Externally Supplied Gas Reductant Patents (Class 75/489)
  • Patent number: 8945273
    Abstract: A process and an apparatus for reducing charge materials containing iron ore or for producing pig iron or liquid primary steel products in a smelting unit are provided, the charge materials being at least partially reduced in at least one reduction unit by means of a reducing gas and optionally at least some of the at least partially reduced charge materials being melted in a smelting unit while supplying coal or coke and gas containing oxygen, while simultaneously forming the reducing gas, and the reducing gas or a reducing gas generated externally being supplied to the reduction unit. In the event of an interruption in the production of pig iron or primary steel products, the at least one reduction unit is emptied and the at least partially reduced charge materials are introduced into at least one vessel and kept under a non-oxidizing shielding gas atmosphere.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: February 3, 2015
    Assignee: Siemens Vai Metals Technologies GmbH
    Inventors: Thomas Eder, Robert Millner, Jan-Friedemann Plaul, Norbert Rein, Karl Zehetbauer
  • Patent number: 8926729
    Abstract: An apparatus for producing a reducing gas for direct reduction iron-making includes an internal-heating type reformer for reforming a natural gas by adding steam and oxygen to the natural gas and by partially burning the natural gas to generate reducing gas containing hydrogen and carbon monoxide; a remover for removing carbon dioxide from exhaust gas generated in the direct reduction iron-making; and a line for recycling as the reducing gas the exhaust gas from which the carbon dioxide is removed by the remover.
    Type: Grant
    Filed: June 23, 2011
    Date of Patent: January 6, 2015
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masaki Iijima, Haruhito Watanabe
  • Patent number: 8753422
    Abstract: A method is disclosed for producing cast iron or semi steel with reducing gas in a high pressure refractory lined shaft furnace using minimal or no coke Iron ore and slag are fed into the operative top zone of the shaft furnace while reducing gas which is generated in a refractory lined gasifier using preheated oxygen is fed through tuyeres at the operative bottom and middle zones. The shaft furnace is operated at a high pressure to increase productivity and to facilitate use of the spent reducing gas downstream. Excess oxygen is fed into the shaft furnace to reduce the carbon content in the molten iron and generate semi steel. The size of the furnace is reduced. The method is economical.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: June 17, 2014
    Inventor: Keki Hormusji Gharda
  • Publication number: 20140150607
    Abstract: A process for direct reduction of iron oxide in a shaft furnace. The furnace has a pre-reduction zone near its uppermost portion, a metallization zone below the pre-reduction zone, an intermediate zone which separates the pre-reduction zone from the metallization zone and which includes a restriction to inhibit rich fuel gas from passing from the pre-reduction zone to the metallization zone, and a cooling zone below the metallization zone at the lowest portion of the furnace.
    Type: Application
    Filed: July 16, 2012
    Publication date: June 5, 2014
    Applicant: HATCH LTD.
    Inventor: Iakov M. Gordon
  • Patent number: 8690987
    Abstract: Carbon iron composite is produced by feeding a formed product of a carbon-containing substance and an iron-containing substance into a carbonization furnace, carbonizing the formed product in a carbonization zone, blowing a coolant gas into the furnace through a coolant-gas-blowing tuyere disposed in a cooling zone to cool carbon iron composite, exhausting a furnace gas through an outlet in a top portion, and discharging the carbon iron composite through a lower portion of the cooling zone.
    Type: Grant
    Filed: July 28, 2010
    Date of Patent: April 8, 2014
    Assignee: JFE Steel Corporation
    Inventors: Takeshi Sato, Tetsuya Yamamoto, Hidekazu Fujimoto, Takashi Anyashiki
  • Patent number: 8685136
    Abstract: A process for reducing iron oxide to metallic iron using coke oven gas (COG), including: a direct reduction shaft furnace for providing off gas; a COG source for injecting COG into a reducing gas stream including at least a portion of the off gas; and the direct reduction shaft furnace reducing iron oxide to metallic iron using the reducing gas stream and injected COG. The COG has a temperature of about 1,200 degrees C. or greater upon injection. The COG has a CH4 content of between about 2% and about 13%. Preferably, the COG is reformed COG. Optionally, the COG is fresh hot COG. The COG source includes a partial oxidation system. Optionally, the COG source includes a hot oxygen burner.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: April 1, 2014
    Assignee: Midrex Technologies, Inc.
    Inventors: Gary E. Metius, James M. McClelland, Jr., David C. Meissner
  • Patent number: 8496730
    Abstract: A process for the direct reduction of iron ore when the external source of reductants is one or both of coke oven gas (COG) and basic oxygen furnace gas (BOFG). Carbon dioxide (CO2) is removed from a mixture of shaft furnace off gas, obtained from a conventional direct reduction shaft furnace, and BOFG. This CO2 lean gas is mixed with clean COG, humidified, and heated in an indirect heater. Oxygen (O2) is injected into the heated reducing gas. This hot reducing gas flows to the direct reduction shaft furnace for use. The spent hot reducing gas exits the direct reduction shaft furnace as shaft furnace off gas, produces steam in a waste heat boiler, is cleaned in a cooler scrubber, and is compressed and recycled to join fresh BOFG. A portion of the shaft furnace off gas is sent to the heater burners. The BOFG and COG are also employed for a variety of other purposes in the process.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: July 30, 2013
    Assignee: Midrex Technologies, Inc.
    Inventors: Gary E. Metius, James M. McClelland, Jr., David C. Meissner
  • Patent number: 8361190
    Abstract: A process and an apparatus for producing sponge iron from iron-oxide-containing material in lump form by direct reduction in a reduction shaft using a reducing gas, wherein the entire reducing gas is introduced by means of a number of reducing gas distribution ducts in a star-like arrangement or arranged parallel to one another, preferably into the lower quarter of the reduction shaft, and evenly distributed over the entire cross-section of the reduction shaft.
    Type: Grant
    Filed: January 19, 2012
    Date of Patent: January 29, 2013
    Assignee: Siemens Vai Metals Technologies GmbH
    Inventor: Bogdan Vuletic
  • Publication number: 20110036203
    Abstract: A method of iron smelting in blast furnace with high temperature coal gas comprises the following steps: (1) charging raw materials consisting of pellets, basic sintered ore, coke and limestone into a blast furnace from top of the furnace, in which the amount of the coke is 125-210 kg per ton of molten iron, raw materials containing iron is composed of 90% pellets and 10% basic sintered ore, and ore grade is above 62%; (2) preheating coal gas to 1250-1450° C. with an horizontal high temperature blast heater, blowing the preheated coal gas having a thermal value of 11.7-12.5 mj/m3 into the blast furnace from top of the furnace at an amount of 1000 m3 per ton of molten iron and a pressure of 0.1-0.6 MPa; blowing air preheated to higher than 1250-1450° C. at an amount of 300-400 n m3 per ton of molten iron. The coal gas used in the method acts as a reducer and fuel, as a result the coke consumption would be reduced.
    Type: Application
    Filed: October 16, 2008
    Publication date: February 17, 2011
    Inventor: Jiule Zhou
  • Publication number: 20020134199
    Abstract: A method for reducing metal oxides in a shaft furnace. A charge of metal oxide and a reductant is reacted in the furnace to produce a primary metal of the metal oxide and an additional secondary metal. The temperature of the off gas from the reaction is controlled to prevent condensing of the secondary metal so that it remains in the off gas for separation therefrom.
    Type: Application
    Filed: March 20, 2001
    Publication date: September 26, 2002
    Inventors: Marcos de Albuquerque Contrucci, Pedro Henrique Carpinetti Costa, Edmar Saul Marcheze
  • Patent number: 6221126
    Abstract: Arrangement for the reduction of metal-oxide-bearing material, particularly of, iron ore, with a reduction vessel in which the metal-oxide-bearing material is reduced in counterflow with reduction gas and which is provided with an inlet for metal-oxide-bearing material, an inlet for reduction gas, an outlet for off-gas and an outlet for reduced material, a vessel for metal-oxide-bearing material, which is connected with the reduction vessel by means of a line and a first supply line for a sealing gas which serves to seal the reduction vessel against the vessel, which first supply line is provided at the connecting line between the vessel and the reduction vessel, characterized in that at least one additional supply line for a sealing gas is provided at the connecting line, which additional supply line is located between the first supply line and the vessel.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: April 24, 2001
    Assignee: Voest-Alpine Industrieanlagenbau GmbH
    Inventor: Gerald Rosenfellner
  • Patent number: 6214084
    Abstract: Iron ore is reduced to molten iron by introducing the ore into a reactor while combusting coal with pure oxygen in the reactor. The molten iron phase, which forms at the bottom of the reactor, is stirred by injecting carbon monoxide into the molten iron. In a preferred embodiment, finely pulverized iron ore is injected with pure oxygen tangentially into a cyclone section of the furnace situated on top of a converter section, thereby causing melting and preliminary reduction of the ore to take place in the cyclone section. Primary reduction of the iron oxide occurs in the converter section of the furnace.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: April 10, 2001
    Assignee: The BOC Group, Inc.
    Inventors: Neeraj Saxena, Paul Alfred Sweeney, Akhilesh Kapoor
  • Patent number: 5407460
    Abstract: A method for modifying existing direct reduction processes and retrofitting existing direct reduction facilities so as to increase the capacity of the facilities without the need for increasing the capacity of external reformers associated with the existing facilities comprises mixing preheated air with the reformed reducing gas produced in the external reformers and containing said mixture with excess natural gas in a reduction-reaction zone of the direct reduction reactor.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: April 18, 1995
    Assignee: C.V.G. Siderurgica Del Orinoco, C.A.
    Inventors: Henry R. Bueno C., Oscar G. Dam G., Pedro Torres, Felipe Gutierrez