Reduction In Molten State Patents (Class 75/500)
  • Patent number: 6409790
    Abstract: An energy efficient, coal-based method and apparatus that are environmentally friendly which produce under pressure metallized/carbon product and molten metal directly from abundant coal or other carbonaceous material, and low cost fines (or ore concentrate) wherein the metal is devoid of gangue material and possesses the inherent advantage of retaining the heat for subsequent processing. This method and apparatus which are modular and highly integrated significantly reduce capital and operating costs; they also provide the capability selective placement of the reductant for the delivery of high levels of thermal energy input which leads to ease of desulflurization and high productivity. The technology herein disclosed is entirely closed and is applicable to various ores including ferrous and non-ferrous.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: June 25, 2002
    Assignee: Calderon Energy Company of Bowling Green, Inc.
    Inventors: Albert Calderon, Terry James Laubis
  • Patent number: 6402808
    Abstract: A process for direct smelting a metalliferous feed material is disclosed. Char and fuel gas are produced by pre-treating coal with an oxygen-containing gas. The fuel gas is used to heat an oxygen-containing gas and/or to produce an oxygen-containing gas in an oxygen plant. Metalliferous feed material, char, and the oxygen-containing gas are injected into a direct smelting vessel, and the metalliferous feed material is smelted to molten metal in the direct smelting vessel using the char as a source of energy and as a reductant.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: June 11, 2002
    Assignee: Technological Resources Pty. Ltd.
    Inventor: Rodney James Dry
  • Patent number: 6379424
    Abstract: A vessel which produces metal from a feed material by direct smelting is disclosed. The vessel contains a molten bath having a metal layer (15) and a slag layer (16) on the metal layer and a gas continuous space (31) above the slag layer. The vessel includes one or more lances/tuyeres (13) extending downwardly into the vessel and injecting an oxygen-containing gas into the vessel and injecting an oxygen-containing bas into the vessel above the metal and slag layer. The vessel includes a plurality of pairs of lances/tuyeres (11) extending downwardly and inwardly into the vessel and injecting feed material with a carrier gas into the molten bath so as to penetrate the metal layer and generate a bath-derived gas flow which carries molten material upwardly. The pairs of lances/tuyeres are spaced around the circumference of the vessel with one lance/tuyere of each pair injecting metalliferous feed material, at a temperature of at least 200° C.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: April 30, 2002
    Assignee: Technological Resources Pty. Ltd.
    Inventor: Rodney James Dry
  • Patent number: 6379422
    Abstract: A process for direct smelting metalliferous feed material is disclosed. Iron oxides are partially reduced in a solid state in a pre-reduction vessel. The partially reduced iron oxides are smelted to molten iron in a direct smelting vessel which contains a molten bath of iron and slag and is supplied with a solid carbonaceous material as a source of reductant and energy and with an oxygen-containing gas for post-combusting carbon monoxide and hydrogen generated in the vessel. The direct smelting step generates an off-gas that contains sulphur and the off-gas is released from the direct smelting vessel. Part only of the off-gas released from the direct smelting vessel is used in the pre-reduction step to pre-reduce iron oxides in the pre-reduction vessel. Part only of the off-gas is used in the pre-reduction step in order to control the amount of sulphur that is returned with the partially reduced iron oxides to the direct smelting vessel.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: April 30, 2002
    Assignee: Technological Resources Pty. Ltd.
    Inventor: Rodney James Dry
  • Patent number: 6368548
    Abstract: A direct smelting process for producing metals from metalliferous feed material is disclosed. The process includes forming a molten bath having a metal layer and a slag layer on the metal layer and smelting injected metalliferous feed material in the metal layer. The process also includes generating an upward gas flow from the metal layer which entrains molten material that is in the metal layer and carries the molten material into the slay layer and forms a region of turbulence at least at the interface of the slag layer and the metal layer. The process also includes injecting a gas into the slag layer via a plurality of lances/tuyeres and generating turbulence in an upper region of the slag layer and projecting splashes, droplets and streams of molten material from the slag layer into a top space of the vessel that is above the slag layer.
    Type: Grant
    Filed: June 2, 2000
    Date of Patent: April 9, 2002
    Assignee: Technological Resources Pty. Ltd.
    Inventor: John Alexander Innes
  • Patent number: 6364929
    Abstract: The invention relates to a method for processing steel slags and iron carriers such as, e.g., electric furnace slags, converter slags, fine ores, dusts from the production of steel and millscale, for recovering pig iron and environmentally safe slags. A molten slag bath and a molten iron bath are used at a volume ratio of between 0.5:1 and 1.5:1 and carbon carriers are introduced into the bath and hot air is top-blown. From the starting slags and iron carriers, a mixed slag having a basicity CaO/SiO2 of between 1.2 and 2.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: April 2, 2002
    Assignee: “Holderbank” Financière Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6332911
    Abstract: In a method for the production of liquid metal, in particular liquid pig iron (9) or liquid steel pre-products, from metal carriers, in particular partially reduced or reduced sponge iron (3), in a melter gasifier (1) in which with supply of a carbon-containing material at least partially formed of fine coal (16) and coal dust (13) and with supply of oxygen or oxygen-containing gas the metal carriers are melted in a bed (4) of the carbon-containing material at the simultaneous formation of a reducing gas, optionally upon previous final reduction, fine coal (16) and coal dust (13) which are being charged, are mixed with bitumen (20) in the hot state, after undergoing a drying operation, and subsequently are cold-briquetted, and the briquettes (25) thus formed are charged to the melter gasifier (1) in the cold state and in the melter gasifier (1) are subjected to shock-heating.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: December 25, 2001
    Assignee: Deutsche Voest-Alpine Industrieanlagenbau GmbH
    Inventors: Günter Schrey, Parviz Zahedi
  • Publication number: 20010052273
    Abstract: The present invention is an apparatus and method for the direct reduction of iron oxide utilizing a rotary hearth furnace to form a high purity carbon-containing iron metal button. The hearth layer may be a refractory or a vitreous hearth layer of iron oxide, carbon, and silica compounds. Additionally, coating materials may be introduced onto the refractory or vitreous hearth layer before iron oxide ore and carbon materials are added, with the coating materials preventing attack of the molten iron on the hearth layer. The coating materials may include compounds of carbon, iron oxide, silicon oxide, magnesium oxide, and/or aluminum oxide. The coating materials may be placed as a solid or a slurry on the hearth layer and heated, which provides a protective layer onto which the iron oxide ores and carbon materials are placed. The iron oxide is reduced and forms molten globules of high purity iron and residual carbon, which remain separate from the hearth layer.
    Type: Application
    Filed: March 12, 1999
    Publication date: December 20, 2001
    Inventors: DAVID C. MEISSNER, GLENN E. HOFFMAN, KYLE J. SHOOP, TAKUYA NEGAMI, AKIRA URAGAMI, YASHUHIRO TANIGAKI, SHUZO ITO, ISAO KOBAYASHI, OSAMU TSUGE, KOJI TOKUDA, SHOICHI KIKUCHI
  • Patent number: 6289034
    Abstract: A process for producing metals from a metalliferous feed material in an electric furnace is disclosed. The process includes the steps of forming a molten bath having a metal layer and a slag layer on the metal layer in the furnace and supplying electrical energy to the furnace and converting the electrical energy to thermal energy and thereby contributing to the heat input requirements of the process. The process also includes injecting a carrier gas and a solid carbonaceous material into the molten bath via one or more than one solids injection lance/tuyere and causing molten material to be projected from the molten bath as splashes, droplets, and streams into a space above a nominal quiescent surface of the molten bath and forming a transition zone.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: September 11, 2001
    Assignee: Technologies Resources Pty. Ltd.
    Inventor: Cecil Peter Bates
  • Patent number: 6287363
    Abstract: In a method of effectively utilizing dusts incurring in the reduction of iron ore by means of a reducing gas and separated on that occasion in a scrubber in the form of sludges, the sludges at first are dehydrated and are used as starting materials for the production of cement (FIG. 1).
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: September 11, 2001
    Assignee: Deutsche Voest-Alpine Industrienalagenbau GmbH
    Inventors: Herbert Grünbacher, Günter Schrey, Franz Zettl, Stefan Zettl
  • Patent number: 6277172
    Abstract: In a method of charging metal carriers which contain a portion of fines and are at least partially reduced and carbon carriers to a melter gasifier (10) in which a melt-down gasifying zone (11) is maintained, the metal carriers and the carbon carriers are fed into the melter gasifier (10) above the level of the melt-down gasifying zone (11) and descend to the melt-down gasifying zone (11) and travel through the same forming a metal melt and producing a reducing gas by coal gasification. In order to prevent a partial discharge of the metal carriers from the melter gasifier (10) during the charging of the same and to be able to achieve uniform distribution of the carbon carriers and the metal carriers, both the carbon carriers and the metal carriers are introduced into the melter gasifier centrally above the melt-down gasifying zone (11), preferably gravitationally, with a central strand (32) of metal carriers being formed which is peripherally surrounded by a jacket strand (37) formed by the carbon carriers.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: August 21, 2001
    Assignees: Voest Alpine Industrieanlagenbau GmbH, Pohang Iron & Steel Co. Ltd., Research Institute of Industrial Science & Technology
    Inventors: Leopold Werner Kepplinger, Felix Wallner, Johannes-Leopold Schenk
  • Patent number: 6273934
    Abstract: A method of producing metals and metal alloys from metal oxides is disclosed. The method comprises the steps of partially pre-reducing the metal oxides to a pre-reduction degree of at least 60% in one or more pre-reduction stages. Thereafter, the method comprises completely reducing the metal oxides and melting the metal in a smelt reduction stage. The method is further characterized by carrying out at least one of the pre-reduction stages with one or more of natural gas, reformed natural gas, and partially reformed natural gas as a source of reductant.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: August 14, 2001
    Assignee: Technological Resouces Pty. Ltd.
    Inventor: Rodney James Dry
  • Patent number: 6273933
    Abstract: According to a process for injecting metal-oxide-containing fine particles into a reducing gas, a central material stream formed by the fine particles and a carrier gas is introduced into the reducing gas and at least one gas stream formed by a secondary gas is directed against the material stream to ensure an optimum contact of the fine particles with the reducing gas, the gas stream atomizing the material stream and the fine particles being evenly distributed within the reducing gas.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: August 14, 2001
    Assignees: Voest - Alphini Industrieanlagenbau GmbH, Pohang Iron & Steel Co. LTD, Research Institute of Industrial Science & Technology
    Inventors: Leopold Werner Kepplinger, Michael Nagl, Franz Hauzenberger, Bernhard Rinner, Felix Wallner, Peter Brandl, Udo Gennari, Johannes Schenk
  • Patent number: 6264724
    Abstract: A plant for producing sponge metal, in particular sponge iron, from charging materials consisting of metal ore or iron ore respectively, preferably in lumps and/or pellets, and optionally fluxes, comprising at least one first gas source (1, 3) dispensing a CO— and H2- containing feedgas, a CO2 elimination plant (17, 17′) and optionally a heating means (22, 25) for the feedgas from the first gas source (1, 3) is provided with a reduction reaction (20) which forms a further gas source for a CO— and H2-containing feedgas and serves for receiving metal ore, a reducing-gas feed duct (19) leading to this reduction reactor (20) and an export-gas discharge duct (31) from said further reduction reactor (20), wherein a conveying duct (30) for at least a portion of the export gas formed in the reduction reactor (20) and serving as a feedgas is flow-connected with the reducing-gas feed duct (19) of the reduction reactor (20) via a CO2 elimination plant and optionally a heating means.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: July 24, 2001
    Assignee: Voest-Alpine Industrieanlagenbau GmbH
    Inventors: Gerald Rosenfellner, Jörg Diehl
  • Patent number: 6261340
    Abstract: In a method of converting slags derived from nonferrous metallurgy, in particular primary and secondary Ni and Cu metallurgical slags, while recovering and/or enriching the nonferrous metals and forming synthetic puzzolans, the molten oxidic slags are reduced with gases containing H2 and CO such as, e.g., cracked gas in a first reduction stage above a metal bath containing Cu and/or Ni and optionally Co. The redox potential of the CO/H2 mixture is reduced by adding 10 to 40% by volume H2O vapor and/or CO2 in order to hold off the reduction of Fe oxides. Subsequently, the remaining slag free of Cu and Ni is further reduced above an iron bath while using carbon in order to reduce the portion of Fe oxides so as to produce a slag free of Fe and nonferrous heavy metals.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: July 17, 2001
    Assignee: “Holderbank” Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6258148
    Abstract: In a method of charging metal carriers which contain a portion of fines and are at least partially reduced to a melter gasifier in which a melt-down gasifying zone formed by a bed is maintained, the metal carriers and carbon carriers are fed into the melter gasifier above the level of the melt-down gasifying zone. The metal carriers descend to the melt-down gasifying zone and travel through the same forming a metal melt and producing a reducing gas by coal gasification.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: July 10, 2001
    Assignees: Voest-Alpine Industrieanlagenbau GmbH, Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology, Incorporated Foundation
    Inventors: Udo Gennari, Johannes-Leopold Schenk
  • Patent number: 6251162
    Abstract: In a method for producing liquid pig iron or liquid steel pre-products from charging substances comprising iron ore, preferably in lumps or pellets, and optionally fluxes. The charging substances are directly reduced to sponge iron in a reduction zone (12) and the sponge iron is melted in a melt-down gasifying zone (8) under the supply of carbon carriers and oxygen-containing gas. CO-and H2-containing gas is introduced into the reduction zone (12) and is reacted there. An export gas is withdrawn and conducted to a consumer (20). The export gas is subjected to CO2 removal or partial combustion and the resulting gas with CO2 is introduced back into the reduction process. This is done to keep down the carbon carriers having high portion of Cfix as well as consumption of O2.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: June 26, 2001
    Assignee: Deutsche Voest-Alpine Industrieanlagenbau GmbH
    Inventors: Ernst Eichberger, Günter Schrey, Franz Reufer, Jörg Diehl, Gerald Rosenfellner
  • Patent number: 6241797
    Abstract: There is disclosed a process for reducing oxidic slags or combustion residues above a metal bath. The metal bath is formed of an iron alloy containing metals nobler than iron and whose redox potential is adjusted such FeO is reduced to Fe not at all or only partially.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: June 5, 2001
    Assignee: “Holderbank” Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6238453
    Abstract: A process for producing stainless steels, particularly special steels containing chromium and chromium-nickel, in a smelting arrangement having at least two vessels, for supplying a steel foundry. A charge having mostly iron-containing raw scrap materials and partially carbon-containing alloy carriers is melted in a first vessel. At a temperature of 1460° C., the melt is decarburized by the injection of oxygen so as to reduce the carbon content to less than 0.3%. The melt is heated to a tapping temperature of between 1620° C. to 1720° C. and the carbon content is subsequently reduced to 0.1%. A second charge is melted in a second vessel simultaneously with the decarburizing of the first charge in the first vessel.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: May 29, 2001
    Assignee: Mannesmann AG
    Inventors: Lutz Rose, Hartmut Vorwerk, Horst Kappes, Klaus Ulrich
  • Patent number: 6214085
    Abstract: This invention relates to making steel directly from ore concentrate and non-coking coal to which flux material is added. The method eliminates numerous steps by reducing the ore with the coal in a sealed chamber and under pressure termed “carbotreating” to make a fluxed iron/carbon product which after crushing, is injected while hot into a melting furnace. The hot product is melted with oxygen under reducing conditions using excess carbon from the coal to make a carburized molten iron and a slag low in FeO termed “oxymelting”. After the tapping of the slag, the carburized molten iron to which flux material is added, is blown with oxygen to make steel, CO, and a slag high in FeO termed “decarburizing”. The steel is tapped while the slag is retained in the furnace. All of the above steps are carried out in an efficient and environmentally sound manner which render the art of steelmaking significantly more economical than conventionally practiced.
    Type: Grant
    Filed: February 1, 1999
    Date of Patent: April 10, 2001
    Assignee: Calderon Energy Company of Bowling Green, Inc.
    Inventors: Albert Calderon, Terry James Laubis
  • Patent number: 6214087
    Abstract: A method for producing solid metal product is disclosed including the steps of providing carbon and metal bearing compounds in compacts, coating the compacts with treatment materials, encapsulating the compacts with carbonaceous containing materials to form a residual layer, and treating the residual layer before introduction of the compacts into a furnace. The compacts contain carbon containing metal bearing compounds, and are coated with mixtures of carbonaceous materials dispersed within a binder material such as a viscous liquid, molasses, alcohol, or fuel oil. The coated compacts are treated to form a hardened outer residual layer. The outer residual layer provides for a sacrificial outer coating on the compacts that reacts with any oxidizing gaseous components within the furnace, while the carbon containing metal bearing compounds within the compacts are heated and metallized inside the compounds.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: April 10, 2001
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, David C. Meissner, Kyle J. Shoop
  • Patent number: 6210462
    Abstract: A method of making metallic iron includes heating a mixed powder containing iron oxide and a carbonaceous reducing agent on a hearth to reduce the iron oxide and melt the reduced iron. Preliminary molding of the mixed powder starting material into pellets is not required. The resulting metallic iron contains extremely low concentrations of slag ingredients, even when the mixed powder starting material contains only low concentrations of iron oxide.
    Type: Grant
    Filed: October 22, 1998
    Date of Patent: April 3, 2001
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Shoichi Kikuchi, Akira Uragami, Isao Kobayashi, Yasuhiro Tanigaki, Eiichi Ito, Koji Tokuda, Osamu Tsuchiya, Shuzo Ito
  • Patent number: 6203595
    Abstract: In this process for working up RESH or shredder light fractions, the RESH or shredder light fractions are charged into a fluidized bed gasifier. Hot wind or combustion offgases having a temperature above 450° C. are blown into the fluidized bed through nozzles while forming a counterflow grinding space. CaCO3 is introduced into the fluidized bed and calcined in the grinding space to effect disintegration.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: March 20, 2001
    Assignee: “Holderbank” Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6146441
    Abstract: A process for at least partially reducing iron oxides comprises forming a bed of reactants on a hearth of a rotary hearth furnace, the reactants comprising (a) mixture of iron ore fines and particulate carbonaceous material and/or (b) micro-agglomerates of iron ore fines and particulate carbonaceous material. The mixture and/or the micro-agglomerates are heated in the rotary hearth furnace to at least reduce the iron oxides. The "micro-agglomerates" are agglomerates that are less than 1400 microns (and preferably more than 500 microns) in diameter. The at least partially reduced product is preferably used in the production of metallic iron. An apparatus for at least partially reducing iron oxides is also claimed. The process permits operation of the rotary hearth furnace without requiring pelletisation of iron oxides fines and coal.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: November 14, 2000
    Assignee: Technological Resources Pty Ltd
    Inventor: John Alexander Innes
  • Patent number: 6143054
    Abstract: A molten bath-based direct smelting process for producing metals from metal oxides (including partially reduced metal oxides) is disclosed. The process includes causing upward movement of splashes, droplets, and streams of molten material from a metal layer (15) of the molten bath which:(i) promotes strong mixing of metal in a slag layer (16) of the molten bath so that the slag layer (16) is maintained in a strongly reducing condition leading to FeO levels below 8 wt % based on the total weight of the slag in the slag layer (16); and(ii) extends into a space above a nominal quiescent surface of the molten bath to form a transition zone (23).
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: November 7, 2000
    Assignee: Technological Resources Pty Ltd.
    Inventor: Rodney James Dry
  • Patent number: 6126718
    Abstract: Producing reduced metal by charging and stacking a raw material containing a metal-containing material and a solid reducing material on a horizontally moving hearth of a traveling hearth furnace, by disposing a solid reducing material layer on the hearth, forming concave portions at the solid reducing material surface, stacking the raw material on the surface of the solid reducing material layer, reducing raw material by at least once heating and melting the material on the hearth to separate metal and gangue and ash ingredients, and discharging metal from the hearth.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: October 3, 2000
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoshitaka Sawa, Tetsuya Yamamoto, Kanji Takeda, Hiroshi Itaya
  • Patent number: 6102982
    Abstract: A method for recovering zinc oxide comprises the steps of: agglomerating a dust; charging the agglomerate to a molten iron in a melting furnace; collecting a dust generated from the melting furnace; recycling a part of the collected dust and recovering another part of the collected dust. An apparatus for recovering zinc oxide comprises: an agglomeration unit for agglomerating a dust containing iron oxide and zinc oxide; a melting furnace for accepting the agglomerate and for holding the molten iron for reducing the dust; and at least two units of dust collector for collecting the dust containing zinc oxide generated from the melting furnace.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: August 15, 2000
    Assignee: NKK Corporation
    Inventors: Shinichi Isozaki, Noboru Sato, Yoshihito Iwata, Noboru Sakamoto
  • Patent number: 6068677
    Abstract: The method for processing waste or waste fractions, such as, for example, household refuse, car shredder light fractions or the like, provides for pyrolysis, gasification and/or combustion, whereupon the residues are melted under reducing conditions. The reduced portions are then are subjected to a stepwise oxidation, with chromium being quantitatively separated in a first oxidation stage. After this, a calcium ferrite slag is formed by further oxidation, whereupon the remaining metal bath is further processed in order to recover nonferrous heavy metals.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: May 30, 2000
    Assignee: "Holderbank" Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6039787
    Abstract: In a process for working up combustion residues and slags from waste incineration plants or steel works slags, the slag is charged at a slag layer height of above 1.2 m into a converter (1), in which the molten slag is reacted with a metal bath (4) through which oxygen is blown. The oxygen is introduced into the bath (4) for cooling the submerged tuyeres (7, 8) in the form of air or along with CO.sub.2 or water vapor.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: March 21, 2000
    Assignee: "Holderbahk" Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 6022396
    Abstract: The residues arising from industrial processes and from waste disposal which are polluted with heavy metals and/or heavy metal compounds, are subjected to a two-stage reduction process with formation of re-usable metal-containing and silicon-containing alloys. In a first reduction stage, using carbon or carbon-generating means as the reduction means, the compounds of silicon and metals are reduced, which have a standard potential which is greater than that of silicon. Following separation of the reduced metals, the residue obtained, which contains aluminum in oxidized form, is subsequently converted to a salt melt and this salt melt is subjected to a second reduction stage of a fused salt electrolysis, yielding an aluminum and silicon melt. The process is particularly suitable for filter residues from waste incineration plants.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: February 8, 2000
    Assignee: Refista Recycling AG
    Inventor: Markus Grauwiller
  • Patent number: 5938815
    Abstract: An iron ore refining method in which a secondary reactor is employed for partly reducing iron ore and partly oxidizing a carbon containing substance to form partly reduced secondary iron ore, the coal char and a calorific containing carbon dioxide and carbon monoxide in a ratio of no less than about 0.25. The calorific gas is separated from the partly reduced secondary iron ore and the coal char and the resulting heated solids are introduced into the primary reactor without substantial cooling. All or part of the iron product is formed from the partly reduced iron ore produced in the primary reactor. Since the secondary reactor operates at a lower temperature than the primary reactor, part of the iron product is processed at a lower temperature to reduce oxygen requirements for the refining and to increase thermal efficiency.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: August 17, 1999
    Assignee: The BOC Company, Inc.
    Inventor: Donald Prentice Satchell, Jr.
  • Patent number: 5865872
    Abstract: A method of recovering metals and producing a secondary slag from base metal smelter slag produced by a copper or nickel smelter includes mixing the smelter slag with at least one reducing agent selected from the group consisting of carbon, calcium carbide, ferrosilicon and aluminum, said carbon and calcium carbide (if present) being from about 1% to about 40% by weight of the slag and said aluminum (if present) being from about 2% to about 35% by weight of the slag and with from zero to about 70% calcium oxide by weight of the slag, heating the mixture aluminothermically if Al is present as reducing agent above the melting point to reduce the smelter slag to a metal alloy containing iron and possibly silicon and aluminum, depending on the quantity of aluminum added to the smelter slag, and heavy metals such as copper, nickel and cobalt which were in the smelter slag and thereby also producing a secondary slag containing at least one compound selected from the group consisting of calcium silicate, calcium alu
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: February 2, 1999
    Assignee: Fenicem Minerals Inc.
    Inventors: David Krofchak, Werner Dresler
  • Patent number: 5855645
    Abstract: A method for producing a more concentrated iron product from an industrial waste materials stream comprising iron and non-iron constituents such as EAF and basic oxygen furnace dust generally comprising the steps of compacting or briquetting the waste materials stream, roasting the waste materials stream at temperatures above about 980.degree. C. to convert the iron compounds to direct reduced iron, crushing the roasted waste materials stream, separating the iron compounds contained in the waste materials stream by magnetic separation or flotation, and providing the iron compounds back to the EAF or basic oxygen furnace.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: January 5, 1999
    Assignee: Metals Recycling Technologies Corp.
    Inventors: Allan S. Myerson, Charles W. Sanzenbacher, Peter Robinson, Charles A. Burrows, Paul R. DiBella
  • Patent number: 5800592
    Abstract: A process for producing molten pig iron uses direct reduction of iron ore in a pre-reduction stage followed by a final reduction stage.In the pre-reduction stage iron ore is pre-reduced in a melting cyclone by means of a reducing process gas originating from the final reduction stage. A post-combustion occurs in the reducing process gas in the melting cyclone so that said iron ore in said melting cyclone is at least partly melted. The partly melted iron ore passes downwardly into a metallurgical vessel situated beneath the cyclone in which the final reduction takes place by supply of coal and oxygen, thereby forming a reducing process gas. A partial post-combustion occurs in the reducing process gas in the metallurgical vessel by means of said oxygen supplied thereto. The post-combustion ratio of the gas on exiting the metallurgical vessel is not more than 0.55.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: September 1, 1998
    Assignee: Hoogovens Staal BV
    Inventors: Huibert W. den Hartog, Hendrikus K. A. Meijer
  • Patent number: 5776226
    Abstract: A method for working up refuse or metal-oxide-containing refuse incineration residues or metallurgical residues includes an at least partial oxidation in a meltdown oxidizing reactor followed by a two-stage reduction. The first reduction stage is effected in an iron bath reactor in which iron oxides are not yet reduced. In the second reduction stage also iron oxides are reduced in an iron bath calciner, a pig iron bath being obtained. The metal bath discharged from the iron bath reactor reaches a segregation mold, from which crude bronze can be drawn off.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: July 7, 1998
    Assignee: "Holderbank" Financiere Glarus AG
    Inventor: Alfred Edlinger
  • Patent number: 5753006
    Abstract: Disclosed is a method for the aluminothermal production of molten steel for the aluminothermal welding of workpieces, wherein the aluminothermal reaction is carried out in a crucible made of porous or hollow spherical .alpha.-Al.sub.2 O.sub.3 with a density of 0.8-3.0 g/cm.sup.3 and a bulk density of 0.3-1.8 g/cm.sup.3.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: May 19, 1998
    Assignee: Elektro-Thermit GmbH
    Inventors: Horst Eggert, Michael Steinhorst
  • Patent number: 5746804
    Abstract: An apparatus for and a method of melting fine particles containing carbon, capable of uniformly burning and melting the fine particles throughout the entire zone of the combustion flame. The apparatus includes a triple tube structure including an inner oxygen feeding section having an oxygen inlet tube provided with an oxygen feeding passage, a particle feeding section arranged surrounding the inner oxygen feeding section, comprising a particle inlet tube, a feeding tube and a feeding passage, and an outer oxygen feeding section arranged surrounding the particle feeding section, comprising an outer oxygen inlet tube, a feeding tube and a feeding passage. The front ends of the inner oxygen feeding tube, particle feeding tube and outer oxygen feeding tube constitute a nozzle which serves to inject the fine particles fed through the particle feeding tube together with air and/or oxygen flows respectively fed through the inner and outer oxygen feeding tubes to be burned and melted.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: May 5, 1998
    Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology, Voest-Alpine Industrieanlagenbau GmbH
    Inventors: Sang Hoon Joo, Dong Joon Min, Myoung Kyun Shin
  • Patent number: 5741349
    Abstract: A refractory-lined high temperature reaction vessel comprises a refractory ring lining constructed of refractory brick, a cooler, and a heat transfer medium disposed between the refractory ring lining and the cooler. The refractory brick comprises magnesia (MgO) and graphite. The heat transfer medium contacts the refractory brick and a cooling surface of the cooler, and is composed of a material that accommodates relative movement between the refractory brick and the cooler. The brick is manufactured such that the graphite has an orientation providing a high thermal conductivity in the lengthwise direction through the brick that is higher than the thermal conductivity in directions perpendicular to the lengthwise direction. The graphite preferably is flake graphite, in the range of about 10 to 20 wt %, and has a size distribution selected to provide maximum brick density.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: April 21, 1998
    Assignee: Steel Technology Corporation
    Inventors: David H. Hubble, Klaus H. Ulrich
  • Patent number: 5717149
    Abstract: A method and apparatus producing halogenated products from metal halide feeds. In one embodiment, uranium hexafluoride is treated by separating fluorine from the metal of the uranium hexafluoride. Uranium hexafluoride is introduced into a molten metal bath under conditions whereby the uranium hexafluoride in the presence of hydrogen and oxygen can react to form a uranium dioxide and anhydrous hydrogen fluoride. The anhydrous hydrogen fluoride is removed from the molten metal bath as a gas stream and the uranium dioxide is discharged as a ceramic phase.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 10, 1998
    Assignee: Molten Metal Technology, Inc.
    Inventors: Christopher J. Nagel, Robert D. Bach, Michael J. Stephenson, James E. Johnston
  • Patent number: 5695543
    Abstract: A method and system for recovering metal from steel waste products is disclosed. This method and system works on such hazardous and/or toxic wastes as mill scale, flue dust and slag. This method and system operates by mixing the steel waste produce with a flux composition and then melting the mix in a single phase two electrode electric arc furnace. Once the mixture is melted by the heat from the electrodes, the electro-magnetic field induced in the melted mixture serves to enhance the recovery from the steel waste product of useful steel material. Furthermore, this method and system provide a cost effective solution to the hazardous waste disposal problems impacting steel refineries around the world and does so in a manner that removes the toxicity of the waste while producing a variety of useful products, including high grade steel and neutralized fill.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: December 9, 1997
    Assignee: D & S Technologies, Inc.
    Inventor: Desmond L. Shields
  • Patent number: 5681367
    Abstract: A method for preparing iron bearing green pellets that can be processed in a rotary hearth furnace without degradation and become self-fluxing sponge iron pellets when charged to a submerged arc furnace operating at a lower temperature than the rotary hearth furnace, to produce hot metal having a carbon content from 1% to about 5%.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: October 28, 1997
    Assignee: USX Engineers & Consultants, Inc.
    Inventor: Phillip B. Hunter
  • Patent number: 5632800
    Abstract: A process for improving the rate of metal production and FeO utilization in a steelmaking process or a process combining iron-making and steelmaking in a single reactor that uses or generates Fe-C metal alloy droplets submerged in an FeO-containing slag. The process involves discharging a charge build-up (electron accumulation) in the slag at the slag-metal alloy interface by means of an electron conductor connected between the metal alloy droplets and a gas at a gas-slag interface, said gas having an oxygen partial pressure of at least about 0.01 atmosphere.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: May 27, 1997
    Assignee: Massachusetts Institute of Technology
    Inventors: Uday B. Pal, Donald R. Sadoway
  • Patent number: 5626646
    Abstract: A method of recovering metals and producing a secondary slag from base metal smelter slag produced by a copper or nickel smelter includes mixing the smelter slag with at least one reducing agent selected from the group consisting of carbon and aluminum, said carbon (if present) being from about 1% to about 10% by weight of the slag and said aluminum (if present) being from about 5 to about 30% by weight of the slag, and with from zero to about 60% calcium oxide by weight of the slag. The mixture is heated above the eutectic melting point thereof directly and to ignition temperature aluminothermically (if aluminum is present as reducing agent) to reduce the iron silicate to ferrosilicon containing substantially all the copper, nickel and cobalt which was in the smelter slag and form a secondary slag comprising at least one compound selected from the group consisting of calcium silicate, calcium aluminate and calcium iron aluminum silicate. The ferrosilicon is then separated from the secondary slag.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: May 6, 1997
    Assignee: Fenicem Minerals Inc.
    Inventor: David Krofchak
  • Patent number: 5554207
    Abstract: A process for recovering iron values from waste iron oxide, especially iron oxide dust from steelmaking furnaces, wherein the iron oxide is mixed with a water-insoluble thermoplastic material and heated to melt the plastic to form a binder for the iron oxide particles, and discrete bodies formed of the mixture are returned to a furnace to recover the iron values. The plastic binder is present in an amount sufficient to serve as a reductant to reduce the iron oxide to metallic iron when the plastic is combusted with oxygen in the furnace. The invention also includes the discrete bodies so formed of iron oxide and thermoplastic binder.
    Type: Grant
    Filed: November 25, 1994
    Date of Patent: September 10, 1996
    Assignee: USX Corporation
    Inventors: Eugene A. Bogdan, Alvin A. Terchick
  • Patent number: 5435832
    Abstract: In order to utilise wastes or residues containing iron in the oxide form and/or iron in the metallic form and/or containing carbon (38,25,34), a process is used with which molten pig iron (16) or steel preliminary products can be produced, iron ore (4) being reduced to sponge iron in a direct reduction zone (2), the sponge iron being melted in a melting-gasification zone (15) with the supply of carbon-containing material (29) with gasification of the carbon-containing material (29) to reducing gas, and the reducing gas is fed into the direct reduction zone (2), reacted there and drawn off as top gas.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: July 25, 1995
    Assignee: Deutsche Voest-Alpine
    Inventors: Leopold W. Kepplinger, Gunter Schrey, Gero Tessmer
  • Patent number: 5411572
    Abstract: The invention relates to a method for utilizing zinciferous waste from metal smelters, such as steel smelters, so that the transmission of fluorides to the highly zinciferous secondary dusts is prevented during the treatment of the gas obtained from the waste smelting furnace. Fluorides are extremely harmful for the zinc process, and therefore it is important to prevent them from entering the process. By adjusting, according to the invention, the temperature and composition of the exhaust gases created in the smelting treatment of zinciferous dusts and other waste, the fluorides and the highly zinciferous fraction are obtained in different end products. Other valuable metals are recovered from the metal layer created on the bottom of the furnace.
    Type: Grant
    Filed: January 6, 1994
    Date of Patent: May 2, 1995
    Assignee: Outokumpu Research Oy
    Inventors: Frans H. Tuovinen, Maija-Leena Metsarinta
  • Patent number: 5401295
    Abstract: The invention relates to a method for smelting reduction of metal ores involving a combination process wherein the metal ores are partly reduced in one or more stages and then completely reduced to metal in a melt-down reactor. The combination process comprises at least three process units, and the melt-down reactor forms one process unit. The partial reduction of the metal ores is performed in at least two further process units. A different waste gas is produced in each of these at least three process units.
    Type: Grant
    Filed: March 3, 1993
    Date of Patent: March 28, 1995
    Assignee: Technological Resources Pty. Ltd.
    Inventor: Karl Brotzmann
  • Patent number: 5378260
    Abstract: A process for continuously smelting iron ore by use of coal to yield molten iron or semi-steel is disclosed. The process comprises the steps of establishing a melt covered by slag; inducing the slag and the molten iron to flow countercurrently to one another, toward opposite ends of the smelter; maintaining iron oxide-reducing conditions in that zone of the smelter towards which the slag flows; maintaining carbon-oxidizing conditions in that zone of the smelter towards which the molten iron flows; continuously or semicontinuously tapping the slag from the reducing zone end of the smelter; continuously or semicontinuously tapping the molten iron from the oxidizing zone end of the smelter; and adding to both zones iron ore, coal, oxygen, and flux at addition rates sufficient to keep the molten iron in the reducing zone substantially saturated with carbon, maintain in the slag being tapped an FeO content of about 5 weight percent or less, and maintain in the molten iron being tapped a carbon content of about 0.
    Type: Grant
    Filed: July 26, 1991
    Date of Patent: January 3, 1995
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: James H. Cox, Richard J. Fruehan, John F. Elliott, deceased
  • Patent number: 5364447
    Abstract: A smelting process for blending hazardous and non-hazardous inorganic industrial wastes with carbon or aluminum reducing agents to simultaneously recover metal alloys (reducible metals), metal oxides (volatile reducible metals), carbon dioxide and man-made vitreous fiber (non reducible metals). Wastes including hazardous wastes of U.S. EPA Series D, F, P, K, and U are pulverized and blended with liquids such as water or waste water to produce a homogeneous mass. The mass is formed into briquettes and melted in a cupola or plasma arc furnace in the presence of carbon or aluminum to reduce metals. Other types of furnaces such as an electric arc furnace may be used to avoid the steps of forming and curing briquettes. Reduction is carried out at temperatures between 1660 and 3100 degrees Fahrenheit. Calcium flux from calcium-stabilized wastes enhances mineral wool quality, lowers the sulfur content of metals and raises pH to facilitate metal reduction. Reducible metals are reduced and drawn off into molds.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: November 15, 1994
    Assignee: Enviroscience, Inc.
    Inventors: Carl T. Philipp, Bobby H. Sims
  • Patent number: 5316565
    Abstract: Method and apparatus for reducing the quantity of carbon dioxide emitted to the atmosphere from carbothermic processes producing metals are described. The method involves rejecting carbon from the process system or using carbon as a reagent to be recycled within the boundaries of the process system as a result of reactions of hydrogen with the carbon monoxide produced by the carbothermic process. Examples of the application of the method are given for the production of aluminum and for the production of a portion of the iron content of steel.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: May 31, 1994
    Inventor: Robert M. Kibby