Patents Assigned to Elkem ASA
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Patent number: 7918916Abstract: 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: GrantFiled: March 17, 2003Date of Patent: April 5, 2011Assignee: Elkem ASAInventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstad
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Patent number: 7879130Abstract: 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: GrantFiled: March 3, 2008Date of Patent: February 1, 2011Assignee: Elkem ASAInventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstrad
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Patent number: 7854784Abstract: 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: GrantFiled: July 13, 2009Date of Patent: December 21, 2010Assignee: Elkem ASAInventors: Erik Enebakk, Gabriella Maria Tranell, Ragnar Tronstad
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Publication number: 20090274608Abstract: 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: ApplicationFiled: July 13, 2009Publication date: November 5, 2009Applicant: ELKEM ASAInventors: Erik ENEBAKK, Gabriella Maria TRANELL, Ragnar TRONSTAD
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Publication number: 20080206123Abstract: 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: ApplicationFiled: April 23, 2008Publication date: August 28, 2008Applicant: ELKEM ASAInventors: Erik Enebakk, Kenneth Friestad, Ragnar Tronstad, Cyrus Zahedi, Christian Dethloff
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Publication number: 20080156145Abstract: 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: ApplicationFiled: March 3, 2008Publication date: July 3, 2008Applicant: ELKEM ASAInventors: Erik ENEBAKK, Gabriella Maria TRANELL, Ragnar TRONSTAD
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Patent number: 7393407Abstract: 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: GrantFiled: April 24, 2003Date of Patent: July 1, 2008Assignee: Elkem ASAInventors: Eldar O Dingsoyr, Magne Dastol, Cor Oldenziel, Bjorn Vassoy
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Publication number: 20070128099Abstract: 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: ApplicationFiled: January 12, 2004Publication date: June 7, 2007Applicant: ELKEM ASAInventors: Erik Enebakk, Kenneth Friestad, Ragnar Tronstad, Cyrus Zahedi, Christian Dethloff
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Patent number: 7226493Abstract: 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: GrantFiled: January 29, 2001Date of Patent: June 5, 2007Assignee: Elkem ASAInventors: Oystein Grong, Ole Svein Klevan
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Patent number: 7169207Abstract: 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: GrantFiled: October 3, 2003Date of Patent: January 30, 2007Assignees: Alcoa Inc., Elkem ASAInventors: Olaf Trygve Vegge, Jon Christian Brinch
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Publication number: 20060013721Abstract: 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: ApplicationFiled: September 8, 2004Publication date: January 19, 2006Applicant: ELKEM ASA NORWEIGAN CORPORATIONInventors: Georg Frommeyer, Karl Forwald, Gunnar Halvorsen, Kai Johansen, Oyvind Mikkelsen, Gunnar Schussler
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Publication number: 20050172864Abstract: 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: ApplicationFiled: April 24, 2003Publication date: August 11, 2005Applicant: Elkem ASAInventors: Eldar Dingsoyr, Magne Dastol, Cor Oldenziel, Bjorn Vassoy
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Patent number: 6861040Abstract: 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: GrantFiled: August 11, 2000Date of Patent: March 1, 2005Assignee: Elkem ASAInventors: Bruno Ceccaroli, Kenneth Friestad
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Patent number: 6849101Abstract: 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: GrantFiled: December 4, 2003Date of Patent: February 1, 2005Assignees: Alcoa Inc., Elkem ASA, Carnegie Mellon UniversityInventors: Richard J. Fruehan, Yun Li, Gerald Carkin
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Patent number: 6811677Abstract: 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: GrantFiled: May 16, 2003Date of Patent: November 2, 2004Assignee: Elkem ASAInventors: Jan Arthur Aune, Kai Johansen, Per Olav Nos
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Patent number: 6809144Abstract: 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: GrantFiled: June 11, 2001Date of Patent: October 26, 2004Assignees: Elkem ASA, Mondo Minerals OyInventors: Tore Danielssen, Anne Linnebo, Bjorn Sandelin
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Patent number: 6805723Abstract: 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: GrantFiled: March 6, 2003Date of Patent: October 19, 2004Assignees: Alcoa Inc., Elkem ASAInventors: Jan Arthur Aune, Kai Johansen
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Patent number: 6702994Abstract: 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: GrantFiled: September 7, 2001Date of Patent: March 9, 2004Assignee: Elkem ASAInventors: Knut Henriksen, Olaf Trygve Vegge
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Patent number: 6696035Abstract: 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: GrantFiled: July 3, 2001Date of Patent: February 24, 2004Assignee: Elkem ASAInventors: Magne Dastol, Halvard Tveit, Eldar Dingsoyr, Per Ronning, Svein Harsaker
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Patent number: 6635198Abstract: 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: GrantFiled: January 23, 2001Date of Patent: October 21, 2003Assignee: Elkem ASAInventors: Arnfinn Vatland, Olaf Trygve Vegge