Patents Assigned to Elkem ASA
  • Patent number: 7918916
    Abstract: The present invention relates to a calcium-silicate based slag having a phosphorus content of less than 3 ppmw. The invention further relates to a method for producing low phosphorus calcium-silicate based slag, where molten calcium-silicate based slag is treated with a molten ferrosilicon alloy in a vessel, whereby phosphorus in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and a low phosphorus calcium-silicate based slag is removed from the vessel.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: April 5, 2011
    Assignee: Elkem ASA
    Inventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstad
  • Patent number: 7879130
    Abstract: The present invention relates to a calcium-silicate based slag having a phosphorous content of less than 3 ppmw. The invention further relates to a method for producing a low phosphorous calcium-silicate based slag, where molten calcium-silicate based slag is treated with a molten ferrosilicon alloy in a vessel, whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and a low phosphorous calcium-silicate to based slag is removed from the vessel.
    Type: Grant
    Filed: March 3, 2008
    Date of Patent: February 1, 2011
    Assignee: Elkem ASA
    Inventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstrad
  • Patent number: 7854784
    Abstract: A method for making solar grade silicon from metallurgical grade silicon is accomplished by treating a calcium silicate based slag with ferrosilicon in the first vessel so as to obtain a purification of the calcium silicate based slag. In a second vessel, the purified calcium based silicate slag is used to treat metallurgical grade silicon in order to obtain a solar grade silicon. The purification of calcium silicate based slag in the first vessel is accomplished to reduce phosphorous to a level of less than 3 ppmw.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: December 21, 2010
    Assignee: Elkem ASA
    Inventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstad
  • Publication number: 20090274608
    Abstract: A method for making solar grade silicon from metallurgical grade silicon is disclosed, which including, treating a calcium-silicate based slag by molten calcium-silicate based slag in a first vessel, whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy producing a calcium-silicate based containing less than 3 ppmw phosphorous; obtaining the calcium-silicate based slag containing less than 3 ppmw phosphorous from the first vessel; treating a molten metallurgical grade silicon in a second vessel with the calcium-silicate based slag containing less than 3 ppmw phosphorous to reduce the content of phosphorous, boron and iron in the metallurgical grade silicon; and removing solar grade silicon with low content of phosphorous, boron and iron from the second vessel.
    Type: Application
    Filed: July 13, 2009
    Publication date: November 5, 2009
    Applicant: ELKEM ASA
    Inventors: Erik ENEBAKK, Gabriella Maria TRANELL, Ragnar TRONSTAD
  • Publication number: 20080206123
    Abstract: The present invention relates to silicon feedstock for producing directionally solidified silicon ingots, thin sheets and ribbons for the production of silicon wafers for PV solar cells where the silicon feedstock contains between 0.2 and 10 ppma boron and between 0.1 and 10 ppma phosphorus distributed in the material. The invention further relates to directionally solidified silicon ingot or thin silicon sheet or ribbon for making wafers for solar cells containing between 0.2 ppma and 10 ppma boron and between 0.1 ppma and 10 ppma phosphorus distributed in the ingot, said silicon ingot having a type change from p-type to n-type or from n-type to p-type at a position between 40 and 99% of the ingot height or sheet of ribbon thickness and having a resistivity profile described by an exponential curve having a starting value between 0.4 and 10 ohm cm and where the resistivity value increases towards the type change point.
    Type: Application
    Filed: April 23, 2008
    Publication date: August 28, 2008
    Applicant: ELKEM ASA
    Inventors: Erik Enebakk, Kenneth Friestad, Ragnar Tronstad, Cyrus Zahedi, Christian Dethloff
  • Publication number: 20080156145
    Abstract: The present invention relates to a calcium-silicate based slag having a phosphorous content of less than 3 ppmw. The invention further relates to a method for producing a low phosphorous calcium-silicate based slag, where molten calcium-silicate based slag is treated with a molten ferrosilicon alloy in a vessel, whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy, and a low phosphorous calcium-silicate to based slag is removed from the vessel.
    Type: Application
    Filed: March 3, 2008
    Publication date: July 3, 2008
    Applicant: ELKEM ASA
    Inventors: Erik ENEBAKK, Gabriella Maria TRANELL, Ragnar TRONSTAD
  • Patent number: 7393407
    Abstract: The present invention relates to a slurry containing water, amorphous silica panicles having a particle size less than 1 micron and silica flour with a particle size between 2-200 microns. In order to stablize the slurry, the slurry contains a polysaccharide. The invention further relates to a method for the production of a slurry containing water, amorphous silica having a particle size below 1 micron, and silica flour with a particle size between 2-200 microns, where a polysaccharide is added to a slurry of water and amorphous silica, whereafter the silica flour is mixed into the slurry of amorphous silica.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: July 1, 2008
    Assignee: Elkem ASA
    Inventors: Eldar O Dingsoyr, Magne Dastol, Cor Oldenziel, Bjorn Vassoy
  • Publication number: 20070128099
    Abstract: The present invention relates to silicon feedstock for producing directionally solidified silicon ingots, thin sheets and ribbons for the production of silicon wafers for PV solar cells where the silicon feedstock contains between 0.2 and 10 ppma boron and between 0.1 and 10 ppma phosphorus distributed in the material. The invention further relates to directionally solidified silicon ingot or thin silicon sheet or ribbon for making wafers for solar cells containing between 0.2 ppma and 10 ppma boron and between 0.1 ppma and 10 ppma phosphorus distributed in the ingot, said silicon ingot having a type change from p-type to n-type or from n-type to p-type at a position between 40 and 99% of the ingot height or sheet or ribbon thickness and having a resistivity profile described by an exponential curve having a starting value between 0.4 and 10 ohm cm and where the resistivity value increases towards the type change point.
    Type: Application
    Filed: January 12, 2004
    Publication date: June 7, 2007
    Applicant: ELKEM ASA
    Inventors: Erik Enebakk, Kenneth Friestad, Ragnar Tronstad, Cyrus Zahedi, Christian Dethloff
  • Patent number: 7226493
    Abstract: The present invention relates to a method for grain refining of steel. A grain refining alloy having a composition FeXY where X is one or more elements selected from the group consisting of Cr, Mn, Si, Ni, and Mo and where Y is one or more oxide and/or sulphide and or nitride and/or carbide forming elements selected from the group consisting of Ce, La, Nd, Pr, Ti, Al, Zr, Ca, Ba, Sr, Mg, C and N where X is between 0.001 and 99% by weight based on the weight of the alloy and where Y is between 0.001 and 50% by weight of the alloy, said alloy additionally containing between 0.001 and 2% by weight of oxygen and/or between 0.001 and 2% by weight of sulphur, said alloy containing at least 103 inclusion particles per mm3 consisting of oxides and/or sulphides and/or carbides and/or nitrides of one or more of the Y elements and/or one or more of the X elements Cr, Mn and Si in addition to Fe, said inclusion particles having a mean diameter of less than 10 ?m, is added to molten steel in an amount of between 0.
    Type: Grant
    Filed: January 29, 2001
    Date of Patent: June 5, 2007
    Assignee: Elkem ASA
    Inventors: Oystein Grong, Ole Svein Klevan
  • Patent number: 7169207
    Abstract: The device and method of the present invention employs a column having a gas inlet in its lower part and a gas outlet in its upper part. Carbon particles are introduced into the column through a supply pipe. The supply pipe is movable so that by manipulating the height of the supply pipe in conjunction with discharging particulate matter through the column, the height of the bed of particulate matter in the column can be adjusted so that the retention time of the off gas in the particulate bed is constant. By maintaining a constant retention time of the off gas in the bed, complete conversion of the off gas is achieved.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: January 30, 2007
    Assignees: Alcoa Inc., Elkem ASA
    Inventors: Olaf Trygve Vegge, Jon Christian Brinch
  • Publication number: 20060013721
    Abstract: The present invention relates to high strength, oxidation and wear resistant titanium-silicon base alloy containing: 2.5-12 wt % Si 0-5 wt % Al 0-0.5% B 0-2% Cr 0-1 wt % rare earth metals and/or scandium balance Ti with unavoidable impurities.
    Type: Application
    Filed: September 8, 2004
    Publication date: January 19, 2006
    Applicant: ELKEM ASA NORWEIGAN CORPORATION
    Inventors: Georg Frommeyer, Karl Forwald, Gunnar Halvorsen, Kai Johansen, Oyvind Mikkelsen, Gunnar Schussler
  • Publication number: 20050172864
    Abstract: The present invention relates to a slurry containing water, amorphous silica particles having a particle size less than 1 ?m and silica flour with a particle size between 2-200 ?m. In order to stabilize the slurry, the slurry contains a polysaccharide. The invention further relates to a method for the production of a slurry containing water, amorphous silica having a particle size below 1 ?m, and silica flour with a particle size between 2-200 ?m, where a polysaccharide is added to a slurry of water and amorphous silica, whereafter the silica flour is mixed into the slurry of amorphous silica.
    Type: Application
    Filed: April 24, 2003
    Publication date: August 11, 2005
    Applicant: Elkem ASA
    Inventors: Eldar Dingsoyr, Magne Dastol, Cor Oldenziel, Bjorn Vassoy
  • Patent number: 6861040
    Abstract: The invention relates to a method for purification of metallurgical grade silicon where a calcium containing compound is added to molten silicon prior to or after the silicon is tapped from the furnace. The silicon is cast and solidified at a relatively high cooling rate and the solidified silicon is crushed and subjected to a purification process consisting of two leaching steps. In the first leaching step the silicon is treated with an aqueous solution of FeCl3 or FeCl3 and HCl which causes disintegration of the silicon, and in the second leaching step the silicon is treated with an aqueous solution of HF or HF/HNO3. Calcium-containing compound is added to the molten silicon in an amount necessary to provide between 0.3 and 0.95% by weight of calcium in the molten silicon and the weight ratio between Al and Fe in the molten silicon is regulated to between 0.5 and 2.0 by addition of aluminum to the molten silicon.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: March 1, 2005
    Assignee: Elkem ASA
    Inventors: Bruno Ceccaroli, Kenneth Friestad
  • Patent number: 6849101
    Abstract: In a method for recovering Al from an off-gas (3,4) produced during carbothermic reduction of aluminum utilizing at least one smelter (1,2), the off-gas (3,4) is directed to an enclosed reactor (5) which is fed a supply of wood charcoal (7) having a porosity of from about 50 vol. % to 85 vol. % and an average pore diameter of from about 0.05 ?m to about 2.00 ?m, where the wood charcoal (7) contacts the off-gas (3,4) to produce at least Al4C3 (6), which is passed back to the smelter (1,2).
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: February 1, 2005
    Assignees: Alcoa Inc., Elkem ASA, Carnegie Mellon University
    Inventors: Richard J. Fruehan, Yun Li, Gerald Carkin
  • Patent number: 6811677
    Abstract: The present invention relates to an electrolytic cell for the production of aluminum comprising an anode and an electrolytic tank where the electrolytic tank comprises an outer shell made from steel and carbon blocks in the bottom of the tank forming the cathode of the electrolytic cells. At least a part of the sidewall of the electrolytic tank consists of one or more evaporation cooled panels, and wherein high temperature, heat resistant and heat insulating material is arranged between the evaporation cooled panels and the steel shell. The invention also includes a method for maintaining a crust on the sidewall of the tank and for recovering heat from the cooling medium inside the panel for transformation into electrical energy.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: November 2, 2004
    Assignee: Elkem ASA
    Inventors: Jan Arthur Aune, Kai Johansen, Per Olav Nos
  • Patent number: 6809144
    Abstract: The present invention relates to thermoplastic resin compositions, particularly polyolefines, polyvinylchloride and polyamide. The thermoplastic resin compositions contain between 3 and 400% by weight of filler based on the weight of the resin, said filler comprising talc and microsilica where the weight ratio between talc and microsilica is between 15:1 and 1:15. The invention further relates to a method for the production of thermoplastic resin compositions, and to a filler blend for use in thermoplastic resins, said blend containing talc and microsilica in a weight ratio between 15:1 and 1:15.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: October 26, 2004
    Assignees: Elkem ASA, Mondo Minerals Oy
    Inventors: Tore Danielssen, Anne Linnebo, Bjorn Sandelin
  • Patent number: 6805723
    Abstract: A hollow partition wall is employed to feed carbon material to an underflow of a carbothermic reduction furnace used to make aluminum. The partition wall divides a low temperature reaction zone where aluminum oxide is reacted with carbon to form aluminum carbide and a high temperature reaction zone where the aluminum carbide and remaining aluminum oxide are reacted to form aluminum and carbon monoxide.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: October 19, 2004
    Assignees: Alcoa Inc., Elkem ASA
    Inventors: Jan Arthur Aune, Kai Johansen
  • Patent number: 6702994
    Abstract: The present invention relates to a method for production of amorphous silica from particulate materials containing at least 50% elemental silicon, where the silicon-containing material is supplied to a combustion reactor which is heated by an oil- or gas burner and where amorphous silica is recovered after the outlet from the combustion reactor. At least a part of the particulate silicon containing materials are supplied to the combustion reactor in the form of an aqueous slurry. The invention further relates to an apparatus for production of amorphous silica.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: March 9, 2004
    Assignee: Elkem ASA
    Inventors: Knut Henriksen, Olaf Trygve Vegge
  • Patent number: 6696035
    Abstract: The present invention relates to a method for producing microsilica having a reflectivity between 65 and 90% in a smelting furnace for production of ferrosilicon or silicon by using a charge comprising an SiO2 source and a solid carbonaceous reduction agent, where microsilica is recovered from the off-gases from the smelting furnace, wherein the solid reduction agent supplied to the furnace contains an amount of volatile matters of less than 1.25 kg per kg produced microsilica and that the temperature in the gas atmosphere in the furnace above the charge is kept above 500° C.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: February 24, 2004
    Assignee: Elkem ASA
    Inventors: Magne Dastol, Halvard Tveit, Eldar Dingsoyr, Per Ronning, Svein Harsaker
  • Patent number: 6635198
    Abstract: The present invention relates to a method for continuous production of elongated carbon bodies, particularly carbon electrodes which are produced in direct connection with the smelting furnace wherein the electrodes are consumed, where a metallic casing containing unbaked carbonaceous electrode paste comprising a particulate solid carbon material and a carbonaceous binder is continuously or substantially continuously lowered through a baking furnace which is heated to a temperature between 500 and 1200° C.
    Type: Grant
    Filed: January 23, 2001
    Date of Patent: October 21, 2003
    Assignee: Elkem ASA
    Inventors: Arnfinn Vatland, Olaf Trygve Vegge