Nonferrous Patents (Class 75/585)
  • Publication number: 20090064820
    Abstract: In the operation, a flux mainly composed of silica ore and a non-ferrous metal-ore raw-material are charged into a smelting furnace via a conveying system. In order to increase the production amount of the metal, the flux is conveyed and treated through a first system, in which the flux is crushed in a ball mill and dried in the ball mill while hot air is blown into the ball mill, and the crushed and dried flux is conveyed directly before the smelting furnace. In the drier of copper concentrate, the flux is not dried at all.
    Type: Application
    Filed: June 30, 2008
    Publication date: March 12, 2009
    Applicant: Pan Pacific Copper Co., Ltd.
    Inventors: Kenta Nakagawa, Yutaka Yasuda, Yoshiaki Suzuki
  • Publication number: 20090007729
    Abstract: The proposed invention relates to methods of precious metal recovery and may be applied to the recovery of precious metals from various types of mineral raw source materials containing chlorides of alkali and earth metals, e.g. collective concentrate produced from clay-salt residue of potassium production, or marker clays, etc. This method includes chlorinating roasting of the collective concentrate produced during enrichment of the material with residual chlorides content of 7-13%, or natural concentrate with up to 15% chlorides content. Thereafter, the cinder is leached by an aqua-regia solution, the precious metals are recovered from the pulp via of sorption, chlorinating roasting is held at 600-700° C., the precious metals are leached from the cinder using diluted solution of aqua-regia, and then via sorption. The process is cost-efficient due to the use of chlorinating agent, reduction of the process steps number, decreasing of the roasting temperature, and the leaching by diluted acid.
    Type: Application
    Filed: January 9, 2007
    Publication date: January 8, 2009
    Inventors: Viktor Andreevich Sinegribov, AndreiFilippovich Smetannikov, TatyanaBorisovna Udina, PavelUrievich Novikov, Izabella Alekseevna Logvinenko, ArkadiyEvgenievich Krasnoshtein
  • Patent number: 6887298
    Abstract: The present invention relates to a method and equipment, whereby matte with a high non-ferrous metal content and disposable slag are produced simultaneously in a suspension-smelting furnace from non-ferrous sulphide concentrate. According to the invention, a carbonaceous reducing agent is charged to the lower furnace of a suspension smelting furnace via tuyeres to the part of the furnace which has a reduced cross-sectional area.
    Type: Grant
    Filed: May 4, 2000
    Date of Patent: May 3, 2005
    Assignee: Outokumpu Oyj
    Inventors: Ilkka Kojo, Markku Kytö
  • Patent number: 6814779
    Abstract: A process for metal purification comprising a first step for heating a feed metal in a feed crucible to generate a vapor of the metal, a second step for directing the vapor into a condensation passageway for vapors, where part of the vapor is condensed to generate a molten condensate, a third step for directing the vapor through the condensation passageway for vapors into a solidification crucible so that the vapor is cooled to solidify said metal in a high-purity form, and a fourth step for returning the molten condensate into the feed crucible.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: November 9, 2004
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Kishio Tayama, Shunichi Kimura
  • Patent number: 6755890
    Abstract: The present invention relates to a method, whereby the non-ferrous metal content of the slag generated in the production of non-ferrous metals such as copper or nickel in a suspension smelting furnace is reduced by charging metallurgical coke, with a size ranging from 1-25 mm, into the furnace. Baffles can be positioned from the roof of the furnace downwards, by means of which small particles containing copper and nickel are prevented from drifting to the back of the furnace and being tapped with the slag. The baffles force the small particles to settle in the reduction zone of the furnace.
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: June 29, 2004
    Assignee: Outokumpu Oyj
    Inventors: Pekka Hanniala, Ilkka Kojo, Risto Saarinen
  • Patent number: 6685764
    Abstract: This invention relates to a method for preventing the ignition of molten magnesium by contacting the molten magnesium with a gaseous mixture comprising a fluorocarbon selected from the group consisting of perfluoroketones, hydrofluoroketones, and mixtures thereof.
    Type: Grant
    Filed: March 22, 2003
    Date of Patent: February 3, 2004
    Assignee: 3M Innovative Properties Company
    Inventors: Dean S. Milbrath, John G. Owens
  • Patent number: 6682585
    Abstract: An improved method of processing both primary and secondary nonferrous metal and alloys of said metals using a refining gas is provided. The improvement involves refining said non-ferrous metal and alloys with a gaseous mixture including at least one compound selected from the group consisting of ClF3, ClF, COF2, F3COF, CF2(OF)2, SO2F2, NF3, SO2ClF, SOF2, SOF4, NOF, F2 and SF4.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: January 27, 2004
    Assignee: Air Products and Chemicals, Inc.
    Inventors: John Peter Hobbs, James Francis Heffron, Zbigniew Zurecki
  • Patent number: 6576040
    Abstract: All of the air is compressed in a single compressor, which feeds a smelter for smelting ore, a converter for converting matte coming from the smelter and an air separation unit which delivers two oxygen streams for enriching the air. A buffer tank is used to deliver a variable flow of enriched air to the converter.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: June 10, 2003
    Assignee: L'Air Liquide - Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Didier Magnet, Norbert Rieth
  • Patent number: 6572675
    Abstract: A furnace system for recovering a non-ferrous metal from a charge of material containing the metal. The furnace system having a furnace chamber having walls defining a refractory chamber, the refractory chamber receiving the charge of material and the metal contained in the charge of material being heated into a flowable mode in the refractory chamber. The furnace system having at least one paddle radially projecting from an interior surface of the furnace chamber toward a longitudinal axis of the furnace chamber. Other features of the invention include a door having a closed position adjacent an inlet passage to the furnace chamber, the door having rollers and a suspension. Other features of the invention include a motor and a control unit which monitors torque to rotate the furnace chamber as an indication of viscosity of the charge of material. Methods of operating a furnace system for recovering non-ferrous metal from a charge of material containing the metal are also discussed.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: June 3, 2003
    Assignee: MDY L.L.C.
    Inventor: Moshe Yerushalmi
  • Patent number: 6537346
    Abstract: This invention relates to a method for preventing the ignition of molten magnesium by contacting the molten magnesium with a gaseous mixture comprising a fluorocarbon selected from the group consisting of perfluoroketones, hydrofluoroketones, and mixtures thereof.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: March 25, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Dean S. Milbrath, John G. Owens
  • Patent number: 6521018
    Abstract: An improved method of processing a nonferrous metal and alloys of said metal using a blanketing gas having a global warming potential is provided. The improvement involves reducing the global warming potential of the blanketing gas by blanketing the nonferrous metal and alloys with a gaseous mixture including at least one compound selected from the group consisting of COF2, CF3COF, (CF3)2CO, F3COF, F2C(OF)2, SO2F2, NF3, SO2ClF, SOF2, SOF4, NOF, F2 and SF4.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: February 18, 2003
    Assignee: Air Products and Chemicals, Inc.
    Inventors: John Peter Hobbs, James Francis Heffron, Andrew Joseph Woytek, Zbigniew Zurecki
  • Publication number: 20020166413
    Abstract: An improved method of processing both primary and secondary nonferrous metal and alloys of said metals using a refining gas having a global warming potential is provided. The improvement involves reducing said global warming potential of said refining gas by refining said non-ferrous metal and alloys with a gaseous mixture including at least one compound selected from the group consisting of ClF3, ClF, COF2, F3COF, CF2(OF)2, SO2F2, NF3, SO2ClF, SOF2, SOF4, NOF, F2 and SF4.
    Type: Application
    Filed: January 16, 2002
    Publication date: November 14, 2002
    Inventors: John Peter Hobbs, James Francis Heffron, Zbigniew Zurecki
  • Patent number: 6398844
    Abstract: An improved method of processing a molten non-ferrous metal and alloys of the metal using a blanketing gas having a global warming potential is provided. The improvement involves reducing the global warming potential of the blanketing gas by blanketing the molten non-ferrous metal and alloys with a gaseous mixture including at least one compound selected from the group consisting of SO2F2, NF3, SO2CLF, SOF4, and NOF.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: June 4, 2002
    Assignee: Air Products and Chemicals, Inc.
    Inventors: John Peter Hobbs, James Francis Heffron, Andrew Joseph Woytek
  • Patent number: 6387154
    Abstract: A process for separating molten metals, the molten metals being treated with metal hydrides is provided. The molten metals employed are from Groups II-IV of the Periodic Table of Elements and the subgroups, including their alloys, and are distinguished by the fact that the metals or alloys are reacted with a metal hydride in a molten bath.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: May 14, 2002
    Assignee: Th. Goldschmidt AG
    Inventors: Georg Frommeyer, Wilfried Knott, Andreas Weier
  • Publication number: 20010027702
    Abstract: An improved method of processing a nonferrous metal and alloys of said metal using a blanketing gas having a global warming potential is provided. The improvement involves reducing the global warming potential of the blanketing gas by blanketing the nonferrous metal and alloys with a gaseous mixture including at least one compound selected from the group consisting of COF2, CF3COF, (CF3)2CO, F3COF, F2C(OF)2, SO2F2, NF3, SO2ClF, SOF2, SOF4, NOF, F2 and SF4.
    Type: Application
    Filed: February 9, 2001
    Publication date: October 11, 2001
    Inventors: John Peter Hobbs, James Francis Heffron, Andrew Joseph Woytek, Zbigniew Zurecki
  • 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: 6096110
    Abstract: The invention relates to a method for cleaning slag, created in metallurgical processes of non-ferrous metals, in an electric furnace, and particularly the method is related to a semi-continuous cleaning process. According to the novel method, the electric furnace is provided with at least two slag tapping holes, the lower of which is arranged on the same level as the tap hole in a conventional, batchwise operated furnace, and the second tap hole is located higher up, either at the height of the feed inlet or only slightly underneath it.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: August 1, 2000
    Assignee: Outokumpu OYJ
    Inventor: Tarmo Mantymaki
  • Patent number: 6093235
    Abstract: A process for decarburizing a steel melt for the production of high-chromium steels by blowing in oxygen in which the decarburization rate is continuously measured and the amount of oxygen to be injected is adjusted depending on the measured values. The following controlled quantities are calculated:a) the duration of the Al--Si oxidation phase at the start of the decarburization process,b) the duration of a principle decarburization phase immediately following the Al--Si oxidation phase until the transition point from the decarburization reaction to the metal oxidation is reached, andc) the decarburization rate in the principal decarburization phase. The injected oxygen quantity is increased at an accelerated rate immediately following the Al--Si oxidation phase to the oxygen quantity of the principal decarburization phase until the decarburization rate calculated in c) is reached.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: July 25, 2000
    Assignee: Mannesmann AG
    Inventor: Johann Reichel
  • Patent number: 6010553
    Abstract: In a process for producing pig iron, nonferrous heavy metal alloys, ferrochromium carbure or carbon-free ferrochromium and synthetic blast furnace slags, using metal-oxide-containing waste incineration residues or slags, the charging materials of waste burning, e.g., car shredder light fractions and/or metallurgical dusts, are at least partially oxidized and subsequently are reduced while separating nonferrous metals or alloys, whereupon the oxidic slag phase depleted from metals or alloys is mixed with liquid steelworks slag optionally upon further addition of metallurgical dusts, whereupon crude steel is drawn off while lowering the viscosity of the steelworks slag and the remaining slag portion is subjected to further reduction while recovering pig iron and optionally Fe chromium alloys, whereupon the resulting synthetic blast furnace slag is discharged.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: January 4, 2000
    Assignee: "Holderbank" Financiere Glarus AG
    Inventors: Alfred Edlinger, Albert Waschnig
  • Patent number: 5882377
    Abstract: In this invention, the smelting reduction operation can be carried out in a high efficiency by charging a carbonaceous material in such an amount that total surface area is not less than 60 m.sup.2 per 1 ton of slag weight. Carbon substance finely particulating through thermal crumbling under a high-temperature atmosphere inside the vessel is used as the carbonaceous material, whereby it is possible to stably conduct the smelting reduction while controlling the scattering of the carbonaceous material, and also the erosion, particularly locally erosion of refractory in the smelting reduction furnace, which was a serious problem in the conventional technique, can considerably be decreased to largely prolong the service life of refractory.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: March 16, 1999
    Assignee: Kawasaki Steel Corporation
    Inventors: Kimiharu Aida, Shuji Takeuchi, Nagayasu Bessho, Tomomichi Terabatake, Yasuo Kishimoto, Hiroshi Nishikawa, Fumio Sudo
  • 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: 5849061
    Abstract: A process for refining high-impurity blister copper to anode quality copper is disclosed. In an oxidation step of a blister copper refining stage, soda ash fluxing removes antimony and arsenic while also removing sulfur and iron. In a deoxidation step of the blister copper refining stage, sulfur hexafluoride is injected at a controlled oxygen concentration to remove bismuth while reducing the oxygen content. Slag is continuously or periodically skimmed from the surface of the molten blister copper to prevent re-entry of impurities. The process may be carried out in batch operation or, in a preferred embodiment, in continuous flow-through operation.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: December 15, 1998
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: Nickolas J. Themelis, Baozhong Zhao
  • 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: 5669957
    Abstract: A dross compression apparatus and method utilizes a dross compression head and a skim box or collector having mating ribs. The ribs may be any type of projection or shape of the head and skim box sufficient to form grooves in both sides of the dross which divide or substantially divide the dross. Improved plating of the aluminum metal and separation of the aluminum layers from the aluminum oxide are achieved by using pressures in the range of 50 to 70 pounds per square inch. The ribs by their cutting action through the dross enable the achieving of these pressures with lower rated hydraulic presses. Two specific embodiments are disclosed, one utilizing an elongated substantially hemispheric shaped head and the other utilizing a substantially hemispheric shaped head. In both embodiments, the head and receptacle or skim box are of substantially conforming shapes.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: September 23, 1997
    Assignee: Altek International, Inc.
    Inventor: David J. Roth
  • Patent number: 5658368
    Abstract: A pyrometallurgical vessel suitable for continuous or semicontinuous smelting and/or conversion of molten base metal sulfide feed materials. The top blown, bottom stirred vessel includes oxidizing gas lances and feed pipes directing their respective contents directly or indirectly into bath eyes opened up in the molten bath by gas injected through porous plugs disposed at the base of the vessel. Low space velocities in the vessel result in reduced dusting.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: August 19, 1997
    Assignee: INCO Limited
    Inventors: Carlos Manuel Diaz, Samuel Walton Marcuson, Anthony Edward Warner, Geoffrey Edwin Osborne
  • Patent number: 5591248
    Abstract: The invention relates to a method and a device for melting or processing metal. The metal material is batched into a chamber (1) and circulated from one chamber to another (3, 5, 10, 11, 15, 18) with simultaneous melting under the effect of thermal radiation from the chamber lids. One or more pumps act on the pressure above the molten metal in one or more pump chambers (10, 11), connected with a melt chamber (5) and with a splash chamber (18, 15), from where the melt is discharged or recycled. The object of the invention is to upgrade melt quality by reducing turbulence in the melt chambers. This object has been achieved by transferring, at an increased pressure in the pump chamber, a substantially greater amount, approx. three to fifteen times more melt per time unit from each pump chamber (10, 11) to the splash chamber (18, 15) than from the same pump chamber to the splash chamber (5).
    Type: Grant
    Filed: April 20, 1994
    Date of Patent: January 7, 1997
    Assignee: AB Jafs Export Oy Holimesy
    Inventors: Lars H. M. J.ang.fs, Daniel J.ang.fs
  • Patent number: 5540752
    Abstract: A process and apparatus are disclosed for recovering a non-ferrous metal, preferably aluminum and aluminum alloys, in molten coherent form from a charge of material to be processed containing the metal. The charge is introduced into a sealable furnace which is then sealed. The charge is agitated. A control parameter indicative of conditions inside said furnace is monitored and compared to a pre-determined first condition for the parameter. A heat source is operated to heat the charge until the control parameter reaches the first condition. The operation of the heat source is then stopped. A controlled amount of oxidizing agent and an inert carrier is then introduced into the furnace. The control parameter is monitored and compared to a predetermined second condition for the parameter. The flow of the oxidizing agent and the carrier is controlled to maintain the control parameter at about the second condition. The molten metal is subsequently removed from the furnace.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: July 30, 1996
    Inventor: Han Spoel
  • Patent number: 5527380
    Abstract: A method for recovering non-ferrous metal from a dross that includes the non-ferrous metal includes introducing the dross into a rotary furnace or rotatable converter. The furnace or converter has a refractory lining. Oxygen and a fossil fuel are supplied to an oxy-fuel burner. The oxygen is supplied as a combustion gas including at least eighty percent oxygen. The oxygen and fossil fuel are combusted to generate an initial combustion energy. The dross is heated to a temperature above a melting point of the non-ferrous metal by supplying the initial combustion energy to the furnace or converter. The heating takes place in the absence of a protective salt layer. The non-ferrous metal and a non-metallic residue are recovered from the furnace or converter.
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: June 18, 1996
    Assignees: AGA Aktiebolag, Hoogovens Aluminium Huttenwerk GmbH
    Inventors: Henrik Gripenberg, Hans-Walter Grab, Michael Mullerthann
  • Patent number: 5518524
    Abstract: A vertical shaft furnace for melting non-ferrous metals, such as copper, aluminum, and their alloys, includes metal blocks disposed in an annular wall just beneath the charging section of the furnace. Preheated air is forced into the furnace shaft through openings in the wall of metal blocks to burn or oxidize substantially all the CO gas contained in the combustion gases rising from the melting chamber of the furnace. A pressurized plenum surrounding the shaft adjacent the charge opening is used to preheat ambient air which is then supplied under pressure to another plenum above the melting chamber where the preheated air is introduced into the shaft.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: May 21, 1996
    Assignee: Southwire Company
    Inventors: Thomas N. Wilson, Milton E. Berry, John D. Butler, Thomas H. Crumbley, Peter W. Ware
  • Patent number: 5423900
    Abstract: The invention relates to a method for blowing oxidizing gases into molten metal located in a reaction vessel having tuyeres below the metal bath surface, whereby the oxidizing gases are blown into the molten metal from these tuyeres and fed to the tuyeres at an inlet pressure between 85 bars and 170 bars.
    Type: Grant
    Filed: October 19, 1993
    Date of Patent: June 13, 1995
    Assignee: KCT Technologie GmbH
    Inventors: Klaus Klintworth, Rainer Zechner, Rudolf Flesch, Manfred Redetzky, Harald Berger, Johannes Steins
  • Patent number: 5300136
    Abstract: Scrap aluminum is reclaimed by a salt flux-based reclamation process using potassium chloride in place of the commonly used sodium chloride. The spent flux which remains after the recovery of the aluminum is useful as a soil fertilizer, with the potassium content of the flux serving as a source of potassium nutrient for the soil. The potassium in the spent flux is highly water soluble at all values of pH while the aluminum in the spent flux remains at a limited solubility, particularly under the conditions expected to be encountered in soil. Thus, despite the known phytotoxicity of aluminum and the presence of aluminum in the spent flux, the spent flux is discovered to be useful as a plant fertilizer with the maximum benefit from the potassium and minimal if any harm from the aluminum.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: April 5, 1994
    Assignee: Imco Recycling, Inc.
    Inventors: William O. Stauffer, F. Robert Hubbard
  • Patent number: 5281252
    Abstract: The invention relates to the smelting or converting of particulate sulfide material, such as nickel or copper sulfide. A molten seed bath of smelted or converted material is provided in a reaction vessel. Particulate sulfide material is injected into a reaction vessel below the surface of the melt. Top blowing with an oxygen-containing gas generates heat and brings about the oxidation of the sulfides with a significant decrease in the amount of dust generated. Optional bottom stirring with a non-reactive gas such as nitrogen may further increase efficiency.
    Type: Grant
    Filed: December 18, 1992
    Date of Patent: January 25, 1994
    Assignee: Inco Limited
    Inventors: Carlos A. Landolt, Samuel W. Marcuson, David E. Hall
  • 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: 5104445
    Abstract: The present invention is a process to recover metals from refractory ores. It involves the chlorination of an ore concentrate in the presence of solid salt at a temperature between 300.degree. and 650.degree. C. Thereafter, an oxidation step can be used to convert iron chloride to iron oxide. Subsequent separation steps remove the salt, gangue, and iron oxides. Separate pathways are described for precious and base metal recovery.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: April 14, 1992
    Assignee: Chevron Research & Technology Co.
    Inventors: Michael Dubrovsky, Paul J. Marcantonio
  • Patent number: 5076838
    Abstract: An apparatus for directly reducing pellets of material without melting the material includes the transporting of the pellets through drying and preheating zones on an oxidizing traveling grate and reduction in a ported rotary kiln. There is a kiln having a first end and a second end with the first end being substantially adjacent to the heating and oxidizing component for receipt of the pellets therefrom. The kiln is inclined downwardly and is rotated to advance the pellets through the kiln from the first end to the second end thereof. The kiln includes an induration zone for indurating the pellets. The induration zone is adjacent to the first end and remote from the second end and extends for a substantial portion of the kiln from the first end. The kiln includes a reduction zone extending from the downstream end of the induration zone to the second end. A device is used to inject a reducing agent into the reduction zone of its kiln for making contact with the pellets advancing through the reduction zone.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: December 31, 1991
    Assignee: Svedala Industries, Inc.
    Inventor: David W. Rierson