Forming Insoluble Substance In Liquid Patents (Class 423/34)
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Patent number: 5234669Abstract: Methods are disclosed for treating smelter flue dust and other smelter by-products so as to recover non-ferrous metals therefrom and convert arsenic and sulfur in the flue dust into non-leachable compounds. The methods allow the flue dust and other smelter by-products such as smelter sludges to be disposed of in a natural environment without subsequent leaching of heavy metals, sulfur, and arsenic. The smelter by-products are mixed with hydrated lie, formed into agglomerates, and roasted at an optimal temperature of about 650.degree. C. to form oxidized arsenic and sulfur which react with the lime in the agglomerates to form non-leachable compounds. The roasted agglomerates are contacted with a basic lixiviant comprising dissolved ammonia and an ammonium salt to dissolve non-ferrous metals such as copper from the roasted agglomerates. Used lixiviant can be boiled to precipitate the non-ferrous metals dissolved therein and vaporize the ammonia, thereby regenerating the lixiviant.Type: GrantFiled: August 8, 1991Date of Patent: August 10, 1993Assignee: Idaho Research Foundation, Inc.Inventor: Robert W. Bartlett
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Patent number: 5207996Abstract: Improved methods of heap leaching of copper ore with aqueous sulfuric acid solutions comprising a fluoroaliphatic surfactant are disclosed. The fluoroaliphatic surfactant increases the amount of copper values leached and recovered.Type: GrantFiled: October 10, 1991Date of Patent: May 4, 1993Assignee: Minnesota Mining and Manufacturing CompanyInventors: Michael J. Sierakowski, Frank A. Lee
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Patent number: 5139752Abstract: From an ore containing gold and silver, the gold and silver are extracted by a method which comprises pulverizing the ore and bringing the pulverized ore into contact with an elemental halogen, a halogenated salt, and an organic solvent thereby converting the gold and silver into polyhalogeno anionic complexes and consequently dissolving them in the organic solvent.Type: GrantFiled: August 1, 1991Date of Patent: August 18, 1992Assignees: Agency of Industrial Science and Technology, Ministry of International Trade and IndustryInventors: Yukimichi Nakao, Kyoji Kaeriyama
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Patent number: 5137700Abstract: Aqueous iodine-iodide etching solutions are employed in the recovery of precious metals. Elemental iodine is precipitated from spent etching solutions and used to supply both the iodine and iodide of new etching solutions. Prior to extraction of the elemental iodine, used solutions, if not substantially contaminated, may be oxidized and recycled for further precious metal recovery. Aqueous etching solutions of hydriodic acid and iodine, or of ammonium iodide and iodine may be employed. Etching in such solutions, as well as in solutions of iodine and an alkali metal iodide, such as potassium iodide, may be accelerated by the use of small amounts of hydrogen peroxide (or equivalents) during etching.Type: GrantFiled: April 24, 1989Date of Patent: August 11, 1992Assignee: Nelson H. ShapiroInventor: Hilbert Sloan
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Patent number: 5133948Abstract: Bismuth impurity is removed from copper electrolyte by contacting the electrolyte with an effective amount of finely divided lead oxide.Type: GrantFiled: July 11, 1991Date of Patent: July 28, 1992Assignee: ASARCO IncorporatedInventors: Michael G. King, Jonathan S. Jackson, Wing H. Heung
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Patent number: 5126116Abstract: The invention provides a method of forming copper arsenate. Copper and arsenic are leached into a treatment solution maintained at a pH level of about 2 to 5 in the presence of at least one impurity. An oxidant is added to the treatment solution to oxidize the copper and arsenic. A copper arsenate compound is precipitated from the solution as copper arsenate. Preferably, the copper arsenate is then releached in a purification solution. The molar ratio of copper to arsenic is adjusted to a level of at least 2. The pH of the purification solution is then increased to precipitate copper arsenate having a decreased concentration of said at least one impurity. Impure copper arsenate may be suspended and reacted in a recrystallization solution preferably having cupric ion. The pH of recrystallization solution is adjusted to a valve between about 1 and 4.5.Type: GrantFiled: June 17, 1991Date of Patent: June 30, 1992Assignee: Inco LimitedInventors: Eberhard Krause, Vladimir J. Zatka, Steven W. Laundry
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Patent number: 5114687Abstract: Gold and silver are extracted from their elemental state or from complex ores and alloys by leaching them with a solution containing ammonia, ammonium salts and one or more oxidants. The process is particularly effective for refractory gold ores including sulfide and carbonaceous ores.Type: GrantFiled: December 14, 1990Date of Patent: May 19, 1992Assignee: South Dakota School of Mines & TechnologyInventors: Kenneth N. Han, Xinghui Meng
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Patent number: 5102640Abstract: Dipicolylamine (DPA) is chemically bound to the surface of a silicate, forming a solid phase particle without substantially decreasing the affinity constant of the DPA for certain ions. Then, the solid phase particle is contacted with the solution, thereby binding an ion to the particle. Subsequently the ion can be stripped from the ligand by treatment with a complexing agent or acid.Type: GrantFiled: June 29, 1990Date of Patent: April 7, 1992Inventor: Carl W. Schlapfer
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Patent number: 5085836Abstract: A method to reduce dissolved silver present in spent, waste, photographic processing fluids containing thiosulfate, is described. This process involves adjusting the pH to a low level prior to the addition of finely ground steel to the solution. With the pH at the low level, e.g. 2.5, the reaction of dissolved silver to precipitated silver, is facilitated. However, the pH must then be raised or neutralized, e.g. 7-8.5, in order to insure that the dissolved silver is essentially all precipitated. This material can now be safely shipped without treatment as a hazardous material and, after filtering the solids therefrom, can be safely disposed.Type: GrantFiled: December 3, 1990Date of Patent: February 4, 1992Assignee: E. I. du Pont de Nemours and CompanyInventor: Barbara T. Booker
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Patent number: 5000928Abstract: Ultra-pure silver nitrate is prepared from crude silver by a process comprising the steps of dissolving the crude silver in nitric acid to form a crude silver nitrate solution; adding an alkaline agent, such as sodium hydroxide, to the crude silver nitrate solution to precipitate metallic contaminants and form a partially purified silver nitrate solution; adding a selective reducing agent, such as sodium formate, to the partially purified silver nitrate solution, to reduce silver nitrate to metallic silver and thereby precipitate silver powder while leaving metallic contaminants in solution; dissolving the silver powder in nitric acid to form a highly purified silver nitrate solution; and crystallizing ultra-pure silver nitrate from the highly purified silver nitrate solution.Type: GrantFiled: March 17, 1986Date of Patent: March 19, 1991Assignee: Eastman Kodak CompanyInventor: Weimar W. White
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Patent number: 4980071Abstract: Heavy metals can be precipitated from waste water or aqueous reaction solutions containing inorganic and/or organic complexing agents with substituted thiorureas of the general formula R.sub.1 R.sub.2 N-CS-NH-COR.sub.3. N,N-dialkyl-N'-benzoyl thioureas are used with preference, whereby methyl, ethyl, n-propyl or isobutyl groups are used as alkyl substituents.Type: GrantFiled: November 14, 1989Date of Patent: December 25, 1990Assignee: Degussa AktiengesellschaftInventors: Michael Schuster, Karl-Heinz Koenig, Hermann Lotter, Karlheinz Drauz
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Patent number: 4956154Abstract: Aqueous effluent solutions containing metal cations may be treated with an extractant comprising an organophosphinic acid, a di-2-ethylhexyl phosphoric acid and/or an aliphatic amine to selectively separate chromium, nickel, cobalt, copper and lead cations from the aqueous solution. Typical extraction techniques include liquid-liquid extraction employing either mixer settlers or columns, liquid membrane extraction and selective supported membrane extraction.Type: GrantFiled: March 9, 1988Date of Patent: September 11, 1990Assignee: UNC ReclamationInventors: Alex Magdics, Donald B. Stain
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Patent number: 4925485Abstract: The present invention involves the isolation or leaching of noble metals from materials containing noble metals, e.g. ores, by treating the noble metal- containing materials with a cyclic thiourea derivative under acid pH conditions. Removal is effected by adsorption onto charcoal or by an ion exchanger, for example. Preferred cyclic thioureas are N,N'-ethylenethiourea and N,N'-propylenethiourea and the acid pH conditions may be achieved by sulfuric acid or hydrochloric acid solutions containing 0.01 to 2.0% by weight of the cyclic thiourea.Type: GrantFiled: December 26, 1984Date of Patent: May 15, 1990Assignee: SKW Trostberg AktiengesellschaftInventor: Reinhold Schulze
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Patent number: 4915730Abstract: A process and apparatus for the recovery of metals such as silver from phosphate flue dust. The process includes the steps of blending chloride salt and the flue dust to produce a blended material, roasting the blended material in an oxygen bearing atmosphere to oxidize carbon in the blended material producing a gas and to react chloride salt with the metal in the blended material producing a water soluble metallic salt, dissolving the metallic salt in water to produce a solution, filtering the solution to remove solids, and precipitating metals from the filtered solution with the precipitate ready for conventional smelting. The preferred embodiment of the apparatus includes a flue dust hopper and mill and a salt hopper and mill for feeding the dust and salt to a radiant tube dryer and a radiant tube asher for blending and roasting the materials, and a spray chamber at the outlet of the asher for separating solids and gases, where certain of the solids go into solution.Type: GrantFiled: July 13, 1989Date of Patent: April 10, 1990Inventors: Allan Elias, Hans W. Rasmussen
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Patent number: 4897315Abstract: A protective coating system for superalloys is described. The coating is an yttrium enriched aluminide, and can be formed by aluminizing an MCrAlY coated superalloy, wherein during the aluminizing process, aluminum diffuses completely through the MCrAlY coating and into the substrate. The coating system exhibits desirable oxidation resistance and resistance to thermal fatigue cracking.Type: GrantFiled: September 3, 1986Date of Patent: January 30, 1990Assignee: United Technologies CorporationInventor: Dinesh K. Gupta
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Patent number: 4885098Abstract: An elastic bar member is coupled to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a slurry having particulate material contained therein such as a mineral ore reject from which metal has been extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal quadrature pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the agglomeration or coagulation of the particles in the material and enhances the settling operation to make for more complete separation of the particles from the liquid.Type: GrantFiled: October 21, 1988Date of Patent: December 5, 1989Inventor: Albert G. Bodine
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Patent number: 4883532Abstract: An elastic bar member is clamped to an orbiting mass oscillator and the entire assembly is suspended from a cable or the like such that the bar member has freedom of lateral motion and is nakedly immersed in a leachant having a material contained therein such as a mineral ore from which metal is to be extracted. The rotor of the orbiting mass oscillator is driven at a speed such as to generate cycloidal sonic energy in the bar preferably at a frequency such as to set up resonant standing wave vibration of the bar in a cycloidal nutating pattern. The cycloidal vibrational energy tends to set the surrounding fluid material into a whirling rotation or rotary traveling wave which facilitates the mixing of the ore and leachant and enhances the leaching operation to make for more complete separation of the mineral from the ore.Type: GrantFiled: July 22, 1988Date of Patent: November 28, 1989Inventor: Albert G. Bodine
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Patent number: 4878945Abstract: This invention is directed to an improved process for leach treating gold and silver bearing pyritic and arsenopyritic concentrates and ores. More particularly, the improved process avoids the necessity of adding recycled neutralized solution to the leach solution, thereby alleviating difficulties in maintaining acid levels in the leach solution, and provides for bleeding solutions containing dissolved arsenic, iron and sulphate from the process without the loss oxidized nitrogen species. The process can be carried out in one or more tubular reactors. The process for recovering valuable metals from pyritic and arsenopyritic concentrates and ores involves decomposing the arsenopyrite or pyrite concentrates and ores in acidic solution in a common volume space which contains a gas phase and a liquid slurry (which comprises a liquid phase and a solid phase) through the action of higher valence oxidized nitrogen species in which the nitrogen has a valence of at least plus 3.Type: GrantFiled: September 18, 1987Date of Patent: November 7, 1989Inventors: Rein Raudsepp, Morris J. Beattie
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Patent number: 4859293Abstract: Disclosed are processes and an apparatus for refining gold. One of the processes comprises dissolving unrefined gold by use of iodine and/or an iodide compound to form a solution containing an iodide compound of gold, removing insoluble substances in the solution, reducing the ions containing the gold by use of an alkali to precipitate the gold of high purity. In this process, the iodine may be obtained by electrolyzing the iodide compound. The other process and the apparatus further comprise circulating the solution having been separated from the precipitated gold for reuse, and the alkali simultaneously produced by the above electrolysis is economically employed therein.Type: GrantFiled: July 15, 1987Date of Patent: August 22, 1989Assignee: Tanaka Kikinzoku Kogyo K.K.Inventors: Mamoru Hirako, Nobuyasu Ezawa
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Patent number: 4828809Abstract: Nickel is separated from copper contained in predominantly nickel- and copper-bearing sulphidic matte and alloys by chlorine leaching in an autoclave at over-atmospheric pressure. The leaching is conducted in an acidic solution at a redox potential range which favors the dissolution of nickel over copper. The obtained leach solution is purified in a cementation step carried out at atmospheric or over-atmospheric pressure by adding more sulphidic matte or alloy particles. The separated purified solution is treated for nickel recovery. Any cobalt present in the sulphidic matte or alloy reports with the nickel. Copper is recovered from the separated residue, which will also retain precious metals, if present.Type: GrantFiled: April 24, 1986Date of Patent: May 9, 1989Assignee: Falconbridge, LimitedInventors: Thomas Thomassen, Carl O. Kostol, Hans Zachariansen
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Patent number: 4816235Abstract: A method for obtaining silver and manganese metal from a silver-manganese ore includes the step of leaching the ore with acidified thiourea. More specifically, the method includes the step of leaching the ore with an acidic thiourea solution to form a leach liquor containing compounds of silver and manganese and an insoluble ore residue. The leach liquor is contacted with a quantity of activated carbon to adsorb the silver thiourea complexes on the carbon and to form an extract solution containing the manganese compounds. Next, the carbon which contains adsorbed silver thiourea complexes is contacted with an eluant to desorb the silver complexes from the carbon. The silver metal is recovered from the silver complexes obtained from desorbing the carbon. The manganese metal is recovered from the extract solution. The ore subjected to acidic thiourea leaching is selected from the group consisting of in situ ore, mined ore, comminuted ore, and ore concentrate.Type: GrantFiled: February 24, 1987Date of Patent: March 28, 1989Inventor: Batric Pesic
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Patent number: 4802993Abstract: A method of treating liquid wastes containing heavy metal chelate compounds which comprises reducing the pH of liquid wastes containing the heavey metal chelate compounds to 4 or less, adding iron polysulfate or at least one heavy metal ion selected from a source of Fe.sup.++, Fe.sup.+++, Cu.sup.++, Ni.sup.++ and Zn.sup.++ other than the iron polysulfate to form an iron chelate compound, then forming a solution containing Ca.sup.++ ions at pH 9 or more, and flocculating to precipitate thereby separating the resulting heavy metal hydroxides. The method gives a high heavy metal and COD removal rates, as well as showing good separability for flocks upon flocculating treatment.Type: GrantFiled: June 22, 1987Date of Patent: February 7, 1989Assignee: Hitachi, Ltd.Inventor: Seiji Katoh
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Patent number: 4786323Abstract: A process for the hydrometallurgical recovery of gold and silver by direct oxidizing sulphuric acid-digestion of arsenopyrite-concentrates (FeAsS.sub.2) containing carbonaceous materials with a silicate gangue, and/or a silicate and pyrite gangue whereby arsenic and iron are fully solubilized and the noble metals are quantitatively enriched in the silicate-residue. The concentrate is subjected to mechano-chemical stress to produce structural deformations before being digested in the presence of oxygen. After decarbonization of the residue, gold and silver can be recovered by cyanide leaching without losses due to adsorption. A bulk process for preparing gold and silver rich concentrates is also disclosed.Type: GrantFiled: September 23, 1986Date of Patent: November 22, 1988Inventors: Eberhard Gock, Elias Asiam
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Patent number: 4778519Abstract: A method is provided for recovering gold and silver from precious metal bearing materials including ores, leaching residues, flue dust, electronic scrap, jewelry scrap, etc. In the method, the gold and silver are extracted from the precious metal bearing materials with a thiourea solution to form a thiourea leach, and the thiourea leach is contacted with carbon to adsorb the gold and silver and provide loaded carbon. The method is characterized by the step of contacting an alkaline solution of thiousulfate ion with the loaded carbon thereby desorbing the precious metals form the carbon. In one modification of the method, an additional step includes adding a salt to the aqueous thiousulfate solution. When needed, the method includes the step of protecting the thiousulfate ion from oxidizing agents. This is done by adding a reducing agent such as sodium sulfite to the thiousulfate solution.Type: GrantFiled: April 7, 1987Date of Patent: October 18, 1988Inventor: Batric Pesic
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Patent number: 4738718Abstract: A gold recovery pretreatment process is disclosed in which the gold content is more completely extracted from refractory sulfidic ores which contain large quantities of metal carbonates such as dolomite than occurs in traditional gold extraction methods. The process includes treating the ore in an autoclave at elevated temperature and oxygen overpressure conditions in the presence of soda ash or other alkaline materials. The autoclaving of the slurried ore is performed for a sufficient amount of time to oxidize the sulfidic compounds in the ore. The oxidized ore is then more amenable to subsequent conventional gold extraction techniques.Type: GrantFiled: October 28, 1985Date of Patent: April 19, 1988Assignee: Freeport Minerals CompanyInventors: Nandkumar Bakshani, Peter H. Yu
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Patent number: 4731113Abstract: A process for the recovery of precious metals from ore containing the same is disclosed. The process includes the formation of a lixiviant solution including a thiourea compound, urea and an alkali lignin sulfonate. The ore is then exposed to this lixiviant solution to extract the previous metals therefrom, and the dissolved previous metals are then recovered from the solution.Type: GrantFiled: August 13, 1986Date of Patent: March 15, 1988Inventor: Roger H. Little
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Patent number: 4671945Abstract: This is a method for the complete leaching of the valuable metals in a metal sulphide material which contains copper, zinc, lead, silver and iron by the use of a solution which essentially contains cupric chloride/sulphates. After the valuable metals have been recovered, the solution is regenerated whereby ferrous chloride and cuprous chloride/sulphate is oxidized to a ferric hydroxide solid and a cupric chloride solution respectively. The regenerated solution is split into two part-solutions and returned to the process.One part-solution goes to a metathesis stage where the fresh metal sulphide material is added in large excess with respect to the part-solutions's content of copper. The result is that only the valuable metals like zinc, lead and silver are leached while copper and iron remain in the residue.The other part-solution goes to a leach stage where the residue from the metathesis stage is added.Type: GrantFiled: October 29, 1985Date of Patent: June 9, 1987Inventors: Thomas Thomassen, Carl O. Kostol
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Patent number: 4668289Abstract: A method for reclaiming gold in metallic form from gold-containing scrap, including gold-containing base metal alloys and articles in which base metals are at least partially covered with a layer of gold. The method includes the steps of exposing the gold-containing scrap under an inert atmosphere to a leaching solution. The leaching solution has dissolved therein an oxidizing agent including metal ions capable of assuming at least two oxidation states, a portion of the metal ions being in the higher of the two oxidation states. The leaching solution also contains a complexing agent including halide ions in aqueous solution. By so exposing the gold-containing scrap to the leaching solution, base metal contained therein is dissolved to leave a solid metallic residue enriched in gold. The solid metallic residue then is collected mechanically.Type: GrantFiled: November 22, 1985Date of Patent: May 26, 1987Assignee: Wisconsin Alumni Research FoundationInventors: Stanley H. Langer, Abel Saud, George McDonald, James A. Koutsky
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Patent number: 4647307Abstract: A process for the hydrometallurgical recovery of precious metal from an ore or concentrate containing at least some arsenopyrite or pyrite.Type: GrantFiled: November 14, 1985Date of Patent: March 3, 1987Inventors: Rein Raudsepp, Ernest Peters, Morris J. V. Beattie
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Patent number: 4645535Abstract: A process for the recovery of precious metals from ore containing the same is disclosed. The process includes the formation of a lixiviant solution including a thiourea compound, urea and potassium lignin sulfonate. The ore is then exposed to this lixiviant solution to extract the precious metals therefrom, and the dissolved precious metals are then recovered from the solution.Type: GrantFiled: August 15, 1985Date of Patent: February 24, 1987Inventor: Roger H. Little
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Patent number: 4629570Abstract: A process is described for removing dissolved iron from an aqueous liquid containing iron in the form of a soluble complex with alkylenepolyamine polyacetic acids or salts thereof. The process comprises the steps of (a) adjusting the pH of said aqueous liquid to at least about 12.5, (b) adding sufficient quantities of a soluble calcium salt to facilitate the growth of insoluble iron hydroxide particles, and (c) separating the resulting insoluble mass containing iron hydroxide from the liquid effluent.Type: GrantFiled: July 18, 1985Date of Patent: December 16, 1986Assignee: Dowell Schlumberger IncorporatedInventor: Weldon C. Kennedy, Jr.
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Patent number: 4615731Abstract: A hydrometallurgical process is provided for separating heavy metal nuisance elements such as As, Sb, Bi, Sn and Pb from precious metals and/or selenium. The process can be used as a step in an overall hydrometallurgical process for treating refinery residues such as anode slimes for the separation and recovery of valuable metal values.Type: GrantFiled: February 9, 1985Date of Patent: October 7, 1986Assignee: Inco LimitedInventors: John A. Thomas, Norman C. Nissen, Malcolm C. E. Bell, Alexander Illis
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Patent number: 4612093Abstract: A novel gold purification method is provided which comprises electrolyzing gold into a novel pregnant electrolyte, segregating the dissolved gold ions from the cathode by a semipermeable barrier, separating insoluble impurities from the gold-containing liquidus, and then selectively reducing the gold to metallic form from the liquidus by a selective chemical reducing agent. The electrolyte is impregnated with a catalyst for leveling the overvoltage of gold and preferably contains a peroxide or a nascent oxygen source. A unitary apparatus for the method is provided.Type: GrantFiled: May 31, 1985Date of Patent: September 16, 1986Assignee: Shor International CorporationInventor: Peter S. Shor
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Patent number: 4612125Abstract: A method for removing heavy metals from wastewater streams removes such heavy metal by treating heavy metal-containing wastewater with a water soluble tri-thio carbonate, particularly an alkali metal tri-thio carbonate, such as sodium tri-thio carbonate (Na.sub.2 CS.sub.3) to precipitate heavy metals therefrom.Type: GrantFiled: June 20, 1985Date of Patent: September 16, 1986Assignee: CX/Oxytech, Inc.Inventor: Geraldine S. Elfline
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Patent number: 4605537Abstract: Residual hypochlorite contained in chlorinated slurries of either carbonaceous gold-containing ores or mixtures of carbonaceous and oxide gold-containing ores are reduced by reaction with sulfide ion-providing chemical compounds preferably sodium hydrosulfide, sodium sulfide or hydrogen sulfide. The hypochlorite "kill" step enables subsequent cyanide leach operations to be conducted more efficiently.Type: GrantFiled: September 17, 1984Date of Patent: August 12, 1986Assignee: Freeport Minerals CompanyInventor: Freddie J. Touro
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Patent number: 4585561Abstract: A flotation process for the continuous recovery of silver or silver compounds from solutions or dispersions is described, wherein finely divided, inert gas bubbles are injected into the dispersions of silver and silver compounds in the presence of protein and the pH of the medium is maintained at the isoelectric point of the protein. Addition of a surface active agent accelerates the process. The desilverized effluent has a silver content of less than 1 mg of Ag/l. The quantity of flotate (12) is less than 2% of the quantity of effluent (5) put into the process.Type: GrantFiled: April 8, 1985Date of Patent: April 29, 1986Assignee: Agfa-Gevaert AktiengesellschaftInventors: Marko Zlokarnik, Georg Schindler, Gunther Koepke, Werner Stracke
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Patent number: 4579589Abstract: A process for separating precious metals from a roaster calcine leach residue from a process wherein copper or zinc sulfides are roasted to produce a copper or zinc calcine; the calcine is leached with an aqueous sulfuric acid leaching solution to produce a copper or zinc-containing leaching solution and a roaster calcine leach residue and the copper or zinc-containing leaching solution is separated from the roaster calcine leach residue wherein the process comprises:(a) intimately contacting the roaster calcine leach residue with an aqueous sulfuric acid leach solution containing from about 5 to about 200 grams per liter of sulfuric acid to produce a slurry of leach solution and roaster calcine leach residue and to dissolve precious metal from roaster calcine leach residue;(b) adding copper or zinc sulfide solids to the mixture of leach solution and said roaster calcine each residue;(c) agitating the copper or zinc sulfide solids in intimate contact with the mixture of leach solution and roaster calcine leacType: GrantFiled: November 29, 1984Date of Patent: April 1, 1986Assignee: Atlantic Richfield CompanyInventors: William A. Yuill, Barbara A. Krebs, Gretchen L. Graef
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Patent number: 4544541Abstract: A process is provided for removing hexavalent selenium from an acidic sulfate solution containing at least one metal ion from the group consisting of nickel, cobalt and copper at ambient pressure and at a temperature not exceeding the boiling point of the solution. The solution is treated with an agent from the group consisting of a compound which will produce nascent hydrogen in the solution and finely divided metal from the group consisting of nickel, cobalt and copper resulting from in situ precipitation of the metal in the acid sulfate solution. Thus, following treatment with the compound, the hexavalent selenium is reduced to a form separable from the solution by solid-liquid separation.Type: GrantFiled: June 14, 1984Date of Patent: October 1, 1985Assignee: AMAX Inc.Inventors: Eddie C. Chou, Ben W. Wiegers, Dale K. Huggins, Edward I. Wiewiorowski
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Patent number: 4544460Abstract: Cuprous chloride, which is contained in a reduced leach solution or pregnant liquor, can be recovered as a complex salt of alkali metal chloride, such as potassium chloride, or alkaline earth metal chloride or ammonium chloride. The salts are produced by oxidation of a copper ore, such as chalcopyrite, with ferric chloride and cupric chloride, and after removal of insolubles, by adding sufficient metallic copper to the solution to reduce cupric ions to cuprous ions so as to provide a solution containing 1.5 to 2.5 molal potassium chloride, or other metal or ammonium chloride, and cooling the resultant saturated solution to precipitate the potassium chloride-cuprous chloride complex salts and recovering the complex salts. Also provided as a method for recovery of pure copper metal by electrolysis of solutions derived from the complex salts wherein the impurities are diverted to an anode loop which is separated from the cathode loop by a diaphragm.Type: GrantFiled: June 9, 1981Date of Patent: October 1, 1985Assignee: Duval CorporationInventor: Leonard R. Ochs
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Patent number: 4500498Abstract: Anhydrous zinc chloride is produced from an aqueous feed solution containing zinc chloride from an aqueous feed solution containing zinc chloride. The zinc chloride is extracted onto an organic extractant known to the art such as tributyl phosphate, primary, secondary or tertiary amines, and quaternary amine salts. The loaded extractant is then stripped with aqueous stripping solution containing ammonium chloride and ammonium hydroxide. The zinc ammine chloride formed in this aqueous stripping solution is separated from the stripping solution and can then be heated to form anhydrous zinc chloride and ammonia. This anhydrous zinc chloride is suitable as a feed material to a fused salt electrolysis process for the production of zinc.Type: GrantFiled: January 19, 1984Date of Patent: February 19, 1985Assignee: Cato Research, Inc.Inventors: Paul R. Kruesi, William H. Kruesi
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Patent number: 4445935Abstract: The method of the present invention is directed to the recovery of silver from spent photographic fixer solutions and for providing an effluent essentially silver-free that is suitable for discharge into commercial sewage systems. The present method involves the steps of introducing the spent photographic fixer solution into an alkaline hypochlorite solution. The oxidizing conditions of the alkaline hypochlorite solution are maintained during the addition of the fixer solution so that the silver ion complexing agents of thiosulfate and sulfite ions are effectively destroyed. Hydrazine monohydrate is then added to the oxidizing solution to form a reducing solution to effect the formation of a precipitate of silver which can be readily removed by filtration or decanting. Experimental tests indicate that greater than 99.99% of the original silver in the spent photographic fixer can be efficiently removed by practicing the present method.Type: GrantFiled: December 13, 1982Date of Patent: May 1, 1984Assignee: The United States of America as represented by the United States Department of EnergyInventors: Franz A. Posey, Aloysius A. Palko
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Patent number: 4405569Abstract: This invention relates to environmentally sound hydrometallurgical methods and processes for extraction of cobalt, nickel and silver from complex concentrates. The finely ground minerals are converted during an oxidative caustic leach at elevated pressures and temperatures to insoluble metal hydroxides and are separated from soluble sodium arsenate and sodium sulphate. Cobalt and nickel are extracted from the caustic cake during a two-stage sulphuric acid leach. Solution purification for cobalt and nickel recovery proceeds on the basis that only one waste residue and one liquid effluent are generated which meet strict environmental standards. A small amount of cyanidation residue is generated after silver extraction by cyanidation from the acid leach residue. Metal values extraction reaches +99.0%. Arsenic and sulphur can be recovered in an innovative recycle system as sodium, zinc or copper arsenate chemicals and as anhydrous sodium sulphate.Type: GrantFiled: November 4, 1981Date of Patent: September 20, 1983Assignee: Sulpetro Minerals LimitedInventor: Ulrich Dienstbach
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Patent number: 4401630Abstract: The metal content of nickel-cobalt mixed sulfide slurries is recovered by atmospheric oxidation leaching, thereafter removing dissolved copper by metathesis with further mixed sulfide feed, treating the filtrate after liquid-solids separation with ammonia to selectively precipitate cobalt, separating the cobalt precipitate and working up the resulting filtrate to recover nickel.Type: GrantFiled: August 31, 1981Date of Patent: August 30, 1983Assignee: INCO Ltd.Inventors: Victor A. Ettell, Juraj Babjak
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Patent number: 4381937Abstract: In a process for producing fine cobalt metal powder from scrap material containing brazing compositions, the scrap is digested with hydrochloric acid to form a cobalt chloride solution which the silver is removed by precipitation with a suitable alkali metal halide at a pH of about 7 to result in a cobalt amine chloride solution which is further processed to fine cobalt powder.Type: GrantFiled: September 21, 1981Date of Patent: May 3, 1983Assignee: GTE Products CorporationInventors: Richard G. Gingerich, Clarence D. Vanderpool, Richard A. Scheithauer, Martin B. MacInnis
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Patent number: 4378340Abstract: The present invention relates to a process for removing heavy metals, particularly cadmium, from differing qualities of wet-process phosphoric acids. The invention is based on the concept of removing the heavy metals in sulfide form.Type: GrantFiled: January 10, 1981Date of Patent: March 29, 1983Assignee: Boliden AktiebolagInventor: Hans A. L. Berglund
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Patent number: 4374098Abstract: A method of concentrating silver from anode slime which comprises reacting an intermediate product obtained by treatment of the slime, the intermediate product containing lead in sulfate form and silver in chloride form, with an aqueous solution of an alkali hydroxide or carbonate. The obtained reaction product is then subjected to solid-liquid separation, and the resulting residue is reacted with a nitric acid solution so that the lead therein may be separated into a filtrate, while the silver will remain in the residue.Type: GrantFiled: June 16, 1982Date of Patent: February 15, 1983Assignee: Sumitomo Metal Mining Co., Ltd.Inventors: Toshimasa Iio, Toyokazu Ohkubo
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Patent number: 4364773Abstract: A process is provided by which dissolved metals may be recovered from aqueous waste solutions and converted to a particulate material, which may in turn be used as a filler for products such as asphalt. The process involves effecting reaction in the solution to produce a sludge comprised of metal hydroxides and sulfides, and admixing lime with a concentrate thereof to ultimately produce the filler.Type: GrantFiled: December 23, 1980Date of Patent: December 21, 1982Inventors: Marcel Veronneau, Thomas Marino
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Patent number: 4343781Abstract: Cuprous chloride is produced from the complex salt, 2KCl.CuCl, obtained as a by-product in the copper industry where chalcopyrite is decomposed in the presence of potassium chloride, by a series of steps involving reaction of an aqueous solution of the complex salt of potassium chloride and cuprous chloride with ammonia, separating the resulting solid potassium chloride from a solution containing cuprous chloride and ammonia, removing the ammonia from the solution to cause precipitation of the cuprous chloride and recovering solid cuprous chloride. Ammonia may then be recycled to the solution from which the cuprous chloride is removed and to which additional complex salt is added to repeat the cycle.Type: GrantFiled: June 9, 1981Date of Patent: August 10, 1982Assignee: Pennzoil CompanyInventor: John B. Sardisco
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Patent number: 4331469Abstract: A process for the recovery of silver values from silver-containing material which also contains iron and arsenic includes leaching the material under oxidizing conditions at elevated temperature and pressure in aqueous nitric acid solution to dissolve a substantial amount of silver together with substantial amounts of arsenic, iron and other metals if present. The resultant leach solution is separated from undissolved leach residue and treated with a solution containing chloride ions to selectively precipitate substantially all dissolved silver as silver chloride without significant co-precipitation of other dissolved metals. The silver chloride precipitate is then separated from the remaining solution.Type: GrantFiled: August 19, 1980Date of Patent: May 25, 1982Assignee: Sherritt Gordon Mines LimitedInventor: Wasyl Kunda
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Patent number: 4308239Abstract: Cuprous (Copper (I)) chloride is an intermediate for the production of copper metal concentrates. A method of purifying copper salts and particularly cuprous chloride is disclosed which involves utilizing the solubility of cuprous chloride and other copper salts in a mixture of water and acetonitrile of 2-hydroxycyanoethane or acrylonitrile and the ability of cuprous chloride to precipitate when the organic component of the mixture is distilled off. The electrolysis of cuprous chloride in water containing at least 10 grams per litre of copper (I), acid and between 5% and 50% by volume of a water soluble organic nitrile such as acetonitrile or 2-hydroxycyanoethane is also disclosed.Type: GrantFiled: May 1, 1979Date of Patent: December 29, 1981Assignee: Anumin Pty. Ltd.Inventors: Alan J. Parker, David M. Muir, Eric J. Grimsey, John S. Preston