Reduction Patents (Class 75/695)
  • Patent number: 8419824
    Abstract: An object of the present invention is to produce briquettes that have high strength even when the amounts of binder and water used are decreased as much as possible. A method for producing briquettes that achieve this object includes a step of forming primary granules by using a powder containing a metal oxide and at least one of zinc oxide, lead oxide, and titanium oxide and a step of compressing the primary granules still containing the at least one of zinc oxide, lead oxide, and titanium oxide so as to mold the primary granules into secondary granules.
    Type: Grant
    Filed: July 8, 2009
    Date of Patent: April 16, 2013
    Assignee: Kobe Steel, Ltd.
    Inventors: Masahiko Tetsumoto, Yutaka Miyakawa, Noriaki Mizutani
  • Patent number: 8308844
    Abstract: A method of reduction treatment of metal oxides characterized by using as a material a powder containing metal oxides and containing alkali metals and halogen elements and further, in accordance with need, carbon, mixing the material with water to produce a slurry, then dehydrating this and charging the dehydrated material, mixed with another material in accordance with need, into a rotary hearth type reduction furnace for reduction.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: November 13, 2012
    Assignee: Nippon Steel Corporation
    Inventors: Hiroshi Ichikawa, Tetsuharu Ibaraki, Shoji Imura, Hiroshi Oda, Yoichi Abe, Shigeki Takahashi, Nobuyuki Kanemori, Satoshi Suzuki
  • Publication number: 20110154950
    Abstract: Burner assembly for use in industrial heating and melting applications of material susceptible to oxidation at elevated temperatures is comprised of a flow passage of oxidant surrounded by an annular flow passage of fuel whereby the oxidant is substantially contained inside the fuel layer up to at least 5 oxidant nozzle diameters downstream of the burner outlet in order to minimize contact between the oxidant and the furnace load.
    Type: Application
    Filed: July 1, 2010
    Publication date: June 30, 2011
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Jin Cao, Russell James Hewertson, Xiaoyi He
  • Publication number: 20110079109
    Abstract: The present invention relates to a method of operating a converter, in particular a Peirce-Smith converter or a converter with similar design or mode of operation, and to an apparatus, for instance a plant, for carrying out the method. The method comprises the step of: loading the converter with a starting material comprising said metal, the metal in the starting material being chemically bound at least in part to at least one compound substance, in particular sulphur; maintaining a temperature within the converter interior space, which is above the melting temperature of the starting material; and supplying an oxygen-containing process gas into the converter interior space through injection nozzles arranged in the wall of the converter, the gas supplied through the injection nozzles comprising carbon dioxide, preferably very cold, technically pure carbon dioxide, as well as oxygen gas and/or air.
    Type: Application
    Filed: September 1, 2010
    Publication date: April 7, 2011
    Applicant: LINDE AG
    Inventor: Martin Adendorff
  • Patent number: 7819941
    Abstract: The invention relates to a method for reducing and/or refining a metal-containing slag. The aim of the invention is to improve reduction of the slag. For this purpose, calcium carbide (CaC2) is added to the slag as the reducing agent.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: October 26, 2010
    Assignee: SMS Siemag Aktiengesellschaft
    Inventors: Jürgen Kunze, Rolf Degel, Dieter Borgwardt, Andrzej Warczok, Gabriel Angel Riveros Urzua, Marco Antonio Caceres Rivera, Roberto Marcelo Parada Araya
  • Publication number: 20100107821
    Abstract: A swirling column nozzle comprises a nozzle body with an air chamber defined therein; an outlet portion, a feed pipe penetrating through the air chamber and extending to the outlet portion, an oxygen supplying portion disposed on the nozzle body, the outlet portion is formed with a swirling guide part for moving a mixture of the oxygen gas and the concentrate downwardly in the form of a swirling column. Further, a swirling column smelting equipment and a method thereof are disclosed. The air flow moves downwardly in a substantially swirling column, so the chemical reaction path and reaction time are extended remarkably, allowing the reduction of the height of the reaction shaft.
    Type: Application
    Filed: January 28, 2009
    Publication date: May 6, 2010
    Inventors: Jikun Wang, Wenhai Zhang, Ying Dong, Xiaobo Zhang
  • Patent number: 6379421
    Abstract: The present invention relates to a method and apparatus for separating undesired toxic metals, such as Zn, Pb and Cd, from iron-containing materials by: sintering a mixture of such materials (typically including EAF dust and mill scale) with carbonaceous particles to form sturdy sinter lumps; preheating such lumps in a non-reducing atmosphere, if needed, to achieve an elevated temperature generally above the vaporization temperature of the undesired metals, but below the sticking temperature of iron-containing lumps (which is typically below the vaporization temperatures of such undesired metals in their oxide form), feeding the lumps at such elevated temperature into a reduction reactor; flowing hot reducing gas through lumps to volatilize undesired reduced metals and carry the volatilized metals out of reduction reactor leaving the iron-containing lumps largely stripped of the undesired metals and ready for discharge and safe and/or useful disposal or re-use, and finally cooling the off gas from the reactor
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: April 30, 2002
    Assignee: Hylsa S.A. de C.V.
    Inventors: Mario Alberto Salinas-Fernández, Maria Teresa Guerra-Reyes, José Mariá Eloy Aparicio-Arranz, Juan Antonio Villarreal-Treviño, Miguel Angel Pedroza-Contreras
  • Patent number: 6315810
    Abstract: In a process for vitrifying heavy-metal-containing residues having a chlorine content above 10% by mass, in particular from flue gas cleaning, which are melted in a melting furnace, the constituents which cannot be incorporated into the melt are separated in the main furnace into two fractions, the first fraction comprising the readily volatile components and the second fraction comprising the salt-like less volatile components, and the first fraction is evaporated off, conducted out of the furnace together with the exhaust gas and collected as condensate, and the second fraction is separated from the surface of the melt as liquid salt and is discharged.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: November 13, 2001
    Assignee: ABB Research Ltd.
    Inventor: Günter Mechtersheimer
  • Patent number: 6270551
    Abstract: A process for recovering iron from iron-bearing materials including steel mill waste and iron-bearing ores. The process includes the steps of providing a mixture of iron-bearing materials having iron oxides therein and carbonaceous material. Blending with the mixture an organic binder. The mixture is then agglomerated to form green compacts. The green compacts are then loaded into a preheated rotary hearth furnace void of compacts to form a layer of compacts no more than about two compacts high. The green compacts are heated for about 5-12 minutes at a temperature of between about 2200-2500° F. to reduce the compacts and evolve undesirable oxides from the compacts. The reduced compacts are then discharged from the rotary hearth furnace whereupon they are soaked to provide additional time for reaction to achieve 99% or more reduction of the iron oxides. The metallized iron compacts may then be cooled or transported hot to a steel making operation.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: August 7, 2001
    Assignee: Maumee Research & Engineering, Inc.
    Inventors: Franklin G. Rinker, Deane A. Horne, James A. Thornton, Valdis R. Daiga
  • Patent number: 6159268
    Abstract: The invention relates to a process for pyrometallurgical processing, in a furnace chamber, of metal-containing waste which may also contain a quantity of organic material. The process involves a reducing gas being blown with high velocity onto the surface of the smelt in which the metal oxides are present in the molten state, the reducing gas being made by incomplete combustion of a fuel and/or the organic material and an oxygen-containing gas. Additionally, steam and/or an oxygen-rich gas such as almost pure oxygen are injected, roughly parallel to the surface of the smelt, into the oven chamber above said surface. The total amount of oxygen used in the furnace chamber is lower than the amount required stoichiometrically for complete combustion of the organic material together with the fuel.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: December 12, 2000
    Assignee: Droan B.V.
    Inventors: Jan Pieter Lotens, Klaus Jungk
  • Patent number: 6120577
    Abstract: A process of recovering iron values and separating zinc oxides and other contaminants from steel mill waste metal oxides, such as blast furnace dust, BOF dust, mill scale and oily sludges, characterized by iron metallization levels up to 95% or more and zinc oxide removal in excess of 99%, and including the steps of blending the oxides with coke breeze in an amount sufficient to provide a total carbon content of 16% to 22%, the coke breeze having a particle size of 50% or more plus 60 mesh or larger, briquetting the blend to form briquettes having a thickness ranging from 1/2" to 3/4", and firing the briquettes in a rotary hearth furnace to metallize the iron and evolve zinc and other oxide contaminants.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: September 19, 2000
    Assignees: LTV Steel Company, Inc., Maumee Research and Engineering, Inc., USX Corporation
    Inventors: Peter J. Koros, Jagjit S. Bajaj, Valdis R. Daiga, Vishwaprakash S. Hegde
  • Patent number: 6053963
    Abstract: The present invention provides a method for treating rotary slag containing iron and sodium compounds. The method involves treating the slag in a sulfuric acid solution to convert the iron and sodium within the slag to iron sulfate and sodium sulfate. The iron sulfate (along with substantially all of the heavy metal contaminants) forms a precipitate, while the sodium sulfate remains in solution. The precipitate can then be separated from the solution.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: April 25, 2000
    Assignee: GNB Technologies, Inc.
    Inventor: Paul R. Graves, Jr.
  • Patent number: 5944869
    Abstract: An improved method for the recovery of lead from exhausted lead-acid storage batteries, comprising removal from the storage battery of the sulphuric acid solution, the coating element, the separators between the electrodes and the metal part i.e. grids, connectors and poles and milling of the remaining electrode paste of the storage battery to obtain an extremely fine powder (pastel),characterised by the following operations:a) treatment of the resulting powder with an aqueous saline solution, with a pH of between 0 and 8, capable of solubilising Pb (II) sulphate and oxide, leaving Pb (IV) oxide unsolubilised;b) reduction to metal lead of the bivalent lead ion, present in the soluble fraction, using metal iron, preferably in slight excess with respect to the stoichiometric proportions;c) reduction of the tetravalent lead oxide; andd) recovery of the salts used in the process step a) by elimination of the iron sulphate that has formed. FIG.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: August 31, 1999
    Assignees: Ente per le nuove technologie, l'energia e l'ambiente (ENEA), Giovanni Modica
    Inventors: Giovanni Modica, Roberto Nannicini
  • Patent number: 5871561
    Abstract: Dusts containing zinc and/or lead in the form of oxides and one or more reducing agents are mixed with each other before or after being introduced into a heat treatment furnace. The mixture is heated to a given temperature range under a substantial vacuum so that the zinc and/or lead in the form of oxides are reduced to zinc and/or lead in the state of pure metals and evaporated in the furnace. The evaporated zinc and/or lead are introduced into a retrieving container also under a substantial vacuum and at a given temperature where the evaporated zinc and/or lead pure metals are condensed and retrieved.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: February 16, 1999
    Assignees: Toyota Jidosha Kabushiki Kaisha, Aichi Steel Works, Ltd., Toyokin Kabushiki Kaisha
    Inventors: Yuji Okada, Hirokazu Shirakawa, Masamichi Okada, Toshikatsu Hara, Hirohiko Sasamoto, Kazuhiro Suzuki
  • Patent number: 5865875
    Abstract: A process for recovering iron from iron-bearing materials including steel mill waste and iron-bearing ores. The process includes the steps of providing a mixture of iron-bearing materials having iron oxides therein and carbonaceous material. The mixture is agglomerated to form green compacts. The green compacts are then loaded into a preheated rotary hearth furnace void of compacts to form a layer of compacts no more than about two compacts high. The green compacts are heated for about 5 to 12 minutes at a temperature of between about 2200.degree. F. to 2500.degree. F. to reduce the compacts and evolve undesirable oxides from the compacts. The reduced compacts are then discharged from the rotary hearth furnace whereupon they are soaked to provide additional time for reaction to achieve 99% or more reduction of the iron oxides. The metallized iron compacts may then be cooled or transported hot to a steel making operation.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: February 2, 1999
    Assignee: Maumee Research & Engineering, Inc.
    Inventors: Franklin G. Rinker, Deane A. Horne, James Alan Thornton, Valdis R. Daiga
  • Patent number: 5782957
    Abstract: A process for treating iron-bearing material with a carbonaceous material to form a dry mixture, wherein the amount of carbonaceous material added exceeds the stoichiometric amount required to reduce the metal oxide to elemental metal. In one embodiment, the process also includes blending an organic binder with the dry mixture. The dry mixture is agglomerated to bond the dry mixture and form green compacts. The green compacts are loaded into a heated furnace and heated for about 5-12 minutes at a temperature of between about 2100.degree.-2500.degree. F. to reduce the iron oxide containing compacts to compacts containing elemental iron and an excess amount of carbonaceous material wherein the excess amount of carbonaceous material counteracts re-oxidation of the elemental iron. The reduced compacts are then discharged from the furnace.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: July 21, 1998
    Assignee: Maumee Research & Engineering, Inc.
    Inventors: Franklin G. Rinker, Deane A. Horne
  • Patent number: 5601631
    Abstract: A process for recovering iron from iron-bearing materials including steel mill waste and iron-bearing ores. The process includes the steps of combining the iron-bearing materials, having metal oxides including iron oxides therein, with carbonaceous material to form a dry mixture. The dry mixture is agglomerated under conditions sufficient to mobilize volatile matter from the carbonaceous material to function as a binder and bond the dry mixture and form green compacts. The green compacts are then loaded into a preheated rotary hearth furnace void of compacts to form a layer of compacts no more than about two compacts high. The green compacts are heated for about 5 to 12 minutes at a temperature of between about 2150.degree. F. to 2350.degree. F. to reduce the compacts and evolve undesirable oxides from the compacts. The reduced compacts are then discharged from the rotary hearth furnace whereupon they are soaked to provide additional time for reaction to achieve 99% or more reduction of the iron oxides.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: February 11, 1997
    Assignee: Maumee Research & Engineering Inc.
    Inventors: Franklin G. Rinker, Deane A. Horne
  • 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: 5256186
    Abstract: A method for the treatment of a mixture of lead dusts and pyritic concentrates said method including the steps of:a) feeding a mixture of lead dust and pyritic concentrate to a furnace containing molten slag;b) smelting the mixture by injecting air or oxygen enriched air into the slag by means of a submerged lance to produce a lead bearing slag; andc) recycling fume to the furnace.A method for the treatment of lead dusts, without pyritic concentrate, said method including the steps of:a) feeding lead dust to a furnace containing molten slag;b) smelting the dust by injecting air or oxygen enriched air into the slag by means of a submerged lance to produce a lead bearing slag; andc) recycling fume to the furnace.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: October 26, 1993
    Assignee: Mount Isa Mines Limited
    Inventors: Roger L. Player, Steven P. Matthew
  • Patent number: 5246484
    Abstract: In the reduction of liquid slags or molten salts which contain nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal, carbonaceous reducing agents and oxygen-containing gas are injected through nozzles into the metal layer. In order to improve the gasification of the reducing agent the height of the metal layer is so selected that at least 50% of the reducing agent are reacted to CO and optionally H.sub.2 in the metal layer before the reducing agent enters the slag layer.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: September 21, 1993
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventor: Lutz Deininger
  • Patent number: 5186741
    Abstract: The invented pellet reclamation process includes forming green pellets of a mixture of steel furnace dust, a carbonaceous material such as coal, charcoal, lignite, petroleum coke, or coke, and an organic binder. The green pellets are fed over a layer of burnt pellets on a rotary hearth furnace which successively conveys the pellets first through a drying and coking zone in which the pellets are dried and any volatile matter driven out of the carbonaceous material. The pellets then travel through a reduction zone where the pellets are subjected to a higher temperature at which the contained iron oxide is reduced and remains within the pellets and the zinc, lead and cadmium oxides are reduced, volatilized, re-oxidized and carried off as oxides in the waste gases. The reduced pellets (DRI) are ultimately carried into a discharge zone where they are discharged from the rotary hearth furnace. An apparatus for performing the process is also disclosed.
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: February 16, 1993
    Assignee: Zia Patent Company
    Inventors: Norman L. Kotraba, Carl A. Holley
  • Patent number: 5139567
    Abstract: There is disclosed a process for recovering valuable metals from a dust containing zinc comprising mixing the dust containing zinc with a reductant and a flux for regulating the basicity of slag, forming the mixture into pellets with a pelletizer, charging the pellets into a shaft type preheating-prereducing furnace provided with a preheating zone at the upper part and with a reducing zone at the lower part and removing, in the preheating zone, moisture and ignition loss components in the pellets, while prereducing in the reducing zone, the pellets under such conditions that a reduction of iron oxide is made to proceed selectively while the reduction of zinc oxide is suppressed to the possible minimum, charging the prereduced pellets into a melting furnace to melt and reduce them in the furnace, separating zinc, or zinc and lead, by evaporation followed by condensation to recover them, and separating iron and lead, or iron, according to the difference in their specific gravities to recover the iron as a molte
    Type: Grant
    Filed: April 10, 1991
    Date of Patent: August 18, 1992
    Assignee: Sumitomo Heavy Industries, Ltd.
    Inventors: Toshio Matsuoka, Yukio Koyabu, Shinichi Kurozu
  • Patent number: 5108497
    Abstract: Indium-containing feedstocks, such as flue dusts from a refining or smelting process, are treated to increase the concentration of indium and at the same time to reduce the concentrations of lead, copper, and arsenic. The flue dusts are treated in a sodium-doped lead bath at temperatures of 675.degree. to 800.degree. C. Soda ash in the amount of 15 to 35 weight percent is blended with the feed stock and added to the sodium-doped lead bullion. The sodium reacts with the dusts to form a liquid dross, which is removed, cooled, and crushed. The powdered dross is water leached to remove the sodium salts. The indium remains in the filler cake and can be processed by conventional methods for the recovery of indium. About 95% of the indium reports to the filter cake, while lead retention in the filter cake is only about 5-15% of the initial lead content in the dust. A majority of the zinc also reports to the filter cake.
    Type: Grant
    Filed: September 5, 1990
    Date of Patent: April 28, 1992
    Assignee: Indium Corporation of America
    Inventors: Nicholas B. Gomez, John P. Hager, Charles E. T. White, Laurence G. Stevens
  • Patent number: 4963182
    Abstract: A method and apparatus for recovering primary metals from pyrometallurgical process dust, in which a vertical shaft retort, situated in a furnace or afterburner associated with a pyrometallurgical apparatus, such as an inclined rotary reduction smelter, and preferably having a tapered cross-section with the larger end at the bottom, receives greenball pellets from a pelletizer, vaporizes volatile metal metals therein, and removes them to an associated volatile metal recovery apparatus, while reducing and recovering the major metal oxide components in the pellets in metallized form.
    Type: Grant
    Filed: March 14, 1989
    Date of Patent: October 16, 1990
    Assignee: Zia Technology, Inc.
    Inventors: Norman G. Bishop, N. Edward Bottinelli, Norman L. Kotraba