Purifying Acid Or Reactant Patents (Class 423/531)
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Patent number: 10640376Abstract: Sulfur trioxide is produced from a feed stream comprising sulfur-containing compounds and dissolved metals, such as alkali metals, in a plant comprising an incineration furnace, a waste heat boiler, a dilution air heater, a dust removal absorber and an SO2 converter. The plant may further comprise a sulfuric acid condenser for the production of sulfuric acid.Type: GrantFiled: July 4, 2017Date of Patent: May 5, 2020Assignee: Haldor Topsoe A/SInventors: Morten Thellefsen, Martin Møllerhøj
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Patent number: 9156716Abstract: A method for the purification of spent sulfuric acid and particularly the purification of spent acid, from titanium dioxide rutile manufacture through a chloride route, is provided. In the chloride route of titanium dioxide manufacture, sulfuric acid is used to clean the un-reacted gaseous flow coming out of the oxidizer, so the spent acid mainly contains un-reacted Ti4+ ions, trace amounts of Fe3+ ions, and NO2 gas. Titanium phosphate can be precipitated using acidic and or alkaline phosphate-containing precipitants in stoichiometric amounts. The method can include the addition of cutting water. NO2 gas evolved during the reaction can be scrubbed in water. The resulting aqueous acid-rich portion, or supernatant, can be separated from the precipitated phosphates and is very clear. Evaporation under vacuum conditions can increase the sulfuric acid concentration. The resultant purified acid can be re-used.Type: GrantFiled: January 8, 2015Date of Patent: October 13, 2015Assignee: The National Titaniun Dioxide Co., Ltd. (CRISTAL)Inventors: Ahmed Yasir Vakayil, Rene Jongen, Ahmad I. Jomha
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Patent number: 8906133Abstract: A process for cooling an acid that is withdrawn from an absorption apparatus of a sulfuric acid plant includes pumping the acid to be cooled from an acid pump tank and supplying the acid to a shell space of a heat exchanger. Water is supplied as a heat transport medium to heat transfer elements disposed in the shell space so as to at least partially convert, by heat transfer from the acid, the water to steam. The acid which was cooled in the heat exchanger is supplied back to the absorption apparatus. The water is separated from the steam in a steam drum. The separated water is recirculated to the heat exchanger using a pump.Type: GrantFiled: January 11, 2011Date of Patent: December 9, 2014Assignee: Outotec OyjInventors: Karl-Heinz Daum, Wolfram Schalk
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Patent number: 8815202Abstract: A process for producing sulfuric acid with reduced levels of nitrogen oxides (NOx) within a typical sulfuric acid production line. A hydrazine source material can be mixed with a sulfuric acid effluent at a temperature of at least about 90° C. for a period of at least 1 minute to reduce the level of NOx is the sulfuric acid effluent.Type: GrantFiled: August 19, 2013Date of Patent: August 26, 2014Assignee: E I du Pont de Nemours and CompanyInventors: Hasan Dindi, Donald James Loftus
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Patent number: 8772565Abstract: A radioactive waste acid is recycled. The waste acid is a fluoboric waste acid. The waste acid contains a lot of oxides and radioactive nuclei. The waste fluoboric acid is processed to obtain a purified fluoboric acid. The amount of radioactive nuclei is greatly reduced. Thus, the present invention has a simple procedure with low cost and reduced power consumption.Type: GrantFiled: July 3, 2013Date of Patent: July 8, 2014Assignee: Institute of Nuclear Energy Research, Atomic Energy CouncilInventors: Chin-Hsiang Kan, Wen-Cheng Lee, Tsong-Yang Wei
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Patent number: 8709376Abstract: Disclosed is a process for the extractive recovery of an acid catalyst from an aqueous mixture of glycolic acid with an extraction solvent comprising a tertiary amine or an onium carboxylate compound, a modifier, and a diluent. The acid catalyst, which can comprise strong acids such as sulfuric acid, alkyl sulfonic acids, and fluoroalkyl sulfonic acids, can be recovered by back extraction with aqueous formaldehyde and recycled to a process for the preparation of glycolic acid by the acid-catalyzed carbonylation of formaldehyde.Type: GrantFiled: September 23, 2010Date of Patent: April 29, 2014Assignee: Eastman Chemical CompanyInventors: Scott Donald Barnicki, Stephen Neal Falling, Jeffrey Scott Kanel, Robert Sterling Kline, Peter Borden Mackenzie
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Publication number: 20140056802Abstract: A process for producing sulfuric acid with reduced levels of nitrogen oxides (NOx) within a typical sulfuric acid production line. A hydrazine source material can be mixed with a sulfuric acid effluent at a temperature of at least about 90° C. for a period of at least 1 minute to reduce the level of NOx is the sulfuric acid effluent.Type: ApplicationFiled: August 19, 2013Publication date: February 27, 2014Applicant: E I DU PONT DE NEMOURS AND COMPANYInventors: Hasan Dindi, Donald James Loftus
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Patent number: 8603420Abstract: The invention enables processing waste sludge after galvanic treatment of metals, and particularly recycling spent pickling acids after pickling. Provided is an environmentally friendly process, which yields acids for reuse, and pure nano-sized iron pigments as a side product.Type: GrantFiled: September 7, 2010Date of Patent: December 10, 2013Assignee: Green Future Ltd.Inventors: Vladimir Boiko, Reuben Schapiro
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Publication number: 20130302240Abstract: A method for the purification of spent sulfuric acid and particularly the purification of spent acid, from titanium dioxide rutile manufacture through a chloride route, is provided. In the chloride route of titanium dioxide manufacture, sulfuric acid is used to clean the un-reacted gaseous flow coming out of the oxidizer, so the spent acid mainly contains un-reacted Ti4+ ions, trace amounts of Fe3+ ions, and NO2 gas. Titanium phosphate can be precipitated using acidic and or alkaline phosphate-containing precipitants in stoichiometric amounts. The method can include the addition of cutting water to commence the precipitation in two or more steps, when an acidic precipitant is used, and in one step with half the volume of water when an alkaline precipitant is used.Type: ApplicationFiled: May 10, 2012Publication date: November 14, 2013Applicant: THE NATIONAL TITANIUM DIOXIDE CO. LTD. (CRISTAL)Inventors: Ahmed Yasir VAKAYIL, Rene JONGEN, Ahmad I. JOMHA
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Publication number: 20120301389Abstract: The present invention provides an organic phase composition comprising (a) a first solvent (S1) characterized by water solubility of less than 10% and by at least one of (a1) having a polarity related component of Hoy's cohesion parameter (delta-P) between 5 and 10 MPa1/2 and (b1) having a Hydrogen bonding related component of Hoy's cohesion parameter (delta-H) between 5 and 20 MPa1/2; (b) a second solvent (S2) characterized by a water solubility of at least 30% and by at least one of (a2) having delta-P greater than 8 MPa1/2 and (b2) having delta-H greater than 12 MPa1/2; (c) water; (d) a non-volatile strong acid; and (e) a salt thereof.Type: ApplicationFiled: February 6, 2011Publication date: November 29, 2012Applicants: ASHER VITNER LTD., EYAL RESEARCH CONSULTANTS LTD.Inventors: Aharon Eyal, Asher Vitner, Revital Mali, Carmi Raz
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Publication number: 20110129410Abstract: “METHOD FOR RECYCLING USED LEAD ACID BATTERIES ELECTROLYTIC SOLUTION”, especially the automotive batteries, has the following stages: the sulfuric acid solution derived from the cutting of batteries goes through a drying bed (quick filters) which is composed of a layer of crushed rocks, “bidim” and sand or through a press filter for the retaining of the solid particles, after the solution goes through these filters, it goes through to a reactor where it suffers a forced decantation process for retaining the heavy metals and contaminants; the forced decantation process is carried out by adding 20 liters of aluminum dioxide, 20 kilos of lime (in the form of milk of lime), 2 liters of aluminum polychloride (flocculent) and 200 grams of acrylic acid acrylamide (polymer, used diluted in water) to every 10,000 liters of sulfuric acid under shaking, it is then left at rest for 40 minutes for decantation, soon after decantation the floating part goes through a bag filter with a polyethylene sheet filter and then throType: ApplicationFiled: May 27, 2009Publication date: June 2, 2011Inventor: Almir Dos Santos Trindade
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Patent number: 7842272Abstract: Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.Type: GrantFiled: October 6, 2006Date of Patent: November 30, 2010Assignee: Wacker Chemie AGInventors: Klaus Kaeppler, Reinhold Iretzberger, Gerhard Nagy
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Publication number: 20100284900Abstract: A method for recovering sulfuric acid from concentrated acid hydrolysate of plant cellulose material is disclosed. In some of the examples, the concentrated acid hydrolysate is mixed with a liquid organic precipitant, thereby the sugars in the hydrolysate is precipitated and separated out, and the remained is sulfuric acid and an organic solvent solution. Then the organic solvent is separated by distillation or extraction, thereby obtaining the pure sulfuric acid solution. This precipitation method can recover above 90% sugars and acids with a small amount of organic precipitant, which greatly reduces the recover cost.Type: ApplicationFiled: July 29, 2008Publication date: November 11, 2010Inventor: Peihao Chen
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Publication number: 20100152517Abstract: A process for the regeneration of spent sulfuric acid including contacting spent sulfuric acid containing acid soluble oils (ASO) with sulfur dioxide to extract at least a portion of the ASO from the spent sulfuric acid into the sulfur dioxide. The sulfuric acid phase having a reduced ASO content and a sulfur dioxide phase containing at least a portion of the ASO may be recovered. The resulting sulfuric acid and sulfur dioxide phases may be further separated to recover ASO, sulfur dioxide, and sulfuric acid.Type: ApplicationFiled: December 12, 2008Publication date: June 17, 2010Applicant: CATALYTIC DISTILLATION TECHNOLOGIESInventor: William M. Cross, JR.
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Patent number: 7682066Abstract: The recycling apparatus of waste sulfuric acid for collecting waste sulfuric acid generated at a source site A, transporting it by a carrier B, and recycling it for reuse at a user site C, the recycling apparatus of waste sulfuric acid including a receiving tank for receiving virgin sulfuric acid (a) and waste sulfuric acid (b) having a concentration different from that of the virgin sulfuric acid, and including (1) a mixer alone, (2) a mixer and a concentration monitor, or a mixer and a cooler in combination, or (3) a mixer, a concentration monitor, and a cooler in combination.Type: GrantFiled: November 28, 2003Date of Patent: March 23, 2010Assignee: Sony CorporationInventor: Yasuhito Inagaki
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Publication number: 20100015035Abstract: The invention relates to a method of producing sulfuric acid wherein an SO2-containing raw gas produced in a sulfuric-acid recovery plant is passed through at least one reactor in which a catalytic reaction of SO2 to SO3 takes place, and the SO3 thereby formed is converted into sulfuric acid. According to the invention, at least a partial stream of the gas stream leaving the sulfuric-acid recovery plant is hydrogenated with an H2-rich gas in a post-treatment stage. The H2S-containing gas stream formed by the hydrogenation is fed into the H2S gas scrubber of a coke oven plant or a petrochemical plant. The invention also relates to an installation for carrying out the method.Type: ApplicationFiled: March 20, 2008Publication date: January 21, 2010Inventor: Holger Thielert
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Publication number: 20090317321Abstract: Spent sulfuric acid is decomposed by atomizing it with an oxygen-containing stream into a decomposition furnace.Type: ApplicationFiled: June 18, 2008Publication date: December 24, 2009Inventors: James Patrick Meagher, William Thoru Kobayashi, Maynard Guotsuen Ding, Lee Jonathan Rosen
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Patent number: 7595035Abstract: Process for the recovery of sulfuric acid comprising: (a) contacting a stream containing sulfuric acid vapor and/or sulfur trioxide in an absorption stage with a ionic liquid absorbent, (b) withdrawing a gas substantially free of sulfuric acid vapor and/or sulfur trioxide from said absorption stage, (c) withdrawing a stream comprising the ionic liquid absorbent from said absorption stage, in which said ionic liquid absorbent contains sulfuric acid, (d) recovering sulfuric acid from said ionic liquid absorbent by passing the stream of step (c) through a separation stage, (e) withdrawing from the separation stage (d) a stream rich in sulfuric acid, (f) withdrawing from the separating step (d) a ionic liquid absorbent stream in which said ionic liquid absorbent contains sulfuric acid and returning said stream to the absorption step (a).Type: GrantFiled: June 4, 2007Date of Patent: September 29, 2009Assignee: Haldor Topsoe A/SInventors: Sven Ivar Hommeltoft, Morten Thellefsen
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Publication number: 20090226351Abstract: A supercritical oxidation process, which comprises pressurizing and heating an aqueous system to form a fluid phase under supercritical conditions, feeding an oxidizer into said fluid phase to cause an oxidation reaction therein, directing the resultant fluid reaction phase into a central region of a cooling chamber while providing a coolant in an internal peripheral region of said cooling chamber, said peripheral region being adjacent to the inner surface of the cooling chamber, mixing the fluid reaction phase with said coolant within the cooling chamber, removing the reaction mixture from said cooling chamber and subsequently further reducing the temperature and the pressure of said reaction mixture to obtain a product mixture.Type: ApplicationFiled: February 6, 2007Publication date: September 10, 2009Inventor: Ariel Rosenberg
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Patent number: 7537749Abstract: The invention concerns a method for processing heavy metal-laden spent sulfuric acid. For this, iron-laden spent sulfuric acid or iron-laden sulfuric materials obtained therefrom are reacted with a material that contains iron chloride and optionally other metal chlorides, producing iron (II) sulfate. The spent sulfuric acid preferably derives from titanium dioxide production.Type: GrantFiled: October 1, 2004Date of Patent: May 26, 2009Assignee: Tronox Pigments GmbHInventors: Gerhard Auer, Berndt-Ullrich Köhler, Benno Laubach
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Patent number: 7498007Abstract: A process for recovery of vanadium dissolved in acid solutions or liquors by precipitating it out as vanadium pentoxide. Separation is carried out by adding calcium hydroxide, quicklime or calcium carbonate to the acid solution or liquor, producing a precipitate of vanadium pentoxide, which is separated from the liquid by physical methods such as filtration or centrifugation. If the acid is other than sulfuric acid, the calcium which remains dissolved in the solution or liquor by the addition of calcium hydroxide, quicklime or calcium carbonate, is removed by adding sulfuric acid, to produce solid calcium sulfate and water. The calcium sulfate is extracted from the solution or liquor or liquor by filtration or centrifugation. With sulfuric acid solution or liquors, after addition of the neutralizing agent, a solid precipitate of vanadium pentoxide and calcium sulfate is formed, which is then separated from the solution or liquor.Type: GrantFiled: March 16, 2005Date of Patent: March 3, 2009Inventors: Benjamin Scharifker, Rossana Arenare
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Patent number: 7473409Abstract: A recycling process is presented to treat spent waste acid solutions whereby useful products are produced. Spent waste acid containing inorganic and organic contaminants is mixed with a magnesium compound containing aluminum and iron compounds that form oxyhydroxide flocs that complex, react, sequester and/or co-precipate the contaminates from the admixture. The magnesium reacts with sulfate ions to form a high quality magnesium sulfate solution.Type: GrantFiled: August 30, 2006Date of Patent: January 6, 2009Assignee: Veolia ES Technical Solutions L.L.C.Inventor: Danny Mislenkov
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Publication number: 20080293979Abstract: Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.Type: ApplicationFiled: October 6, 2006Publication date: November 27, 2008Applicant: WACKER CHEMIE AGInventors: Klaus Kaeppler, Reinhold Iretzberger, Gerhard Nagy
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Patent number: 7452521Abstract: This invention relates to a method for removing mercury from dilute sulphuric acid. According to the method sulphuric acid solution is scrubbed with an aqueous solution containing thiosulphate, which precipitates the mercury present in the sulphuric acid solution either as mercury sulphide or, in a chlorine-containing environment, as a mercury sulphide-mercury chloride double salt. The quantity of thiosulphate to be fed is adjusted so that it precipitates the mercury in the sulphuric acid solution, but still does not form elemental sulphur.Type: GrantFiled: July 16, 2004Date of Patent: November 18, 2008Assignee: Outotec OYJInventors: Dag Berg, Jens Nyberg, Aija Rytioja, Heljä Peltola, Pekka Taskinen
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Patent number: 7442359Abstract: The invention is directed to a process for the recovery of sulphuric acid from a mixture comprising sulphuric acid and hydrocarbons, in particular carbohydrates. In accordance with the present invention the mixture comprising sulphuric acid and carbohydrates, is contacted with an anion selective membrane, thus producing a sulphuric acid rich filtrate stream and a stream depleted in sulphuric acid.Type: GrantFiled: August 10, 2007Date of Patent: October 28, 2008Assignee: Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek TNOInventors: Johannes Wouterus Van Groenestijn, Jacob Hendrik Obbo Hazewinkel, Raymond Johannes Maria Creusen, Koen Peter Henri Meesters
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Publication number: 20080175777Abstract: The present invention provides for process for inhibiting the levels of nitrogen oxides in process gas streams from sulfuric acid regeneration and production plants. The process gas stream from the waste heat boiler and the candle mist eliminator is contacted with ozone which will react with nitrogen oxides present in the flue gas.Type: ApplicationFiled: January 10, 2008Publication date: July 24, 2008Inventors: Naresh Suchak, Steven Joseph Finley, Joseph A. Eschbach, Robert Zeiss
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Patent number: 7360550Abstract: A system for recycling spent sulfuric acid, wherein spent sulfuric acid is effectively utilized at a place other than a discharge source regardless of geographical conditions, and a method for recycling waste sulfuric acid. In the system, when spent sulfuric acid that is discharged or collected at a discharge source is transported by a carrier unit and used at a user office a concentration of the spent sulfuric acid is measured and/or adjusted at least at one of the discharge source, the carrier unit, and the user office. The spent sulfuric acid waste liquid that is discharged or collected at the discharge source is reutilized by being mixed with at least one of a hydrogen peroxide solution and water.Type: GrantFiled: April 4, 2003Date of Patent: April 22, 2008Assignee: Sony CorporationInventor: Yasuhito Inagaki
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Patent number: 7351391Abstract: A system and method of economically converting a spent first pickling acid solution that contains hydrochloric acid, water and ferrous chloride into a suitable second pickling solution. Sulfuric acid is added to the first pickling acid solution. This produces a regeneration solution. In the regeneration solution, the sulfuric acid reacts with said ferrous chloride and water to produce ferrous sulfate heptahydrate and hydrochloric acid. The regeneration solution is cooled to promote precipitation of the ferrous sulfate heptahydrate from the regeneration solution, therein creating ferrous sulfate heptahydrate crystals and a second pickling acid solution. The second pickling acid solution contains both hydrochloric acid and sulfuric acid. The ferrous sulfate heptahydrate crystals are separated from second pickling solution. The ferrous sulfate heptahydrate is sold commercially and the second pickling acid solution is used to directly pickle ferrous metal.Type: GrantFiled: May 16, 2005Date of Patent: April 1, 2008Inventors: Douglas R. Olsen, Charles D. Blumenschein
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Patent number: 7344692Abstract: A process for the regeneration of sulfuric acid contaminated with hydrocarbons and water to produce pure concentration acid comprising: contacting sulfuric acid contaminated with hydrocarbons and water with oxygen and elemental sulfur in the presence of a vanadium containing catalyst in a reaction zone, maintaining at least a portion of the acid in the liquid phase, converting hydrocarbon to carbon oxides and water, and converting sulfur and sulfurdioxide to sulfurtrioxide, separating the reactor effluent into a vapor stream and a liquid stream and cooling and partially condensing of the vapor stream to concentrate clean acid.Type: GrantFiled: December 14, 2005Date of Patent: March 18, 2008Assignee: Catalytic Distillation TechnologiesInventors: Lawrence A. Smith, Jr., Abraham P. Gelbein
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Publication number: 20080063593Abstract: A process for the regeneration of spent sulfuric acid comprises decomposing the spent sulfuric acid to SO2, a reducing agent, such as hydrocarbon and water, preferably in a thin film on a solid surface in the presence of a hydrocarbon reducing agent. The SO2 generated in the decomposition step is converted to SO3 in the presence of water and concentrated sulfuric acid is condensed out.Type: ApplicationFiled: September 8, 2006Publication date: March 13, 2008Inventors: Lawrence A. Smith, Abraham P. Gelbein
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Publication number: 20070286794Abstract: Process for the recovery of sulfuric acid comprising: (a) contacting a stream containing sulfuric acid vapor and/or sulfur trioxide in an absorption stage with a ionic liquid absorbent, (b) withdrawing a gas substantially free of sulfuric acid vapor and/or sulfur trioxide from said absorption stage, (c) withdrawing a stream comprising the ionic liquid absorbent from said absorption stage, in which said ionic liquid absorbent contains sulfuric acid, (d) recovering sulfuric acid from said ionic liquid absorbent by passing the stream of step (c) through a separation stage, (e) withdrawing from the separation stage (d) a stream rich in sulfuric acid, (f) withdrawing from the separating step (d) a ionic liquid absorbent stream in which said ionic liquid absorbent contains sulfuric acid and returning said stream to the absorption step (a).Type: ApplicationFiled: June 4, 2007Publication date: December 13, 2007Inventors: Sven Ivar Hommeltoft, Morten Thellefsen
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Patent number: 7273599Abstract: A method for decoloring sulfuric acid containing organic reatives by which it is possible to obtain a crystalline sulfuric acid having a color index of less that 30 APHA unities, by adding controlled amounts of potassium chlorate and hydrogen peroxide in a controlled environment.Type: GrantFiled: April 21, 2006Date of Patent: September 25, 2007Assignee: Servicios Industriales Penoles S.A. de C.V.Inventors: José Antonio Macias Horta, Mauro Medina Herrera, Saul Aviña Vielma, Jesús Ariel Gonzalez Ramirez
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Patent number: 7232554Abstract: A process for the recovery of arsenic trioxide from acid solutions, particularly the aqueous acid effluent produced by a gas-washing process in the pyrometallurgy of copper sulfide ores is provided. Generally, the process comprises concentrating the acid solution in one or more evaporators in series; crystallizing arsenic contained in the concentrated solution as arsenic trioxide crystals; filtering the crystallized solution to obtain a solid phase comprising impure arsenic trioxide crystals; and purifying the solid phase to obtain a purified crystal product comprising arsenic trioxide. The process produces a commercially salable arsenic trioxide product without producing any solid or liquid residues subject to special handling or treatment regulations.Type: GrantFiled: December 14, 2001Date of Patent: June 19, 2007Assignee: Barrick Gold CorporationInventors: Jose Mendoza Videla, Jorge Balanda Andina, Hector Gallegos Cisternas
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Patent number: 7033565Abstract: A process for the production of sulphuric acid from a sulphur dioxide containing feed gas with concentration of SO2 fluctuating between 0 and 100 mole % SO2 comprising the steps of contacting the feed gas with an aqueous solution comprising 0–50% by weight H2SO4 at a temperature between the freezing point of said aqueous solution and 80° C.; and during the contact of the feed gas with the aqueous solution absorbing at least a part of SO2 in the feed gas in the aqueous solution or desorbing at least a part of SO2 from the aqueous solution, wherein the at least a part of SO2 is desorbed by stripping the aqueous solution with the feed gas and passing at least part of the thus treated feed gas to a sulphuric acid plant.Type: GrantFiled: August 6, 2004Date of Patent: April 25, 2006Assignee: Haldor Topsoe A/SInventors: Kurt Agerbæk Christensen, Peter Schoubye
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Publication number: 20040126311Abstract: A process for the removal of organic impurities from sulfuric acid utilizing either liquid or super critical carbon dioxide is provided. The process comprises providing a solution of sulfuric acid contaminated with at least one organic compound and subjecting the solution to countercurrent extraction with one of supercritical carbon dioxide and liquid carbon dioxide. Processes for removing organic contaminants from a waste stream generated in the manufacture of trinitrotoluene are also provided.Type: ApplicationFiled: December 31, 2002Publication date: July 1, 2004Inventors: Andrew Sanderson, Sharon Dressen
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Patent number: 6740302Abstract: The invention relates to a novel method for producing high-purity sulfuric acid for use in the semiconductor industry. The method comprises the addition of a hydrogen peroxide solution to an engineered oelum in order to reduce the SO2 concentration, evaporation of the SO3 and separation of acid traces. The high-purity SO3 is then enriched with inert gas and the SO3 is absorbed into sulfuric acid.Type: GrantFiled: June 26, 2002Date of Patent: May 25, 2004Assignee: Merck Patent GmbHInventors: Martin Hostalek, Werner Büttner, Rolf Hafner, Chih-Peng Lu, Ching-Jung Kan, Ekkehart Seitz, Ernst Friedel
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Patent number: 6649070Abstract: A technique of utilizing a sulfuric acid/peroxide liquid mixture, for example, its waste liquid material, is to be developed so that the waste liquid can be re-utilized and effectively applied to obviate the problem resulting from disposal. To this end, there is provided a method for utilizing a sulfuric acid/peroxide liquid mixture, for example, its waste liquid, in which peroxide in the sulfuric acid/peroxide liquid mixture is decomposed to render it possible to utilize the liquid mixture as sulfuric acid.Type: GrantFiled: December 1, 1998Date of Patent: November 18, 2003Assignee: Sony CorporationInventor: Yasuhito Inagaki
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Patent number: 6641791Abstract: The invention relates to the preparation of BF3 and H2SO4 of commercial grade from boron trifluoride hydrate effluents containing organic impurities. The process consists essentially in reacting the said effluent with oleum, in recovering the gaseous boron trifluoride thereby liberated and in subjecting the sulphuric acid by-product to treatment with hydrogen peroxide and to purging with air.Type: GrantFiled: December 8, 1998Date of Patent: November 4, 2003Assignee: Elf AtochemInventors: Jean-Paul Chalieux, Christian Pralus
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Patent number: 6627172Abstract: Process for preparing sulphuric acid from gasses containing SO3 and gaseous nitrosylsulphuric acid (NO+HSO4− or HO3SONO) by contact with 94% to 98% sulphuric acid, wherein the gases flow through at least one cooler and are cooled down to 160° C. to 130° C. to condense out nitrosylsulphuric acid before being brought into contact with the sulphuric acid.Type: GrantFiled: June 14, 1999Date of Patent: September 30, 2003Assignee: Metallgesellschaft AktiengesellschaftInventors: Hartmut Wagner, Roland Fach
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Publication number: 20030079981Abstract: A distilling apparatus and method use a two step distillation and purification process for processing a waste liquid, such as an impure sulfuric acid solution, to form a highly concentrated sulfuric acid solution. First, the waste liquid is stored in a concentrating column, where it is heated. A condenser, which uses the waste liquid as a cooling medium, condenses the vapor generated by the heater. The condensed vapor is passed through a filter, which separates impurities out of the waste liquid, prior to feeding the waste liquid back into the concentrating column. Water is then removed from the waste liquid via a distilling process. The resulting concentrated liquid is then fed to a purifying column, where it is again heated, to remove residue, and condensed, resulting in a highly pure waste liquid.Type: ApplicationFiled: November 22, 2002Publication date: May 1, 2003Applicant: FUJITSU LIMITEDInventors: Hiroshi Osuda, Toru Matoba, Daisuke Adachi, Masataka Fukuizumi
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Patent number: 6548038Abstract: A process is provided for increasing the concentration of sulfuric acid in a waste solution of sulfuric acid previously used to produce titanium dioxide. The waste solution of sulfuric acid is fed into a first heat exchanger/evaporator stage that operates at a sulfuric acid concentration of less than 30%. A portion of the solution discharged from the first heat exchanger/evaporator is fed into a heat exchanger/evaporator that uses waste heat and operates at a sulfuric acid concentration that is greater than 40%, while the remainder of the solution discharged from the first heat exchanger/evaporator and the solution discharged from the heat exchanger/evaporator using waste heat is fed into a second heat exchanger/evaporator that operates at a sulfuric acid concentration that is greater than 50%.Type: GrantFiled: January 29, 2001Date of Patent: April 15, 2003Assignee: Tioxide Group Services LimitedInventor: James Henry Bush
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Patent number: 6495024Abstract: The object of this invention is a method by which arsenic is removed from sulfuric acid solution, in which the sulfuric add concentration is at least 300 g/l, at a temperature of 50-105° C. by reducing the arsenic in the solution with the aid of sulfur dioxide. The arsenic trioxide produced is crystallized from the sulfuric acid solution by cooling. The method is particularly suitable for use in connection with the electrolytic refining of metals, as in copper refining.Type: GrantFiled: November 28, 2000Date of Patent: December 17, 2002Assignee: Cutokumpo OYJInventors: Leo Lindroos, Henri Virtanen
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Publication number: 20020031469Abstract: Process and apparatus for regenerating spent acid liquor includes a primary roasting furnace for evaporating a substantial portion of the liquid from the spent acid to produce acid vapors and partially roasted metal salts. The partially roasted metal salts are transferred to a secondary roasting chamber where the acids adhering to the surface of the metal salts is vaporized and the metal salts are oxidized. The acid vapors from the primary roasting furnace are then transferred to an absorption column to regenerate the acid. The primary roasting furnace is operated at a different temperature from the secondary roasting chamber and has different retention times for the metal salts. The secondary roasting chamber includes a raking device to mix and convey the metal salts during the secondary roasting step to produce a uniformly roasted metal oxide.Type: ApplicationFiled: January 8, 2001Publication date: March 14, 2002Inventor: Albert Lebl
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Patent number: 6337061Abstract: For the purpose of efficiently and easily regenerating a sulfuric acid solution having a high concentration and a low impurity content from a metal sulfate-containing waste sulfuric acid solution and waste liquor formed during acid cleaning which are discharged from titanium (IV) oxide-production process carried out according to the sulfuric acid method, titanium present in the metal sulfate-containing waste sulfuric acid solution is removed through a solvent-extraction treatment and then the solution obtained after the solvent-extraction is subjected to a diffusive dialysis treatment.Type: GrantFiled: March 28, 1995Date of Patent: January 8, 2002Assignee: Nittetsu Mining Co., Ltd.Inventors: Nobuyoshi Iyatomi, Yasuie Mikami
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Patent number: 6332949Abstract: A process for concentrating spent sulphuric acids particularly sulphuric acids which arise during the nitration of hydrocarbons with nitric acid in the presence of sulphuric acid, wherein single- or multi-stage concentration is effected under vacuum.Type: GrantFiled: March 30, 1999Date of Patent: December 25, 2001Assignee: Bayer AktiengesellschaftInventors: Heiko Beckhaus, Jürgen Münnig, Wolfgang Lorenz, Karl Schumacher
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Patent number: 6315975Abstract: Fumed silica is used to suspend iron sulfates in concentrated sulfuric acid. The suspension system substantially reduces iron sulfate deposits in steel containment vessels.Type: GrantFiled: September 10, 1999Date of Patent: November 13, 2001Assignee: Rhodia Inc.Inventor: Donald Edward Lindblad
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Patent number: 6238639Abstract: Nitrosylsulphuric acid is mixed in a mixing reactor with sulphuric acid saturated with SO2. The acid mixture is led into a saturating reactor into the bottom region of which water and an SO2-containing gas are introduced. The gas partially serves as stripping gas inside the saturating reactor. SO2-saturated, Nox-free sulphuric acid with 5 to 60 wt % H2SO4 is removed from the bottom region of the saturating reactor and part thereof is mixed with nitrosylsulphuric acid in the mixing reactor.Type: GrantFiled: May 14, 1999Date of Patent: May 29, 2001Assignee: Metallgesellschaft AktiengesellschaftInventors: Georg Schmidt, Egon Winkler, Hartmut Wagner, Ronald Apel, Roland Fach, Dieter Knoblich, Peter-Bernhard Stougie
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Patent number: 6214304Abstract: A method of removing mercury from a mercury-containing flue gas, especially flue gas from a refuse incinerator, is provided. The mercury-containing flue gas may also contain dust, further heavy metals, and further gaseous noxious gas components. The mercury, using an alkali sulfide solution, especially sodium sulfide solution, and in particular sodium tetrasulfide solution, is converted to mercury sulfide and the mercury sulfide is precipitated out via a dust separator. The alkali sulfide solution is introduced into the flue gas accompanied by the simultaneous addition of heat.Type: GrantFiled: December 15, 1999Date of Patent: April 10, 2001Assignee: L & C Steinmüller GmbHInventors: Jürgen Rosenthal, Wolfgang Schüttenheim, Marton Klein, Rüdiger Heidrich, Ulrich Nikolai, Uwe Soldner
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Patent number: 6159382Abstract: A process for purifying a sulfuric acid solution such as by cooling a sulfuric acid solution to at or near its freezing point to form a slurry of a solid phase and a liquid phase. The slurry has an acid-rich region and an acid-poor region. The acid-rich region is separated from the acid-poor region on the basis of density.Type: GrantFiled: October 7, 1998Date of Patent: December 12, 2000Assignee: Waterworks International Inc.Inventors: Lawrence D. Conant, Arie Keus
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Patent number: 6156288Abstract: A process is provided for the purification of sulfuric acid contaminated with impurities, such as nitric acid, nitrosylsulfuric acid, dinitrotoluenes and mononitrotoluenes, wherein this contaminated sulfuric acid was obtained from the production of nitrated toluene using toluene and nitric acid. The contaminated sulfuric acid is preheated to a temperature in the range of 50 to 180.degree. C. in a heat exchanger. The heated, contaminated sulfuric acid is freed from steam-volatile impurities, such as dinitrotoluenes and mononitrotoluenes, and the nitrogen-containing compounds within the sulfuric acid are decomposed by counter currently contacting the contaminated sulfuric acid with steam and vapors from a downstream concentration step in a steam stripper, which is operated at a pressure ranging from 300 to 1,000 mbars. The steam-stripped sulfuric acid is fed into a first concentration stage, which is operated at the same pressure used in the steam stripper.Type: GrantFiled: December 4, 1998Date of Patent: December 5, 2000Assignee: Bayer AktiengesellschaftInventors: Heiko Beckhaus, Jurgen Munnig, Dieter Grenner