of the alloyant into that portion.

Abstract: A forehearth having a delivery channel 2 for a molten liquid (e.g. glass) 1, provided with a channel ceiling 11 of an insulating refractory ceramic fibre material and with electrical heating means 6, is capable of greatly increased efficiency in energy usage relative to conventional gas-fired forehearths.

Abstract: A method and an apparatus for melting a metallic material in the form of a pile of elongate metal ingots, wherein the ingot pile are pre-heated in a horizontal pre-heating chamber while the pile is moved from its one end to the other end, and the pre-heated pile at the other end is pushed into a melting chamber which communicates with the pre-heating chamber and extends vertically downwardly from the other end of the pre-heating chamber, whereby the pile is turned sideways before falling down into the melting chamber, with a result of collapse of the pile into the individual metal ingots in the melting chamber.

Abstract: A furnace for providing a source of molten aluminum or other metal includes a main chamber and a sweat chamber, the floor of which constitutes a sweat hearth on which ingots or sows are placed. A division wall separates the sweat chamber from the main chamber, and this wall contains ports located at the level of sweat hearth for providing communication between the two chambers. Each chamber, moreover, contains its own set of burners and has a discharge stack leading away from it. Each stack in turn has a refractory damper in it. The burners within the main chamber maintain the bath in a molten condition, and when these burners are in operation, the damper in the stack leading from the main chamber is closed, while the damper in the stack leading from the sweat chamber is open. Thus, the hot gases flow through the ports in the division wall and thence through the sweat chamber to the stack leading from that chamber. The hot gases preheat the sows.

Abstract: The combination of an electric furnace and a slag retaining pouring spout thereon in registry with a modified tap hole is disclosed. The tap hole located in one end of the electric furnace communicates with the interior thereof and the slag retaining pouring spout is positioned on the electric furnace and in communication with the tap hole. The slag retaining pouring spout is angled upwardly and outwardly with respect to the tap hole and positioned above of the molten metal and slag in the operating electric furnace and receives molten metal from the electric furance when the same is tilted to pour the molten metal through the tap hole. The slag retaining pouring spout has a secondary tap hole therein normally closed with a consumable plug during the operation of the electric furnace and the early tap of the molten metal therefrom into the slag retaining pouring spout.

Abstract: There is disclosed a plasma melting furnace through the side wall of whose cylindrical furnace body a plurality of downwardly directed plasma burners are guided, whose mouths project into the furnace interior. In order to avoid several rechargings, which has been common so far, in particular with scrap of low apparent density, and to be able to charge continuously, without endangering the plasma burners by electric flashovers between parts of the charge material and the burner mouths or falling-down materials and by maintaining the inert gas atmosphere within the furnace, the cover of the furnace interior comprises a shoulder-likely re-entering part projecting upwardly. This part is closeable by a lid and delimits a central charging opening whose diameter is smaller than the diameter of the circle on which the mouths of the plasma burners are arranged.

Abstract: In a process for the direct production of sponge iron particles and liquid crude iron from iron ore in lump form, which is reduced in a direct reduction unit and fed in a hot condition to a melting gasifier, the sponge iron particles which are discharged from the direct reduction unit are separated into a fine grain fraction and a coarse grain fraction, and only the fine grain fraction is fed to the melting gasifier. That ensures economy of operation, without an excess of gas.

Abstract: A composite material made of a matrix of a first metal and reinforcing first particles with average particle diameter less than or equal to about ten microns dispersed in the first metal matrix, with the reinforcing first particles each having a composite structure, being made up of a plurality of fine second particles of a ceramic made by reacting together a second metal and a gas and being combined with one another by a matrix of a third metal.

Abstract: Fine powder of a metal is made by vaporizing the metal in a vaporization chamber, mixing the metallic vapor with an inert carrier gas, and then adiabatically expanding the mixture through a nozzle, which preferably is a convergent-divergent nozzle. A jet flow from the nozzle is very rapidly cooled by this adiabatic expansion, which quickly condenses the metal vapor in the jet flow into very fine particles. Optionally the jet flow is directed against a metal powder collecting means, which may be a collection plate, but preferably is a bath of oil which entrains the particles and keeps them from agglomerating together by partially neutralizing their surface activity. Thus fine metal powder with particle diameters of the order of a few hundreds of angstroms can be economically produced.

Abstract: Fine powder of an alloy of two or more metals is made by vaporizing each of these metals in its own vaporization chamber, mixing each of the metallic vapors with an inert carrier gas, and then adiabatically expanding each of the mixture gases through its own nozzle, which preferably is a convergent-divergent nozzle. Jet flows from the nozzles are collided together, after having been very rapidly cooled by this adiabatic expansion, and thereby the metal vapors in the jet flows are quickly condensed into very fine alloy particles. Optionally the combined flows from the jets are directed against an alloy powder collecting means, which may be a collection plate, but preferably is a bath of oil which entrains the alloy particles and keeps them from agglomerating together by partially neutralizing their surface activity. Thus fine alloy powder with particle diameters of the order of a few hundreds of angstroms can be economically produced.

Abstract: A method of charging relatively large briquettes of metal scrap to a melting system at a substantially constant feed rate is disclosed. The method comprises providing a pumping bay, a charging and melting bay, and a molten metal furnace from which molten metal is recirculated from the furnace through the pumping bay to the charging and melting bay. The briquettes are transferred onto a first conveyor adapted to store and convey a controlled weight of briquettes to a second conveyor. The briquettes are conveyed from the first conveyor to a second conveyor mounted on load cells which intermittently stops the first conveyor to maintain a controlled weight in the second conveyor. The briquettes are transferred from the second conveyor to a third conveyor where they are aligned and accumulated. The briquettes are then discharged individually at a substantially constant rate into the melting bay.