Forming Insoluble Substance In Liquid Patents (Class 423/140)
  • Patent number: 5800716
    Abstract: A process for the treatment of aqueous acidic liquors containing dissolved aluminum and/or iron compounds to produce an aluminum and/or iron sulfate water-treatment product is characterized by the combination of steps comprising contacting the liquor with a basic material capable of reacting with the dissolved aluminum and/or iron compound to precipitate aluminum and/or iron values, separating the precipitate in the form of a cake or slurry from the remaining liquor, treating the cake or slurry with sulfuric acid to re-dissolve aluminum and/or iron values and to produce a solution of aluminum and/or iron sulfate and separating suspended solid matter from the solution. The liquor may be a waste product from industrial processes or may be a mine effluent and the process avoids the need to dispose of these to waste.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: September 1, 1998
    Assignee: Laporte Industries Limited
    Inventors: Neil Clarke, John Harris Newton
  • Patent number: 5756056
    Abstract: A process for recovering scandium economically with high efficiency by concentration and separation from an oxide ore containing nickel and a small amount of scandium as well as a large amount of iron and/or aluminum comprises the steps of acid leaching the oxide ore under a high-temperature, high-pressure oxidative atmosphere while restraining leaching of the iron and/or aluminum, thereby selectively leaching substantially all nickel and scandium from the ore, recovering the nickel from the resulting leaching solution as a precipitated sulfide while not precipitating the scandium as a sulfide but leaving the total amount thereof in the solution, and then adjusting the pH of the solution with a precipitant to recover the scandium from the solution as a high-concentration scandium hydroxide or carbonate by concentration and separation.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: May 26, 1998
    Assignee: Pacific Metals Co., Ltd.
    Inventors: Akira Kimura, Kosuke Murai, Hiromasa Yakushiji
  • Patent number: 5746994
    Abstract: A method of producing ferrate is disclosed, in which Fe.sup.3+ is oxidized with monoperoxosulfate (HSO.sub.5.sup.-) to form K.sub.2 FeO.sub.4 /K.sub.2 SO.sub.4. The isolation of the potassium ferrate (K.sub.2 FeO.sub.4) product in a sulfate matrix (K.sub.2 SO.sub.4) stabilizes the ferrate against decomposition and inhibits clumping of the solid product by inhibiting moisture adsorption. The method is a safe, simple process for the production of ferrate that is reliable, fast, and inexpensive, and that avoids the use of chlorine or chlorinated products, thus avoiding their harmful side effects. The improved ferrate product of this method is particularly useful for water and wastewater treatment, especially in the treatment of sulfides and hydrazines, and in other applications.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: May 5, 1998
    Assignee: New Mexico State University Technology Transfer Corporation
    Inventor: Michael D. Johnson
  • Patent number: 5728854
    Abstract: A method for separating iron for nickel and/or cadmium contained in a battery waste is composed of a first step in which the spent batteries are crushed and calcined. The calcined pieces are mixed with an acetic acid aqueous solution before acetic acid and water are removed by evaporation or distillation so as to produce a residue containing metallic acetates. Water, the residue and an oxidant are mixed such that Fe.sup.+ and Fe.sup.++ acetates are converted into a basic ferric acetate, Fe(CH.sub.3 COO).sub.2 OH, which is insoluble in water and is recovered by filtration.
    Type: Grant
    Filed: August 6, 1996
    Date of Patent: March 17, 1998
    Assignee: Industrial Technology Research Institute
    Inventors: Ching-Chyi Chen, Fong-Ru Yang
  • Patent number: 5685993
    Abstract: Embodiments of an apparatus and method for ferrite formation and the removal of heavy metal ions by ferrite co-precipitation from an aqueous solution at ambient temperature have been developed. Magnetically susceptible ferrite crystals can be continuously formed from aqueous solution and the heavy metal ion solution can be continuously treated by the ferrite co-precipitation process. The heavy metal ions are incorporated into the lattice points of the spinel ferrite structures. The precipitates of ferrite materials can then be magnetically separated. The main apparatus includes a ferrous sulfate mixing tank with a feeder assembly; a reaction tank or, alternatively, neutralization and oxidation tanks; settling and polishing tanks; and a magnetic separator. The reaction tank or oxidation tank includes an air distributor; a pH controller; and promoter feeding and ferrite product recirculating systems.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: November 11, 1997
    Assignee: Pitts-Mont Environmental Reclamation Corporation
    Inventor: Qi Liu
  • Patent number: 5678242
    Abstract: Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.
    Type: Grant
    Filed: July 7, 1994
    Date of Patent: October 14, 1997
    Assignee: Arch Development Corporation
    Inventors: Earl Philip Horwitz, Ralph Carl Gatrone, Kenneth LaVerne Nash
  • Patent number: 5672280
    Abstract: For the removal of heavy metal contaminants from industrial waste water, a method is proposed for preparing a dense precipitate having superior handling and disposal properties. The method comprises incremental adjustment of the pH to maintain a low saturation ratio and recycling of slurry to provide seed crystals for secondary nucleation.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: September 30, 1997
    Assignees: Her Majesty the Queen in right of Canada, as represented by the Minister of Natural Resources, McGill University
    Inventors: George P. Demopoulos, Janice M. Zinck, Peter D. Kondos
  • Patent number: 5670271
    Abstract: The present invention relates to manganese-containing nickel(II) hydroxide powders, wherein at least 50 mole % of the manganese are present in the trivalent oxidation state, a process for the preparation of such powders and battery electrodes and batteries made therefrom.
    Type: Grant
    Filed: November 1, 1995
    Date of Patent: September 23, 1997
    Assignee: H. C. Starck GmbH & Co., KG
    Inventor: Peter Axmann
  • Patent number: 5665241
    Abstract: A dephosphorizing material containing iron and/or an iron-containing compound, a cementitious material, water, and a mixing agent for accelerating bleeding as the starting material, and having fine pores therein formed by solidifying the starting materials while bleeding not less than 2.0% by weight of the water contained in the starting materials to render the percent water absorption of not less than 10%; and a dephosphorizing method which includes bringing the dephosphorizing material into contact with a phosphorus-containing aqueous solution. This dephosphorizing material can effectively reduce the phosphorus concentration in sewages, rivers, or the like by fixing the phosphorus component on its surface. The dephosphorizing method is so simple that it can be effected merely by bringing the dephosphorizing material into contact with a phosphorus-containing aqueous solution, thus being capable of removing the phosphorus component effectively without necessity for any special controls.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: September 9, 1997
    Assignee: Hazama Corporation
    Inventors: Terunobu Maeda, Atsunori Negishi
  • Patent number: 5665324
    Abstract: Valuable substances are recovered from a spent electroless nickel plating solution containing a water-soluble nickel salt, organic complexing agent, hypophosphite, phosphite, and alkali metal ion by adding oxalic acid to the plating solution for causing a nickel ion to precipitate as nickel oxalate for removal and recovery; optionally adding a sulfide to the plating solution for causing a heavy metal ion to precipitate as a heavy metal sulfide for removal; adding a mineral acid and calcium oxide, calcium hydroxide, calcium carbonate, calcium sulfate, calcium chloride or a calcium salt of organic acid to the plating solution from which the nickel ion has been removed; firing solids of the solution in air for converting the alkali metal ion into an alkali metal salt of mineral acid, converting phosphorus into hydroxyapatite, and pyrolyzing off the organic material; and pouring a solid mixture of the alkali metal salt of mineral acid and hydroxyapatite into water for dissolving the alkali metal salt of mineral a
    Type: Grant
    Filed: July 14, 1995
    Date of Patent: September 9, 1997
    Assignees: Taihei Chemical Industrial Co., Ltd., C. Uyemura & Co., Ltd.
    Inventors: Teruyoshi Izawa, Kazunori Kudo, Yoshihiro Kani, Ken Araki, Tamotsu Kato, Takashi Furui
  • Patent number: 5599514
    Abstract: Process for recovering and re-using cobalt and tungsten from reaction liquors, in which said reaction liquors are treated:a) With an alkali-earth metal hydroxide in order to precipitate cobalt and tungsten, and the resulting precipitate is subsequently treated with a strong mineral acid in order to be able to dissolve the cobalt salt and separate it from H.sub.2 WO.sub.4 precipitate; orb) With an alkali metal hydroxide in order to precipitate and separate Co(OH).sub.2, and the resulting alkaline solution is then treated with an alkali-earth metal compound which is filtered and treated with a strong mineral acid in order to obtain H.sub.2 WO.sub.
    Type: Grant
    Filed: February 6, 1995
    Date of Patent: February 4, 1997
    Assignee: Novaol S.R.L.
    Inventors: Andrea Gardano, Sauro Strologo, Marco Foa'
  • Patent number: 5594929
    Abstract: According to the invention there is now provided a simple method of preparing a powder containing WC and cobalt and/or nickel. APT-powder and a powder of a basic salt of cobalt and/or cobalt are mixed in water or in mixed solvents. The suspension is stirred to react at temperatures ranging from room temperature to the boiling point of the solution whereby a precipitate is formed, which precipitate is filtered off, dried and finally reduced to a metallic powder.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: January 14, 1997
    Assignee: Sandvik AB
    Inventors: Mamoun Muhammed, Sverker Wahlberg, Ingmar Grenthe
  • Patent number: 5562828
    Abstract: Spent acid contaminated with metal salts in a hot solution removed from a metal pickling bath is directed to one side of an anionic membrane to separate acid ions from the metal salt solution by diffusion dialysis through the membrane. Most of the metal salts in the remaining low acidity mother liquor are crystallized by refrigerating the mother liquor. The crystals are dewatered (in a centrifuge, for example) to produce a commercially viable noncorrosive byproduct, and the substantially decontaminated mother liquor is directed to the opposite side of the diffusion membrane, where it receives the acid ions diffusing through the membrane, and is then recycled to the pickling bath. Heat interchange between the hot spent acid solution and the recycled acid lowers the temperature of the spent acid to an optimum value for dialysis while raising the temperature of the recycled acid to close to the bath temperature.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: October 8, 1996
    Inventors: Douglas R. Olsen, Daniel E. Bailey
  • Patent number: 5531903
    Abstract: A process is provided for the removal of fluoride from a metal sulphate solution, such as a zinc sulphate solution, which presents an option for the disposal of waste treatment sludge from the aluminum anodizing industry. The fluoride is removed from metal sulphate solution by mixing the sludge with the solution for a predetermined period of time and then performing a solid/liquid separation.
    Type: Grant
    Filed: March 15, 1995
    Date of Patent: July 2, 1996
    Assignee: Cominco Ltd.
    Inventors: Cashman R. S. M. Hampton, Victor E. Steiner, Daniel A. D. Boateng
  • Patent number: 5518631
    Abstract: A dephosphorizing material disposed so that a material containing iron as a main component and a calcium compound material contact a phosphorus-containing aqueous solution, and provided with a water-permeable material at least around the material containing iron as a main component. A phosphorus component of sewage and river water can be removed easily by simply bringing this dephosphorizing material into contact with such phosphorus-containing aqueous solutions, without employing any special solution control method. This dephosphorizing material is capable of reducing the outflow of iron rust occurring due to the oxidation of iron during a dephosphorization of a phosphorus-containing aqueous solution, and the iron effluent can be eliminated by the action of the calcium compound material. Accordingly, this dephosphorizing material can be applied practically to sewage and river water.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: May 21, 1996
    Assignee: Hazama Corporation
    Inventor: Terunobu Maeda
  • Patent number: 5505857
    Abstract: Metals contained in various wastewaters are selectively recovered as metal precipitates and/or as spinel ferrite and water suitable for discharge into the environment is obtained. High grade magnetic spinel ferrite is recovered from wastewaters having aluminum and arsenic if present in the wastewater, removed from the wastewater. There are three process stages for the treatment of wastewater. In the first process stage which is optional, at least a portion of at least one non-ferrous or non-ferric metal is precipitated from the wastewater by subjecting the wastewater to an oxidizing agent to increase the oxidation-reduction potential of the water, by adjusting the pH of the wastewater to a pH at which the metal precipitates from the water and by adding an organic or inorganic sulfur compound, capable of causing the metal to form a precipitate, to the water in a quantity sufficient to precipitate the metal.
    Type: Grant
    Filed: January 13, 1994
    Date of Patent: April 9, 1996
    Assignees: Buckman Laboratories International, Inc., Board of Regents of the University and Community College System of Nevada on behalf of the University of Nevada
    Inventors: Manoranjan Misra, Mark E. Kravetz, Kang Yang, Thomas E. McNeel
  • Patent number: 5487878
    Abstract: A method for preparing a perpendicularly magnetizable material usable on magnetic recording media comprises the steps of: dissolving at least one member of the group consisting of strontium chloride and strontium nitrate with at least one member of the group consisting of iron chloride and iron nitrate in distilled water; adding citric acid to the resultant solution; controlling the pH of the solution to a range sufficient to completely dissociate the citric acid; heating the resultant solution with stirring to yield a gelatinous precursor; and subjecting the precursor to a temperature sufficiently high to remove the organic constituents thereof, which is characterized by controlling the pH of the solution to gelate the solution without the use of ethylene glycol, and can provide a perpendicularly magnetizable material superior in magnetic and particle properties.
    Type: Grant
    Filed: September 1, 1994
    Date of Patent: January 30, 1996
    Inventors: Young Jei Oh, Jin-Ho Choy, Hyung Jin Jung, Yang Su Han, Seung Wan Song
  • Patent number: 5468281
    Abstract: A process is disclosed for separating cobalt in the form of cobalt (III) hexammine sulphate from an aqueous solution containing cobalt (III) hexammine sulphate and nickel (II) hexammine sulphate comprising adding ammonium sulphate to provide an effective amount of ammonium sulphate, saturating the solution with an effective amount of ammonia at a temperature whereby the triple salt of cobalt (III) hexammine sulphate, nickel (III) hexammine sulphate and ammonium sulphate is precipitated, recovering the precipitated triple salt from the solution, and repulping the triple salt with an effective amount of water or aqueous ammonia solution to selectively leach nickel (II) hexammine sulphate to produce a crystalline cobalt (III) hexammine sulphate with a cobalt: nickel ratio of at least 100:1.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: November 21, 1995
    Assignee: Sherritt Gordon Limited
    Inventor: Derek G. E. Kerfoot
  • Patent number: 5454856
    Abstract: A process for recovering nickel that is in soluble form and in relatively low concentrations, typically up to 2% by weight in a liquor, comprises: (a) precipitating nickel from solution (preferably as a hydroxide or sulphide); (b) adding an inert particulate carrier and a flocculent to the liquor to form flocs comprising nickel precipitate, inert particulate carrier, and flocculent; (c) separating the flocs from the liquor (preferably by gravitational settling or magnetic separation); and (d) separating the nickel precipitate from the flocs (preferably by agitating the flocs). The nickel precipitate and flocs are preferably then passed through a filter to remove the nickel as filter cake. The inert carrier is preferably sand, alumina, magnetite, hematite, ilmenite or calcite. The flocculent is preferably a cationic, non-ionic or anionic flocculent.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: October 3, 1995
    Assignee: Modern Environmental Service Trust
    Inventor: Geoffrey R. Browne
  • Patent number: 5429887
    Abstract: A process for treating an AB.sub.5 Ni--MH battery to recover purified positive and negative electrode components of the battery is disclosed. An AB.sub.5 Ni--MH battery is placed in a mineral acid leach solution to cause the positive and negative electrode components of the battery to separate. The positive and negative electrode components are maintained in the leach solution until the negative electrode component breaks down into its dissolved rare earth metal constituents and metallic solids. The metallic solids remaining from the negative electrode component and the positive electrode components are separated from the mineral acid leach solution and subjected to an elutriation process and thereafter to ball milling to obtain Ni rich powder and Fe. The mineral acid leach solution containing the completely dissolved rare earth metals is subjected to a phosphate precipitation process to recover La and Ce in precipitate, and then subjected to a second precipitation process to recover Ni, Co, Mn and Al.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: July 4, 1995
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventors: Jane W. Lyman, Glenn R. Palmer
  • Patent number: 5407463
    Abstract: Method for recovering cadmium (Cd), nickel (Ni) and iron (Fe) from batteries containing the steps of: (a) reducing the size of the batteries to small pieces and separating the pieces into a coarse fraction and a fine fraction with the coarse fraction further separated into a magnetic and a non-magnetic fraction; (b) leaching out the fraction at approximately 90.degree. C.; (c) removing the Cd; (d) stripping the extractant and separating metallic Cd therefrom; (e) converting Fe-ions into (solid) Fe hydroxide and filtering; (f) recovering Ni from the filtrate.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: April 18, 1995
    Assignee: Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek TNO
    Inventor: Joost van Erkel
  • Patent number: 5399322
    Abstract: Discussed is a process for recovering metals and metal-containing products, such as a nickel sulfate product, from aqueous feed solutions comprising two or more dissolved metals. A selected metal is isolated and in a purified form in an aqueous raffinate phase from solvent extraction of nonselected metals using an organic phase containing a salt of an organic acid and the selected metal. Aqueous feed solution may result from leaching operations, including leaching of nickel-containing catalyst, such as catalyst used in hydrogenation of vegetable oils.
    Type: Grant
    Filed: October 15, 1992
    Date of Patent: March 21, 1995
    Assignee: Hazen Research, Inc.
    Inventor: Enzo Coltrinari
  • Patent number: 5370857
    Abstract: A process for producing stable, high purity ferrate (VI) employing beta-ferric oxide (beta-Fe.sub.2 O.sub.3), and preferably monohydrated beta-ferric oxide (beta-Fe.sub.2 O.sub.3.H.sub.2 O) as the iron source. An improved process for producing stable, high purity beta-ferric oxide is also disclosed. The process results in the efficient and effective productions of ferrate with high yields and small amounts of waste production. A large portion of the unused product stream can be recycled to the ferrate reactor for the production of additional ferrate.
    Type: Grant
    Filed: April 13, 1993
    Date of Patent: December 6, 1994
    Inventor: J. Paul Deininger
  • Patent number: 5364444
    Abstract: A process for extracting metals from a flotation concentrate containing gold, platinum group minerals, copper, nickel and sulfur. The process involves roasting the concentrate in the presence of oxygen to reduce the sulfur content of the concentrate to approximately two percent; leaching the roasted concentrate with an acid solution containing hydrochloric and nitric acids to dissolve substantially all of the metals; and recovering the metals from the solution.
    Type: Grant
    Filed: July 8, 1993
    Date of Patent: November 15, 1994
    Assignee: North American Pallidium Ltd.
    Inventors: C. Dale McDoulett, Jr., George W. Reschke
  • Patent number: 5336297
    Abstract: In a process for the treatment of electric arc furnace (EAF) dust, the dust is first subjected to atmospheric leaching with a ferric chloride solution and thereafter subjected to treatment in an autoclave at an elevated temperature and pressure for conversion of low temperature stable goethite (FeO.OH) to a filterable crystalline hematite (Fe.sub.2 O.sub.3) in an acidic chloride solution. Zinc is recovered from the solution by solvent extraction using a solvating extractant followed by stripping and zinc recovery by electrolysis of zinc chloride solution. Lead is separated from the solution by cooling to precipitate lead chloride.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: August 9, 1994
    Assignee: Terra Gaia Environmental Group Inc.
    Inventor: Roderick O. McElroy
  • Patent number: 5334362
    Abstract: In order to treat metal chlorides obtained in the form of dust collector solids in the production of titanium dioxide by the chloride process, the inert constituents, especially particulate coke, is separated then the metals are selectively precipitated and a maturing phase under oxidative conditions is provided for. The residue consisting of metal hydroxides is also not thixotropic in the absence of inerts. As a result, the material to be deposited has been cut in half.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: August 2, 1994
    Assignee: Kronos, Inc.
    Inventors: Dieter Schinkitz, Hans Thumm
  • Patent number: 5332531
    Abstract: Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: July 26, 1994
    Assignee: Arch Development Corporation
    Inventors: Earl P. Horwitz, Ralph C. Gatrone, Kenneth L. Nash
  • Patent number: 5332560
    Abstract: A method for the recovery of copper from copper-containing materials, for example, scrap, ores or dust. An aqueous cupric tetrammine sulfate lixiviant is contacted with the copper-containing material to produce a leachate containing cuprous, nickel, and zinc ions, ammonium sulfate and free ammonia. Copper can be recovered from the leachate by electrolysis. Nickel and zinc can be precipitated from the resulting spent electrolyte by oxidizing substantially all of the cuprous ions in the copper ammine sulfate solution to cupric ions and lowering the pH of the solution to a range from about pH 7.5 to about pH 8.0 in order to form a precipitate. Alternatively, copper sulfate can be added to the cupric ammine sulfate-containing solution in order to form nickel and/or zinc containing precipitate.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: July 26, 1994
    Assignee: Cato Research Corporation
    Inventors: William H. Kruesi, Paul R. Kruesi
  • Patent number: 5328670
    Abstract: A method of regenerating an etching waste fluid, includes the steps of dissolving HCl gas in an etching waste fluid at a temperature falling within a range of 20.degree. C. to 50.degree. C. and crystallizing NiCl.sub.2 and FeCl.sub.2 crystals, the etching waste fluid containing NiCl.sub.2, FeCl.sub.3, and FeCl.sub.2 and being obtained by etching Ni or an Ni alloy with an etching solution consisting of an aqueous solution containing FeCl.sub.3, distilling a mother liquor at the atmospheric pressure after crystallization and separation thereof to reduce the HCl concentration in the mother liquor, and distilling, at a reduced pressure, a concentrate obtained upon distillation at the atmospheric pressure to further reduce the HCl concentration, thereby obtaining an aqueous solution containing FeCl.sub.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: July 12, 1994
    Assignees: Nittetu Chemical Engineering, Ltd., Kabushiki Kaisha Toshiba
    Inventors: Teruhiko Hirabayashi, Yoshiyuki Imagire, Toshiaki Kurihara, Eiichi Akiyoshi, Ryoichi Maekawa
  • Patent number: 5320759
    Abstract: A process for selectively recovering dissolved heavy metals from a solution is disclosed that involves selectively reacting a xanthate with such dissolved heavy metals. Selective reaction of a xanthate with selected dissolved heavy metals is accomplished by conducting the reaction under conditions such that only some of the heavy metals react with the xanthate, to the exclusion of reaction with other dissolved heavy metals. Selectivity of the reaction is particularly influenced by the pH at which the reaction occurs. Typically, the reaction should occur at a pH below about 4.0. Xanthates, once reacted, can be separated from the heavy metal xanthate reaction product and recycled for use within the process. Purified heavy metal product can be produced if desired.
    Type: Grant
    Filed: June 11, 1992
    Date of Patent: June 14, 1994
    Assignee: Hazen Research, Inc.
    Inventor: Enzo Coltrinari
  • Patent number: 5308501
    Abstract: There is disclosed a method of treating a solution, e.g., an alkaline or acidic solution, containing heavy metals ions therein. With respect to alkaline solutions, the method includes providing a body of the solution; contacting the body with a material such as carbon dioxide to change the pH, e.g., to lower the pH to a pH in the range of 9 to 10.5; then treating the solution to further change the pH and cause precipitation of hydroxides, including chromium hydroxide; and separating the hydroxide precipitates from the solution to provide a substantially neutral solution having a reduced amount of chromium ions, for example, contained therein.
    Type: Grant
    Filed: April 2, 1993
    Date of Patent: May 3, 1994
    Inventor: C. Edward Eckert
  • Patent number: 5296151
    Abstract: A process is provided for the precipitation of phosphates from phosphate-comprising waters which utilizes iron hydroxide of the formula Fe.sub.2 O.sub.3.nH.sub.2 O wherein n=0.5-3.0. The iron hydroxide is prepared from natural or technical muds comprising iron in a process which involves dissolving with mineral acid and precipitation with a base. Other metal hydroxides are used together with the iron hydroxide.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: March 22, 1994
    Assignee: Industrie Automation Sondertechnik GmbH & Co.
    Inventors: German Muller, Siegfried Riethmayer
  • Patent number: 5238663
    Abstract: The invention relates to a process for recovering nickel from industrial effluents, characterized in thata) the effluent loaded with nickel is allowed to settle in a corrugated-plate separator (1) for the removal of solid constituents contained therein,b) a flocculant is added and the mixture is neutralized with alkali or mineral acid,c) after flocculation, the mixture is again allowed to settle in a corrugated-plate separator (3) andd) filtered through a sand filter (4),e) the filtered effluent is passed through a sequestering cation exchanger system containing three exchanger columns, the first column (5) being loaded up to breakthrough of nickel, the second column (6) serving as a guard filter and the third column (7) being regenerated or standing by in the freshly regenerated state,f) the particular column loaded with nickel is regenerated with dilute mineral acid, andg) the regenerate is treated with sodium hypophosphite in the presence of catalytic quantities of sodium borohydride, and to equipment for
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: August 24, 1993
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Werner Vikari, Ralf Steinstrasser, Heinrich Nikolaus, Gunther Feldmann-Schlohbohm, Klaus Behne
  • Patent number: 5234669
    Abstract: 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: Grant
    Filed: August 8, 1991
    Date of Patent: August 10, 1993
    Assignee: Idaho Research Foundation, Inc.
    Inventor: Robert W. Bartlett
  • Patent number: 5200042
    Abstract: A process for recovery of copper from a copper residue obtained during purification of a zinc sulfate solution comprises leaching the copper residue in a concentrated sulfuric acid solution in the presence of an oxidant at a temperature of between 60.degree. and 80.degree. C. and separating the solids from the leach solution, electrowinning copper from the leach solution, returning the electrolyte solution to the initial leaching stage to initiate dissolution of the copper residue, and bleeding a portion of the electrolyte solution to reduce the concentration of impurities in the solution.
    Type: Grant
    Filed: June 10, 1991
    Date of Patent: April 6, 1993
    Assignee: Noranda Inc.
    Inventors: George Houlachi, Carole Allen, Francis Belanger
  • Patent number: 5200159
    Abstract: A purified solution containing iron chloride and manganese chloride, having a phosphorus content not higher than about 0.007 wt. % with respect to the total content of iron and manganese. The method for producing the purified solution comprises the steps of dissolving manganese containing raw material in hydrochloric solution; oxidizing the solution; adjusting the pH of the solution to 2.5.about.4.5 to form insolubles; and separating the insolubles from the solution. This solution can be utilized to produce a mixed powder of an iron oxide and a manganese oxide. The mixed powder is useful for producing a high-quality soft ferrite.
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: April 6, 1993
    Assignees: Chemirite, Ltd., TDK Corporation
    Inventors: Naoe Hirai, Tohoru Murase, Teruo Mori, Katsunobu Okutani
  • Patent number: 5180563
    Abstract: A process for treating a sludge comprises digesting the waste material with a mixture of sulfuric acid and hydrogen peroxide to form an acidic digestion solution and a digestion residue. The digestion residue containing the major portion of tungsten and other refractory metals is reacted with NaOH to solubilize the major portion of tungsten values to a liquid concentrate that is separated from the insoluble solid that contains the major portion of the other refractory metals such as tantalum and niobium. The digestion solution containing the major portion of the transition and rare metals is treated with a base to selectively recover iron as a solid iron hydroxide precipitate which is separated from the resulting liquor. The liquor is then treated again with a base to selectively recover the other metals such as Sc, Cr, rare earths, but not Mn, as a solid metal hydroxide precipitate that is separated from the solution.
    Type: Grant
    Filed: October 24, 1989
    Date of Patent: January 19, 1993
    Assignee: GTE Products Corporation
    Inventors: Wen-Chao Lai, William J. Rourke, Samuel Natansohn
  • Patent number: 5178842
    Abstract: According to the method of the invention, at least one or several of the metals nickel, cobalt and copper can be selectively precipitated as sulphide by aid of elemental sulphur from aqueous solutions containing other metals such as zinc. The temperature of the reaction is above the melting point of sulphur. The precipitation is carried out with a pH value below 2. The metals to be precipitated can be present in the solution either as oxides or sulphates. If the metals are sulphates, the sulphide of at least one of the metals is prepared to crystal seeds in the solution before precipitation.
    Type: Grant
    Filed: October 26, 1988
    Date of Patent: January 12, 1993
    Assignee: Outokumpu Oy
    Inventor: Sigmund P. Fugleberg
  • Patent number: 5167940
    Abstract: A method and apparatus for treating a catalytic polyvalent metal redox absorption solution, after absorption of H.sub.2 S from a gas, in a first hydrothermal treatment, to separate the polyvalent metal, for example as a polyvalent metal sulfide precipitate, and thereafter treating the redox solution in a higher temperature hydrothermal treatment to decompose thiosulfate salts and, if present, thiocyanide and other cyanide salts and metal-cyanide complexes to decompose the salts and complexes to molecules that can be treated in the H.sub.2 S-absorption process for recovery of sulfur and alkali values.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: December 1, 1992
    Assignee: ARI Technologies Inc.
    Inventor: Derek McManus
  • Patent number: 5160482
    Abstract: A process for the recovery of substantially pure zirconium values from zircon sand which also contains Ra, U, Hf, Pb and other metal values, comprising contacting zircon sand in a chlorinator with a chlorination medium to form an off-gas stream containing chlorides of Zr, Hf, Si, and tract U. The off-gas stream is passed to a condenser to remove volatile Si chlorides and thereby provide a product stream containing condensed chlorides of Zr, Hf and tract U, treating the product stream in acidic aqueous medium in a separation stage to separate the principal Hf values from the principal Zr values. Adjusting the pH of the resulting effluent to between about 3 to about 7 in a second stage to precipitate the trace U values. The residue stream is treated by(A) leaching with an acidic aqueous system to solubilize the trace Ra, Pb and other metal values while settling out the unreacted zircon sand and chlorination medium, and contacting the resultant leach liquor first with Ba++ ions and then with SO.sub.
    Type: Grant
    Filed: March 2, 1989
    Date of Patent: November 3, 1992
    Assignee: Teledyne Industries, Inc.
    Inventors: Kenneth C. Ash, William A. Crocker, John C. Haygarth, David R. Lee, Donald Morris, John R. Peterson, Jon A. Riesen, Robert S. Yih
  • Patent number: 5160631
    Abstract: A process for removing at least a portion of any iron, copper, nickel and chromium ions that are chelated by a alkylenepolyamine polyacetic acid or salt in an aqueous liquid waste. The process comprises the steps of (a) adjusting the pH of the liquid to above about 10; (b) adding sufficient sodium sulfide to react with at least a portion of the copper ions; (c) separating precipitated iron and copper compounds; (d) adding nitric acid to adjust the pH to the range of about 6 to 8; (e) adding sufficient sodium nitrite to the liquid to react with at least a portion of the nickel and chromium present; (f) heating the liquid to above about 575.degree. F. for at least about 15 minutes to facilitate precipitation of nickel and chromium; and (g) separating precipitated solids to leave a non-hazardous filtrate.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: November 3, 1992
    Assignee: Halliburton Company
    Inventors: Jack G. Frost, Kenneth J. Snyder
  • Patent number: 5130107
    Abstract: Cobalt is recovered from the oil/water mixed reaction product of oxonation by increasing the carbon dioxide level in the reaction product and adjusting the temperature to enhance the carbon dioxide level in the oil water phase to promote the formation of cobalt carbonate which is allowed to settle and may be removed and/or recycled increasing cobalt utilization and reducing environmental problems.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: July 14, 1992
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Nicolaas A. De Munck, Mattheus D. Olijve, Raf Caers, Arie Van Vliet, Jean A. A. Hanin, Eddy Van Driessche
  • Patent number: 5102633
    Abstract: A method for reducing impurity levels of calcium, magnesium and/or silicon in hexammine cobalt halide compounds involves the addition of ferric ions and, optionally, soluble fluorides to an aqueous hexammine cobalt (III) chloride solution having a pH of at least 9. Insoluble compounds of magnesium fluoride, calcium fluoride, and/or ferric hydroxide and silicon coprecipitates are removed from the solution by filtration.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: April 7, 1992
    Assignee: GTE Products Corporation
    Inventors: Eric F. Husted, Michael J. Miller, Shellie K. Northrop, David T. Smith
  • Patent number: 5102640
    Abstract: 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: Grant
    Filed: June 29, 1990
    Date of Patent: April 7, 1992
    Inventor: Carl W. Schlapfer
  • Patent number: 5082638
    Abstract: The invention relates to a process for recovering non-ferrous metal values such as nickel, cobalt, copper, zinc, manganese and magnesium from material containing said metals, by converting the non-ferrous metal values into sulphates by using melt and melt coating sulphation and recovering them as metal compounds by a process entity based on a melt and melt coating sulphation.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: January 21, 1992
    Inventors: Pekka J. Saikkonen, Jussi K. Rastas
  • Patent number: 5057290
    Abstract: Processes and apparatus for the closed-loop regeneration of spent hydrochloric acid pickle liquors that have been used to pickle ferrous metals by recovering ferrous chloride from the spent pickle liquors at very low temperatures. The process includes maintaining the hydrochloric acid and iron concentrations within the spent pickle liquor at levels that will prevent the liquor from freezing when cooled to about -10 degrees Fahrenheit and that will permit the formation of ferrous chloride crystals within the spent pickle liquor when the liquor is cooled below about +18 to 20 degrees Fahrenheit and to about -10 degrees Fahrenheit. The ferrous chloride crystals formed at such low temperatures are then removed from the pickle liquor, which then permits reuse of the free hydrochloric acid remaining within the thus regenerated pickle liquor in normal pickling operations.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: October 15, 1991
    Inventors: Joseph C. Peterson, George A. Salof
  • Patent number: 5057299
    Abstract: Beta cobaltous hydroxide is synthesized by decomposing the complex formed between cobaltous ions and a suitable complexing agent under hydrothermal conditions. Cobaltous ion and complexing agent are combined in an aqueous medium, wherein the molar ratio of the cobaltous ion to the complexing agent is about one or more. Hydroxide ion is added, wherein the molar ratio of hydroxide ion to cobaltous ion is more than about 2. The resulting admixture is heated under hydrothermal conditions for precipitating beta cobaltous hydroxide. The method provides improved control over the size and shape of the beta cobaltous hydroxide reaction product. The beta cobaltous hydroxide can be reduced to form magnetic particles of cobalt metal.
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: October 15, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Jean A. Lown
  • Patent number: 5057469
    Abstract: Iron nitrosyl carbonyl catalyst is prepared by dissolving impure iron nitrosyl carbonyl in a solvent solution, then adding sufficient miscible non-solvent to the solution to result in separation of the mixture into an upper layer and a lower layer containing iron nitrosyl carbonyl. Preferably, the solvent is used in preparation of the iron nitrosyl carbonyl, and the solution is, therefore, the product of the preparation. The miscible non-solvent is added to the product solution to effect separation of layers for isolation of purified iron nitrosyl carbonyl product.
    Type: Grant
    Filed: September 5, 1990
    Date of Patent: October 15, 1991
    Assignee: The Dow Chemical Company
    Inventor: Duane E. Heaton
  • Patent number: 5032367
    Abstract: A method for producing a powdered iron oxide comprises the steps of adjusting the pH of a crude iron chloride solution to 2.5-4.5; reducing the P content of the solution by mechanical stirring or air bubbling and filtering; and oxidizing the solution into a powdered iron oxide having a maximum P content of 0.005 wt. %. The P content of the solution may also be reduced by ultrafilter treatment. The soft ferrite made by using the powdered iron oxide by this process shows excellent magnetic properties.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: July 16, 1991
    Assignees: Chemirite, Ltd., TDK Corporation
    Inventors: Naoe Hirai, Tohoru Murase, Katsunobu Okutani, Teruo Mori
  • Patent number: 5009793
    Abstract: A process for the heavy-metal decontamination of contaminated substances such as natural and industrial sludges, thermal residues and soils. The contaminated starting substance is treated with an acid and the dissolved metal salts are precipitated as metal hydroxides in the pH range of about 3.5-11. The exact control of the pH value makes it possible to isolate individual metal fractions which can be used as raw materials in the metallurgical industry.
    Type: Grant
    Filed: January 9, 1990
    Date of Patent: April 23, 1991
    Assignee: Industrie Automation Sondertechnik GmbH & Co.
    Inventor: German Muller