Of Molten Metal Patents (Class 75/382)
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Patent number: 11808635Abstract: The present disclosure provides a system for continuously detecting the temperature and composition of molten steel during converter steelmaking, and relates to the technical field of steelmaking detection devices. A seating brick (3) and a probe conveying pipe (5) are provided on a side wall of a converter (1), and multiple probes are provided in different detection through holes (4) within the probe conveying pipe (5) respectively. The temperature of molten steel, the oxygen activity of the molten steel and the low carbon and phosphorus content in the molten steel within the converter can be detected in real time. This facilitates an operator adopting corresponding operational means to reach the smelting end point in an optimized manner so as to improve various economic and technical indexes in steelmaking.Type: GrantFiled: April 29, 2019Date of Patent: November 7, 2023Inventors: Chu Lien, Young Lian
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Patent number: 9701915Abstract: An object is to prevent blockage of a slag hole with char and slag, enabling stable operation of a gasification furnace. In a configuration in which a heat exchanger (20) is provided above a coal gasification portion (10), the diameters (D1, D3) of the slag hole (16) and the throat portion (17) are set to three times or more the pitch (ST) of rows of heat exchange tubes (21). By doing so, blockage of the slag hole (16) or the throat portion (17) with char and a sintered material (50) falling from the heat exchanger (20) is prevented, enabling stable operation of a coal gasification furnace (101).Type: GrantFiled: January 22, 2013Date of Patent: July 11, 2017Assignee: MITSUBISHI HITACHI POWER SYSTEMS, LTD.Inventors: Kenta Haari, Osamu Shinada, Yasunari Shibata, Yuichiro Kitagawa
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Patent number: 8728194Abstract: A method for controlling foamed slag in a stainless melt in an electric arc furnace. Slag level in the electric arc furnace is continuously detected thermographically as a function of time and slag level, and an addition of foaming material is controlled depending on the temperature and temperature gradient.Type: GrantFiled: August 7, 2009Date of Patent: May 20, 2014Assignee: SMS Siemag AGInventor: Johann Reichel
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Patent number: 8728196Abstract: A semi-liquid metal processing and sensing device comprising a crucible that is at least partially encircled by at least one induction coil. The one or more induction coils can be water cooled. The one or more induction coils can be designed to generate a variable power and/or variable frequency magnetic field which can be modulated to control the cooling of a molten metal charge in the crucible from the liquidus temperature to a selected heat content, resistivity and/or viscosity. The magnetic field can be designed to induce toroidal agitation of the metal charge in the crucible. The semi-liquid condition is sensed and can be actively controlled by the induction power supply via real time or non-real time analysis of electrical feedback signals that are obtained from the induction coil.Type: GrantFiled: May 22, 2012Date of Patent: May 20, 2014Assignee: Ajax TOCCO Magnethermic CorporationInventor: Alan A. Koch
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Publication number: 20130180361Abstract: A molten bath-based direct smelting process includes controlling the process conditions in a direct smelting vessel so that molten slag in a molten bath of metal and slag in the vessel has a viscosity in a range of 0.5-5 poise in an operating temperature range for the process.Type: ApplicationFiled: September 15, 2011Publication date: July 18, 2013Inventors: Rodney James Dry, Jacques Pilote
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Patent number: 8475561Abstract: A method for producing molten iron by melting an iron source material using an iron bath-type melting furnace comprising a top-blowing lance at an upper part of the furnace, a bottom-blowing tuyere in the bottom of the furnace and a tap hole at a lower part on the side of the furnace, the method comprising: a melting process of melting the iron source material, wherein the melting process has at least one tapping process of discharging the molten iron and the slag through the tap hole while holding a position of the furnace in generating the molten iron, and the tapping process continues or interrupts generation of the molten iron and continues top-blowing of the oxygen-containing gas to thereby keep a temperature of the molten iron in the furnace at or above a pre-set lowest temperature of the molten iron.Type: GrantFiled: March 24, 2009Date of Patent: July 2, 2013Assignee: Kobe Steel, Ltd.Inventors: Masataka Tateishi, Hiroshi Sugitatsu, Hideaki Fujimoto
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Patent number: 8241390Abstract: A semi-liquid metal processing and sensing device comprising a crucible that is at least partially encircled by at least one induction coil. The one or more induction coils can be water cooled. The one or more induction coils can be designed to generate a variable power and/or variable frequency magnetic field which can be modulated to control the cooling of a molten metal charge in the crucible from the liquidus temperature to a selected heat content, resistivity and/or viscosity. The magnetic field can be designed to induce toroidal agitation of the metal charge in the crucible. The semi-liquid condition is sensed and can be actively controlled by the induction power supply via real time or non-real time analysis of electrical feedback signals that are obtained from the induction coil.Type: GrantFiled: October 10, 2008Date of Patent: August 14, 2012Assignee: Ajax Tocco Magnethermic CorporationInventor: Alan A. Koch
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Publication number: 20110042031Abstract: A method for forming an object, including providing at least a first material having a melting point at a first temperature and a second material having a melting point at a second temperature; heating at least a portion of the first and second materials above the first and second temperatures to form a substantially molten alloy, the molten alloy having a solidifying point at a third temperature, the third temperature being less than the first temperature and the second temperature; and providing substantially solid further material to at least a portion of the molten alloy, the further material having a melting point at a temperature greater than the third temperature.Type: ApplicationFiled: August 21, 2009Publication date: February 24, 2011Inventors: Michael Thomas Furlong, Neil Hopkinson, Kamran Aamir Mumtaz
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Patent number: 7819940Abstract: For the production of stainless steel of the ferritic AISI 4xx group of steels, particularly the AISI 430 group of steels, based on liquid pig iron and FeCr solids, the invention proposes the use of the AOD (Argon Oxygen Decarburization) process in which oxygen and inert gas (inactive gas) together are blown into the bath through nozzles and top-blown onto the surface of the bath by a blowing lance. The aim of the treatment is to conclude a smelting charge within an optimal time period, to achieve the intended tapping temperature and composition, and to minimize chromium losses. This is achieved by a correspondingly applied technology and by means of a metallurgic process model which observes, prognosticates and controls the treatment of the smelting charge.Type: GrantFiled: November 11, 2005Date of Patent: October 26, 2010Assignee: SMS Siemag AktiengesellschaftInventor: Johann Reichel
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Publication number: 20100011908Abstract: A process for direct smelting metalliferous feed material in a direct smelting vessel and producing process outputs of molten metal, molten slag, and an off-gas from the vessel is disclosed. The process includes controlling pressure in the direct smelting vessel by controlling off-gas pressure in an off-gas stream supplied to a fluidised bed pretreatment apparatus while the process is operating in the “hold” and “idle” process states.Type: ApplicationFiled: April 24, 2007Publication date: January 21, 2010Inventor: John Neil Goodman
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Patent number: 7648551Abstract: Method and plant for pre-heating, transforming and melting a metal charge comprising metal scrap, in an electric arc furnace associated with a tunnel to transport, pre-heat and discharge the scrap. The furnace comprises a hearth and a roof through which the electrodes pass. The method provides that the furnace is weighed at least periodically in order to detect the quantity of discharged scrap present inside the furnace itself, that the temperature of the liquid bath inside the furnace is detected at least periodically and that at least the discharge delivery of the scrap inside the furnace is detected by weighing and is regulated in order to maintain the temperature of the liquid bath around a pre-determined value.Type: GrantFiled: November 25, 2004Date of Patent: January 19, 2010Assignee: Danieli & C. Officine Meccaniche SpAInventor: Romano Sellan
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Publication number: 20090285716Abstract: A manufacturing process for a remelt block containing aluminum designed for making aluminum alloy for the aircraft industry in which scrap containing mainly aluminum alloys used in the aircraft industry is supplied during a supply stage, the scrap is melted in a smelting furnace in order to obtain an initial molten metal bath during a smelting stage, the initial molten metal bath is subjected to purification by fractional crystallization in order to obtain a solidified mass and a bath of residual liquid during a segregation stage, and the solidified mass is recovered in order to obtain a remelt block during a recovery stage. The invention is particularly useful for the recycling of aluminum alloys used in the aircraft industry as it makes it possible to purify scrap of series 2XXX or series 7XXX alloys for iron and silicon, without eliminating additive elements such as zinc, copper and magnesium.Type: ApplicationFiled: June 18, 2007Publication date: November 19, 2009Applicant: ALCAN RHENALUInventors: Jean-Francois Verdier, Jean-Remi Butruille, Michel Leroy, Didier Valax
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Patent number: 7211127Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.Type: GrantFiled: June 9, 2005Date of Patent: May 1, 2007Assignee: Nucor CorporationInventors: Rama Mahapatra, Walter Blejde, Joel Sommer, Scott Story, Dave Sosinsky
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Patent number: 6921425Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.Type: GrantFiled: July 8, 2004Date of Patent: July 26, 2005Assignee: Nucor CorporationInventors: Walter N. Blejde, Joel Sommer
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Patent number: 6830606Abstract: The present invention: solves the problems of hitherto disclosed technologies, such as insufficient suppression of the oxidation loss of [Cr] and the excessive erosion of refractories, in the decarburization-refining of chromium-contained molten steel under a normal or reduced pressure; and is characterized by: determining, in sequence; a molten steel temperature during the refining through actual measurement or computation from a molten steel temperature before the refining and refining conditions; [C] and [Cr] concentrations during the refining through actual measurement or computation from molten steel components before the refining and refining conditions; a CO partial pressure PCO in an atmosphere during the refining from the total pressure P of the atmosphere, an oxygen gas supply rate and an inert gas supply rate, a Hilty's equilibrium temperature TH from said [C] and [Cr] concentrations and PCO; the difference &Dgr;T between said molten steel tempType: GrantFiled: December 30, 2003Date of Patent: December 14, 2004Assignee: Nippon Steel CorporationInventors: Ryuji Nakao, Tomoaki Tanaka, Masao Igarashi, Koichiro Yoshino
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Publication number: 20040244532Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.Type: ApplicationFiled: July 8, 2004Publication date: December 9, 2004Inventors: Walter N. Blejde, Joel Sommer
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Patent number: 6808550Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.Type: GrantFiled: February 15, 2002Date of Patent: October 26, 2004Assignee: Nucor CorporationInventors: Rama Mahapatra, Walter Blejde, Joel Sommer, Scott Story, Dave Sosinsky
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Publication number: 20040182203Abstract: The present invention: solves the problems of hitherto disclosed technologies, such as insufficient suppression of the oxidation loss of [Cr] and the excessive erosion of refractories, in the decarburization-refining of chromium-contained molten steel under a normal or reduced pressure; and is characterized by: determining, in sequence; a molten steel temperature during the refining through actual measurement or computation from a molten steel temperature before the refining and refining conditions; [C] and [Cr] concentrations during the refining through actual measurement or computation from molten steel components before the refining and refining conditions; a CO partial pressure PCO in an atmosphere during the refining from the total pressure P of the atmosphere, an oxygen gas supply rate and an inert gas supply rate; a Hilty's equilibrium temperature TH from said [C] and [Cr] concentrations and PCO; the difference &Dgr;T between said molten steel temperatuType: ApplicationFiled: December 30, 2003Publication date: September 23, 2004Inventors: Ryuji Nakao, Tomoaki Tanaka, Masao Igarashi, Koichiro Yoshino
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Patent number: 6607577Abstract: A method and computer program for determining the amounts of desulphurizing reagents required to reduce the sulphur content in hot metal to meet a specified aim concentration. The determination of the amounts of reagents is based on a multivariate statistical model of the process. This model is initially based on a set of representative data from the process including all process parameters for which data are available. These parameters include chemistry-type variables and variables representing the state of operation of the desulphurization process. The use of a plurality of process and chemistry variables provides a more advantageous determination of the reagent quantities. Also, the method includes an adaptation scheme whereby new data are used to automatically update the predictive model so that the optimality of the model is maintained. Other features of the system include optimal handling of missing data, and data and model validation schemes.Type: GrantFiled: August 13, 2001Date of Patent: August 19, 2003Assignee: Dofasco Inc.Inventors: Vit Vaculik, Shannon L. Quinn, Michael S. Dudzic
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Patent number: 6604016Abstract: A sampling device for thermal analysis of solidifying metal, comprising at least one container intended to contain a sample quantity (30) of liquid metal during analysis, and at least one sensor (40, 220, 240) for thermal analysis, said sensor(s) being intended to be at least partly immersed in the solidifying metal sample quantity during analysis. The container comprises an inner wall (50), with an interior surface (60) intended to face the sample quantity during analysis, and an exterior surface (70); an outer wall (80), with an exterior surface (100) intended to face the ambient atmosphere, and an interior surface (90); said walls being joined at the mouth of the container whereby the exterior surface (70) of the inner wall (50) and the interior surface (90) of the outer wall (80) together define an essentially closed space (110).Type: GrantFiled: May 2, 2000Date of Patent: August 5, 2003Assignee: SinterCast ABInventor: Conny Andersson
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Patent number: 6596995Abstract: Provided are methods and apparatuses for the sensing of a property of a molten metal that lies beneath layers of interfering matter. A stream of gas is propelled into the layers of interfering matter at a velocity that is sufficient for the gas to penetrate through the layers of interfering matter and into the molten metal, thereby providing an opening through the layers of interfering matter. At the same time, energy emanating from the molten metal is detected and measured through the opening, so as to obtain an energy measurement. Then, the energy measurement is processed to determine a value for the desired property of the molten metal.Type: GrantFiled: March 7, 2002Date of Patent: July 22, 2003Inventor: Manfred Bender
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Patent number: 6500224Abstract: The invention is directed to a method for operating a steelmaking furnace including the steps of charging steelmaking materials into the steelmaking furnace, blowing oxygen into the steelmaking furnace, discontinuing the oxygen blow when the charged steelmaking materials are reduced to a liquid steel product, determining the temperature of the finished liquid steel product, blowing a nitrogen gas coolant into the steelmaking furnace to reduce the temperature of the finished liquid steel product to an aim tapping temperature, discontinuing the nitrogen gas coolant blow when the finished liquid steel product temperature is lowered to the aim tapping temperature, and tapping the finished liquid steel product at the aim tapping temperature for downstream processing.Type: GrantFiled: October 11, 2001Date of Patent: December 31, 2002Assignee: Bethlehem Steel CorporationInventors: Carl F. Orrling, Daniel Goldstein
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Patent number: 6302941Abstract: A method for producing a molten iron in a blast furnace comprises the steps of: preparing an optical fiber covered with a metallic tube; measuring a temperature of the molten iron flow discharged from a tap hole of the blast furnace by means of making use of a metallic tube covered by the optical fiber to obtain an information of the temperature of the molten iron; and controlling a heat conditions of the blast furnace, based on the obtained information of the temperature of the molten iron. Controlling a heat conditions is achieved by using a heat conditions estimation model, and by inferring a level and a transition of the heat conditions in the furnace.Type: GrantFiled: April 24, 2000Date of Patent: October 16, 2001Assignee: NKK CorporationInventors: Kenji Oya, Shigeru Wakita, Yasukazu Hayasaka, Hajime Wakai
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Patent number: 6171364Abstract: A process of producing molten iron involves: a) introducing iron oxide, flux, oxygen, nitrogen, carbon, and hydrogen to a smelter reactor; b) maintaining conditions to cause (i) the iron oxide to be reduced, (ii) molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of foaming, FeO-containing slag, and (iii) carbon monoxide gas to rise through the slag; c) causing at least some of the carbon monoxide to react with the oxygen; d) releasing an offgas containing CO, CO2, H2, and H2O; and e) removing at least some of the molten iron and slag from the reactor. Good process stability is achieved by: f) repeatedly measuring, during the process, the conditions of the slag height, the temperature of the molten iron, the levels of CO, CO2, H2, and H2O in the offgas, the carbon level in the molten iron, and the FeO level in the slag, and g) subsequently adjusting one or more process variables (e.g.Type: GrantFiled: March 21, 1997Date of Patent: January 9, 2001Assignee: Steel Technology CorporationInventors: Balu Sarma, Kenneth B. Downing
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Patent number: 6102981Abstract: A method for controlling the composition of a cast iron melt is presented. A cast iron melt is prepared which has added to it a structure modifying agent and a nucleating agent in amounts selected to produce a fully compacted graphite iron upon solidification of the melt. A sample vessel, having an inner wall having an active portion coated with a material which will lower the concentration of dissolved modifying agent and an inert portion, is used to extract a sample of the melt. Three temperature measuring devices are used to measure temperatures at three locations within the melt. One measuring device measures the temperature at the center of the vessel, one measures the temperature at the inert portion of the vessel's inner surface and one measures the temperature at the active portion of the vessel's inner surface. In another aspect of the invention, two sample vessels are used, one having an active surface and the other having an inert surface.Type: GrantFiled: September 16, 1998Date of Patent: August 15, 2000Assignee: SinterCast ABInventor: Ragnar Lindholm
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Patent number: 6042632Abstract: Solidified copper matte is used as a coolant to moderate or reduce the temperature of a bath of molten blister copper resident within a continuous, top-blown converter. In one embodiment, the addition of solidified copper matte to a bath of molten blister copper resident within a continuous, top-blown converter increases the throughput of the converter.Type: GrantFiled: September 24, 1997Date of Patent: March 28, 2000Assignee: Kennecott Holdings CompanyInventor: David B. George
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Patent number: 6004504Abstract: A method and apparatus for improved control of continuous electric arc furnace steelmaking in which a charge velocity detector measures charge velocity of metallic charge introduced to the furnace. A charge mass detector measures a charge mass of metallic charge introduced to the furnace. A computer determines a feed rate based on the charge velocity and the charge mass. An automatic bath level probe detects a steel bath. The computer determines a steel bath level and optimal positions to insert a temperature probe and an oxygen lance, and further predicts new bath levels from one tapping time to the next tapping time. The temperature probe is inserted to an optimal measurement position based on the steel bath level and measures a steel bath temperature. The oxygen lance is positioned and maintained at an optimal oxygen injection position and injects oxygen into the bath.Type: GrantFiled: March 12, 1998Date of Patent: December 21, 1999Assignee: Techint Compagnia Tecnica InternazionaleInventor: John A. Vallomy
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Patent number: 5885322Abstract: A process of smelting iron that comprises the steps of:a) introducing a source of iron oxide, oxygen, nitrogen, and a source of carbonaceous fuel to a smelting reactor, at least some of said oxygen being continuously introduced through an overhead lance;b) maintaining conditions in said reactor to cause (i) at least some of the iron oxide to be chemically reduced, (ii) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (iii) carbon monoxide gas to rise through the slag;c) causing at least some of said carbon monoxide to react in the reactor with the incoming oxygen, thereby generating heat for reactions taking place in the reactor; andd) releasing from the reactor an offgas effluent,is run in a way that keeps iron losses in the offgas relatively low. After start-up of the process is complete, steps (a) and (b) are controlled so as to:e) keep the temperature of the molten iron at or below about 1550.degree. C.Type: GrantFiled: March 21, 1997Date of Patent: March 23, 1999Assignee: Steel Technology CorporationInventors: Balu Sarma, Kenneth B. Downing
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Patent number: 5762682Abstract: In steel-making, there are conflicting processing requirements at different stages of the process. The method and apparatus of the invention creates different processing conditions at different stages of the process. Molten ferrous material (2) is stirred by bubbling a gas therethrough. A refractory ring (10) is first partially immersed in the molten steel within a substantially slag free portion of the surface of the molten ferrous metal to form a bounded substantially slag-free area. The molten steel is then heated by the introduction of exothermically reacting heating agents such as aluminium and oxygen through an oxygen gas line (7) and an aluminium delivery tube (9), respectively. The refractory ring (10) is then removed from the molten steel when the steel has reached a predetermined temperature and air is then excluded from the volume above the molten steel by placing a hood (16) over the ladle containing the molten steel. Sulphur is then removed from the steel.Type: GrantFiled: August 21, 1995Date of Patent: June 9, 1998Assignee: Vacmetal LimitedInventor: John Rushe
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Patent number: 5755889Abstract: Apparatus and a method for recovering solder from dross. Dross is poured into a heated chamber (1). The heated dross is then compressed by a piston (21) to force good solder out of the dross into a collecting tray (17).Type: GrantFiled: November 29, 1995Date of Patent: May 26, 1998Assignee: Apple House Elecronics Ltd.Inventor: Stephen Anthony Johnson
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Patent number: 5567222Abstract: A method of controlling slag coating in a steel converter in which slag is left in the converter after tapping, and a slag solidifying agent is added to the slag to form a coated slag which is used to coat the bottom and/or side wall surface of the converter. The method is performed bya) examining the composition of the slag at the tapping time;b) determining, based on the examined slag and through an equilibrium calculation using thermodynamic data, the amount of solidifying agent per unit weight of the slag necessary for maintaining the liquid volume fraction of the coated slag to a value not greater than about 40% at the planned tapping temperature of the next charge of steel;c) determining the amount of charge of the solidifying agent based on the calculated required amount of the solidifying agent and the amount of the slag remaining in the converter; andd) adding the calculated charge of the solidifying agent to the slag after tapping, to form a coated slag.Type: GrantFiled: March 21, 1995Date of Patent: October 22, 1996Assignee: Kawasaki Steel CorporationInventors: Katsunori Takahashi, Eizo Maeda, Hajime Suzuki, Sumio Yamada, Taichi Nakazawa, Yasuo Imaiida
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Patent number: 5542963Abstract: The process of the invention comprises gaseous reduction of iron oxides in solid state combined with concurrent melting of the hot reduced iron within a closed system without cooling down the charge or exposing it to the outside atmosphere. It incorporates the continuous recycling of a major portion of the off-gases from reduction, and fully utilizes the chemical heat contained in the fuel and reductant by substantially complete oxidation to CO.sub.2 and H.sub.2 O in the system gaseous reaction products and recovery of their sensible heat, prior to final exhaustion as waste gases. Features include dewatering of the off-gas from reduction, enriching with hydrocarbon and recycling a major portion, and separately combusting a minor portion for transfer of the sensible heat to the enriched major portion, and also usually the combustion of a second minor portion with oxygen as fuel for melting, with the sensible heat of these combustion products also utilized for heating the enriched and recycled portion.Type: GrantFiled: September 21, 1994Date of Patent: August 6, 1996Inventor: William L. Sherwood
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Patent number: 5015287Abstract: A steel melting and secondary-refining method comprising the steps of: melting steel manufacture raw materials while the molten steel is subjected to oxidation and decarburization so that the oxidation and decarburization are substantially completed before melt-down; after melt-down, heating the molten steel to a temperature above a liquidus line temperature and below 50.degree. C. in temperature increment from the liquidus line temperature, and thereafter tapping the molten steel into a primary ladle; teeming the molten steel from the primary ladle into a secondary refining furnace; allowing the molten steel to be effluent into a secondary ladle at a lower portion of the secondary refining furnace while the temperature of the molten steel is raised; and continuously performing gas bubbling in the secondary ladle in a vacuum under existence of slag simultaneously with the effluence of the molten steel into the secondary ladle.Type: GrantFiled: July 25, 1989Date of Patent: May 14, 1991Assignee: Sumitomo Electric Industries, Ltd.Inventors: Katsuhiko Yamada, Norio Egusa
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Patent number: 4976780Abstract: Inference is carried out through intermediate hypotheses representing physical states of a blast furnace using HG (Heuristic Grade) in order to comprehensively diagnose the state of the furnace to ascertain optimum actions. Specific parameters are monitored to immediately recognize a transition of conditions inside the furnace to additionally execute the inference. Various types of actions such as defensive actions and offensive actions are covered in this inference. A burden distribution estimation model considering collapse of a coke bed is used for calculating distribution inside the furnace to aid in deciding on an optimum action when an action to alter distribution in the furnace is required as the result of the inference. Creation and alteration of a knowledge base for the inference are carried out without interrupting the inference.Type: GrantFiled: December 14, 1989Date of Patent: December 11, 1990Assignee: Nippon Steel CorporationInventors: Shigeru Amano, Tsuyoshi Takarabe, Hiroshi Oda, Takashi Nakamori, Satoshi Watanabe, Masamichi Taira
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Patent number: 4963186Abstract: Disclosed herein is a method for operating blast furnace, wherein, when charging coke and ore alternately from the furnace top to form alternate coke and ore layers for operation of a blast furnace, a coke layer is formed by charging coke of properties especially suitable for improvement of gas and liquid permeability of the coke layer to the central part thereof or an ore layer is formed by charging ordinary versatile type coke to the central part of the ore layer prior to formation thereof. The centrally charged coke forms a major part of the dead coke layer which is sequentially renewed under the cohesive zone of the blast furnace to maintain appropriate gas and liquid permeability of the dead coke layer, thereby enhancing the production efficiency and stability of the blast furnace operation while suppressing erosive wear of refractory walls of the furnace.Type: GrantFiled: September 2, 1988Date of Patent: October 16, 1990Assignee: Kabushiki Kaisha Kobe Seiko ShoInventors: Masataka Shimizu, Ryuichi Hori, Yoshio Kimura, Fumio Noma, Mitsutoshi Isobe, Tsunao Kamijo, Shinichi Inaba