Patents Assigned to Midrex International B.V. Rotterdam Zurich Branch
  • Patent number: 6749664
    Abstract: An apparatus and method for the direct reduction of iron oxide utilizes a hearth furnace having a vitreous hearth layer of conditioning materials, with the vitreous hearth layer introduced onto a refractory surface of the furnace. The vitreous hearth layer may have upper layers of coating compounds including carbonaceous materials, onto which iron oxide feed material is placed with the carbonaceous materials assisting with segregating the reduced molten iron nuggets from the vitreous hearth layer. The conditioning materials may include compounds such as silicon oxide, magnesium oxide, iron oxides, and aluminum oxide. The conditioning materials are placed in solid or liquid form on the refractory surface, which allows the conditioning materials to raise the melting temperature of the vitreous hearth layer onto which the coating compounds and iron oxide materials are placed.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: June 15, 2004
    Assignee: Midrex International, B.V., Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, David C. Meissner, Kyle J. Shoop
  • Patent number: 6685761
    Abstract: The invention is a method and apparatus for producing beneficiated titanium oxides using a modified rotary hearth furnace, that is a finisher-hearth-melter (FHM) furnace. In the method the refractory surface of the hearth is coated with carbonaceous hearth conditioners and refractory compounds, where onto said hearth is charged with pre-reduced agglomerates. The pre-reduced agglomerates is leveled, then heated until molten, and then reacted with the carbon and reducing gas burner gases until any residual iron oxide is converted to iron having a low sulfur content. Fluid slag and molted iron forms melted agglomerates. The fluid slag is rich in titanium. The melted agglomerates are cooled, and then the melted agglomerates and the hearth conditioners, including the refractory compounds, are discharged onto a screen, which separate the melted agglomerates from the hearth conditioner.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: February 3, 2004
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, Ronald D. Gray
  • Patent number: 6648942
    Abstract: The invention is a method and apparatus for iron-making/steel-making using a modified rotary hearth furnace, that is a finisher-hearth-melter (FHM) furnace. In the method the refractory surface of the hearth is coated with carbonaceous hearth conditioners and refractory compounds, where onto said hearth is charged with pre-reduced metallized iron. The pre-reduced metallized iron is leveled, then heated until molten, and then reacted with the carbon and reducing gas burner gases until any residual iron oxide is converted to iron having a low sulfur content. Nascent slag separates from the molted iron forming carburized iron nuggets. The nuggets are cooled, and then the iron nuggets and the hearth conditioners, including the refractory compounds, are discharged onto a screen, which separate the iron nuggets from the hearth conditioner.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: November 18, 2003
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, Robert M. Klawonn
  • Patent number: 6602317
    Abstract: A method and apparatus for increasing hydrocarbons to a direct reduction shaft furnace while controlling the temperature uniformity of the center portion of the iron burden wherein the hydrocarbon gases used in direct reduction may be preheated, which increases the temperature of the hydrocarbon gases, and therefore increases the resultant temperature of the upflowing gases as it rises from the lower section of the furnace into the center of the burden. Alternatively, a portion of the upflowing gas may be removed before it enters the reduction zone of the furnace. The removed upflowing gas, known as hot bleed gas, may be ducted to the top gas scrubber of the furnace or may be mixed with the main reducing gas stream of the furnace for reintroduction to the furnace. Alternatively, hot reducing gas may be directly injected into the center portion of the burden, offsetting the cooling effect of the upflowing gas.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: August 5, 2003
    Assignee: Midrex International, B.V. Rotterdam, Zurich Branch
    Inventors: Gary E. Metius, Stephen C. Montague, Russell Kakaley, Brian W. Voelker, Russell Eugene Bailey
  • Patent number: 6582491
    Abstract: This invention relates to a method for operation of a moving hearth furnace in conjunction with an electric melter for production of high purity iron product having a range of silicon and manganese, with low sulfur and phosphorus content. The method includes producing high purity iron product and a range of carbon content product from iron oxide and carbon bearing agglomerates, including the steps of providing a furnace for direct reduction of iron oxide and carbon bearing agglomerates, pre-reducing iron and carbon bearing agglomerates in a furnace having a moving hearth surface, producing intermediate carbon-containing metallized iron. An electric melter furnace is utilized for receiving intermediate carbon-containing metallized iron from the pre-reducing step, which is fed directly and continuously into a central interior area of the electric melter, with heating of the carbon-containing metallized iron in the electric melter under elevated temperatures of about 1300° C. to about 1700° C.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: June 24, 2003
    Assignee: Midrex International, B.V. Rotterdam, Zurich Branch
    Inventors: Glenn E. Hoffman, Ronald D. Gray
  • Patent number: 6413295
    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: Grant
    Filed: March 12, 1999
    Date of Patent: July 2, 2002
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Glenn E. Hoffman, Kyle J. Shoop, Takuya Negami, Akira Uragami, Yasuhiro Tanigaki, Shuzo Ito, Isao Kobayashi, Osamu Tsuge, Koji Tokuda, Shoichi Kikuchi
  • Patent number: 6214086
    Abstract: A method and apparatus for simultaneously supplying varying proportions of hot and cold direct reduced iron(DRI) material from a source of hot DRI for melting, storage, briquetting, or transport. The system uses gravity to transport hot DRI material from a reduction furnace to a furnace discharge section, which transports desired amounts to a cooling receptacle and to a hot DRI vessel. The cooling section of the apparatus is connected to the furnace discharge section through a dynamic seal leg. The hot section is also connected to the furnace discharge section through separate a dynamic sealing leg and can feed a surge vessel, a briquetter, a storage vessel or a melting furnace. The method of operation is also disclosed.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: April 10, 2001
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Stephen Craig Montague, Brian William Voelker
  • 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: 6200363
    Abstract: A method and apparatus for discharging cold product or a combination of cold and hot products from a continuous supply of hot direct reduced iron (“DRI”) comprising a product cooler connected to a shaft furnace, with downward movement of the hot DRI and upward concurrent flow of cooling gas through the product cooler. The method and apparatus provides for diverting of hot DRI from an upper portion of the cooler for gravitational transfer to an adjacent storage unit located at a lower elevation than the furnace. The product cooler is situated at a lower height in relation to the furnace, for gravity transfer of a continuous supply of hot DRI through an entry point into the cooler. Cooler provides for cooling gas injection into the lower portion of the cooler, with gas flow upward and counter-current to the hot DRI that descends through the cooler. Recovered cooling gas is scrubbed, cooled, and recycled back for injection into the bottom portion of the cooler.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: March 13, 2001
    Assignee: Midrex International B.V. Rotterdam Zurich Branch
    Inventors: Gilbert Y. Whitten, Jr., James M. McClelland, Jr., Gary E. Metius
  • Patent number: 6146442
    Abstract: An apparatus for the direct reduction of iron oxide utilizing a shaft furnace equipped with a bustle and tuyere system having multiple rows of tuyeres. The bustle and tuyere system utilizes multiple rows of tuyeres to aid in the reduction of gas velocities through the system and to improve burden flow.
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: November 14, 2000
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventor: Daniel J. Sanford
  • Patent number: 5885521
    Abstract: A method and apparatus for producing direct reduced iron from dry compacts composed of iron oxide and carbonaceous material by feeding compacts no more than two layers deep onto a hearth and removing all the volatiles and metallizing the compacts by exposing said compacts to a radiant heat source at a temperature of from about 2400.degree. to about 2600.degree. F. (1316.degree.-1427.degree. C.) for a total time period of about four to ten minutes and partially cooling the compacts while discharging them from the hearth.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: March 23, 1999
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Thomas H. Boyd, James A. Lepinski, Jimmy D. Sloop
  • Patent number: 5730775
    Abstract: A method and apparatus for producing direct reduced iron from dry compacts composed of iron oxide and carbonaceous material by feeding compacts no more than two layers deep onto a hearth and removing all the volatiles and metallizing the compacts by exposing said compacts to a radiant heat source at a temperature of from about 2400.degree. to about 2600.degree. F (1316.degree.-1427.degree. C.) for a total time period of about four to ten minutes and partially cooling the compacts while discharging them from the hearth.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: March 24, 1998
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Thomas H. Boyd, James A. Lepinski, Jimmy D. Sloop
  • Patent number: 5674308
    Abstract: A method and apparatus for producing direct reduced iron from iron oxide fines. The iron oxide raw material are passed through a pre-heater having a spouted port then to a primary spouted bed circulating fluidizing bed reactor and then to a bubbling fluidizing bed reactor. The reaction of the strong reducing gas mixture, through this series of beds allows intimate contact between the fines and small particles with the reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: October 7, 1997
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Kimio Sugiyama, Isao Kobiyashi, Kenji Ohiraki, Shintaro Ano
  • Patent number: 5647887
    Abstract: A method of producing direct reduced iron from pellets, lumps and fines of iron oxide. A mixture of iron oxide raw material is introduced to an apparatus which separates the lumps and pellets from the fines. The lumps and pellets are then introduced to a shaft furnace for direct reduction to iron. Fines are conveyed to a series of fluidizable beds which allows intimate contact with reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: July 15, 1997
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventor: David C. Meissner
  • Patent number: 5618032
    Abstract: Apparatus for the production of iron carbide in a shaft furnace, by reacting a carbon containing reducing gas as the process gas with particulate metal oxide material for an extended residence time at low temperature, including residence time and operating temperature controls. The resulting iron carbide product is also disclosed.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: April 8, 1997
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Winston L. Tennies
  • Patent number: 5529291
    Abstract: A method and apparatus for producing direct reduced iron from iron oxide fines. The iron oxide raw material is conducted through a series of circulating fluidizable beds in which the fluidizing gas is a strong reducing gas mixture, which allows intimate contact between the fines and the reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: June 25, 1996
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventor: David C. Meissner
  • Patent number: 5437708
    Abstract: A method and apparatus for the production of iron carbide in a shaft furnace, by reacting a carbon containing reducing gas as the process gas with particulate metal oxide material for an extended residence time at low temperature.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: August 1, 1995
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: David C. Meissner, Winston L. Tennies
  • Patent number: 5435831
    Abstract: A method of producing direct reduced iron from pellets, lumps and fines of iron oxide. A mixture of iron oxide raw material is introduced to an apparatus which separates the lumps and pellets from the fines. The lumps and pellets are then introduced to a shaft furnace for direct reduction to iron. Fines are conveyed to a series of circulating fluidizable beds which allows intimate contact with reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: July 25, 1995
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventor: David C. Meissner
  • Patent number: 5431711
    Abstract: A method and apparatus for producing direct reduced iron from iron oxide fines. The iron oxide raw material is conducted through a series of circulating fluidizable beds in which the fluidizing gas is a strong reducing gas mixture, which allows intimate contact between the fines and the reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: July 11, 1995
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventor: David C. Meissner
  • Patent number: 4752329
    Abstract: A method of producing a hot, carburized metallized iron product in a generally vertical shaft furnace having an upper reducing zone in which iron oxide reacts with a gaseous reductant, and a lower carbon control and product discharge zone, including: establishing a gravitationally descending iron oxide burden in the furnace; reacting hot gaseous gaseous reductant with the descending burden to form a metallized iron product and a reacted top gas; and injecting a hydrocarbon gas mixture consisting of hot reformed reducing gas and cool natural gas to the product discharge section of the shaft furnace; whereby the carbon content of the metallized iron pellet product is controlled by mixing the reformed gas and natural gas in the proper ratio to balance the endothermic and exothermic reactions within the discharge zone of the furnace.
    Type: Grant
    Filed: March 21, 1986
    Date of Patent: June 21, 1988
    Assignee: Midrex International B.V. Rotterdam, Zurich Branch
    Inventors: Michael N. Freeland, Gregory D. Hughes