Arsenate Patents (Class 423/602)
  • Patent number: 8852464
    Abstract: Electrically conducting vanadium arsenate or vanadium phosphate materials are described. The materials include a vanadium arsenate or vanadium phosphate framework structure about organic template and water molecules which may be removed to leave a microporous structure. The three-dimensional vanadium framework may provide electronic conductivity, while the extra-framework constituents may provide ionic conductivity.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: October 7, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Victoria Soghomonian, Jean J. Heremans
  • Patent number: 8465723
    Abstract: Provided is an arsenic-containing solid comprising 100 parts by mass of a scorodite-type iron-arsenic compound and at least 1 part by mass of an iron oxide compound added thereto, in which the scorodite-type iron-arsenic compound is produced by adding an oxidizing agent to an aqueous acidic solution that contains a 5-valent arsenic (V) ion and a 2-valent iron (II) ion, then promoting the precipitation of an iron-arsenic compound with stirring the liquid, and finishing the precipitation thereof within a range where the pH of the liquid is at most 1.2. The iron oxide compound includes goethite, hematite and their mixture, preferably having a BET specific surface area of at least 3 m2/g, more preferably at least 20 m2/g.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: June 18, 2013
    Assignee: Dowa Metals & Mining Co., Ltd.
    Inventors: Tetsuo Fujita, Ryoichi Taguchi, Hisashi Kubo
  • Patent number: 8092764
    Abstract: Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: January 10, 2012
    Assignee: Dowa Metals and Mining Co., Ltd.
    Inventors: Mitsuo Abumiya, Yusuke Sato, Hironobu Mikami, Masami Oouchi, Tetsuo Fujita, Masayoshi Matsumoto
  • Patent number: 8075868
    Abstract: There is provided an iron arsenate powder which is produced from an arsenic containing solution and wherein the concentration of arsenic eluted or released from the powder is very low. The iron arsenate powder is a powder of dihydrate of iron arsenate, which has a crystal structure of rhombic system and which has lattice constants of a=0.8950 to 0.8956 nm, b=1.0321 to 1.0326 nm and c=1.0042 to 1.0050 nm at room temperatures and atmospheric pressure. The iron arsenate powder can be produced by a method comprising the steps of: adding ferrous ions to an arsenic containing solution to cause the molar ratio (Fe/As) of iron to arsenic in the solution to be not lower than 1; adding an oxidizing agent to the solution; heating the solution to a temperature of not lower than 70° C. while stirring the solution, to allow a reaction; and carrying out a solid-liquid separation to wash the obtained solid part.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: December 13, 2011
    Assignees: Dowa Metals & Mining Co., Ltd., Tohoku University
    Inventors: Tetsuo Fujita, Takashi Nakamura, Shigeru Suzuki, Kozo Shinoda
  • Patent number: 7897135
    Abstract: The present invention is generally directed to a novel, economic synthesis of oxide ceramic composites. Methods of the present invention, referred to as carbon combustion synthesis of oxides (CCSO), are a modification of self-propagating high-temperature synthesis (SHS) methods in which the heat needed for the synthesis is generated by combustion of carbon in oxygen rather than that of a pure metal. This enables a more economic production of the ceramic material and minimizes the presence of intermediate metal oxides in the product. The reactant mixture generally comprises at least one oxide precursor (e.g., a metal or non metal oxide, or super oxide, or nitride, or carbonate, or chloride, or oxalate, or halides) as a reactant, but no pure metal. Pure carbon in the form of graphite or soot is added to the reactant mixture to generate the desired heat (upon ignition). The mixture is placed in a reactor and exposed to gaseous oxygen.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: March 1, 2011
    Assignee: University of Houston
    Inventors: Karen S. Martirosyan, Dan Luss
  • Publication number: 20100196231
    Abstract: The object is to remove arsenic in a stable form from an arsenic-containing smelting intermediate product. Thus, disclosed is a method for treating an arsenic-containing nonferrous smelting intermediate product, which comprises: a leaching step of subjecting a mixed slurry of a nonferrous smelting intermediate product containing arsenic in the form of a sulfide and a nonferrous smelting intermediate product containing arsenic and metal copper to the oxidation/leaching in an acidic range to produce a leaching solution; a solution preparation step of adding an oxidizing agent to the leaching solution to oxidize trivalent arsenic into pentavalent arsenic, thereby producing a preparation solution; and a crystallization step of converting arsenic contained in the preparation solution into a scorodite crystal.
    Type: Application
    Filed: July 11, 2008
    Publication date: August 5, 2010
    Applicant: DOWA METALS & MINING CO., LTD.
    Inventors: Mitsuo Abumiya, Yusuke Sato, Hironobu Mikami, Masami Oouchi, Tetsuo Fujita, Masayoshi Matsumoto
  • Publication number: 20100196230
    Abstract: Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.
    Type: Application
    Filed: July 11, 2008
    Publication date: August 5, 2010
    Applicant: DOWA METALS & MINING CO., LTD.
    Inventors: Mitsuo Abumiya, Yusuke Sato, Hironobu Mikami, Masami Oouchi, Tetsuo Fujita, Masayoshi Matsumoto
  • Patent number: 7338647
    Abstract: The present invention relates to a method for preparing an electroactive metal polyanion or a mixed metal polyanion comprising forming a slurry comprising a polymeric material, a solvent, a polyanion source or alkali metal polyanion source and at least one metal ion source; heating said slurry at a temperature and for a time sufficient to remove the solvent and form an essentially dried mixture; and heating said mixture at a temperature and for a time sufficient to produce an electroactive metal polyanion or electroactive mixed metal polyanion.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: March 4, 2008
    Assignee: Valence Technology, Inc.
    Inventors: Biying Huang, Jeffrey Swoyer, M. Yazid Saidi, Haitao Huang
  • Patent number: 7261906
    Abstract: A process for preparing As4O6 comprises successively heating and cooling a mixture of natural Sinsuk and 40% alcohol in a ratio of about 1: about 1 for about 1 to about 2 hour(s) resulting in a product, successively washing the product with distilled water thereby forming washed precipitates, maintaining the washed precipitates at about ?40° C. for 24 hours, defrosting, filtering, and drying the precipitates, and successively heating and cooling the precipitates to obtain the final As4O6 product.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: August 28, 2007
    Inventors: Ill-Ju Bae, Jong-Bae Kim, Choong-Ki Eun, Seung-Kyu Song, Byung-Sun Suh, Kwan-Hee Lee, Myoung-Sool Doo, Jin-Hwan Kwak, Byung-Doo Song, Taek-Joon Yoon, Tae-Bong Kang, Choon-Ho Park
  • Patent number: 7255962
    Abstract: Improved solid acid electrolyte materials, methods of synthesizing such materials, and electrochemical devices incorporating such materials are provided. The stable electrolyte material comprises a solid acid in a eulytine structure capable of undergoing rotational disorder of oxyanion groups and capable of extended operation at elevated temperatures, that is, solid acids having hydrogen bonded anion groups; a superprotonic disordered phase; and capable of operating at temperatures of ˜100° C. and higher.
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: August 14, 2007
    Assignee: California Institute of Technology
    Inventors: Calum Chisholm, Sossina M. Haile
  • Patent number: 6890500
    Abstract: The invention is directed to open-framework and microporous solids well suited for use in catalysis and ion exchange. The microporous solids are constructed by using a salt template which can be readily removed without destroying the framework of the micropore. Various microporous solids can be formed having different geometric structures depending upon the templating salt used and the concentration. Examples of two compounds include Na2Cs[Mn3(P2O7)2]Cl and K2.02Cs2.90[Cu3(P2O7)2]Cl2.92. Both compounds have 3-D (Mn, Cu)—P—O frameworks.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: May 10, 2005
    Assignee: Clemson University
    Inventors: Shiou-Jyh Hwu, Qun Huang, Mutlu Ulutagay
  • Patent number: 6821434
    Abstract: Systems for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical systems for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A system for continuous removal of arsenic from water is provided. Also provided is a system for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: November 23, 2004
    Assignee: Sandia Corporation
    Inventors: Robert C. Moore, D. Richard Anderson
  • Patent number: 6719955
    Abstract: The invention is directed to open-framework and microporous solids well suited for use in catalysis and ion exchange. The microporous solids are constructed by using a salt template which can be readily removed without destroying the framework of the micropore. Various microporous solids can be formed having different geometric structures depending upon the templating salt used and the concentration. Examples of two compounds include Na2Cs[Mn3(P2O7)2]Cl and K2.02Cs2.90[Cu3(P2O7)2]Cl2.92. Both compounds have 3-D (Mn,Cu)—P—O frameworks.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: April 13, 2004
    Assignee: Clemson University
    Inventors: Shiou-Jyh Hwu, Qun Huang, Mutlu Ulutagay
  • Patent number: 6682712
    Abstract: The present invention provides a novel thermal solid state method for the synthesis of lithium hexfluoroarsenate either in a two step or a single step method, preferably at last substantially in the solid state.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: January 27, 2004
    Assignee: Council of Scientific & Industrial Research
    Inventors: Subramanian Angaiah, Vasudevan Thiagarajan, Gnagadharan Ramaiyer, Raghavan Meenakshisundaram
  • Publication number: 20030185745
    Abstract: The present invention provides a novel solid state method for the synthesis of lithium meta arsenate (LiAsO2) by mixing a lithium source with arsenious trioxide under controlled conditions to obtain the lithium meta arsenate.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 2, 2003
    Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Subramanian Angaiah, Vasudevan Thiagarajan, Gnagadharan Ramaiyer, Raghavan Meenakshisundaram
  • Patent number: 6616744
    Abstract: The present invention provides a method of forming inorganic pigments using one or more metal alloys. Metal alloys used in the method of the invention are preferably milled to a mean particle size of less than about 10 microns, may be mixed with other metal oxides, and calcined in the presence of oxygen in a rotary kiln. Inorganic pigments formed in accordance with the method of the invention can be used in a wide variety of applications, including the coloration of glass matrixes, ceramic bodies, polymers, and paints.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: September 9, 2003
    Assignee: Ferro Corporation
    Inventors: Javier Garcia Sainz, Rosario Blanch Castello, Rafael Mena Pla, Juan Carlos Gallart
  • Patent number: 6613926
    Abstract: Novel compounds are provided in the form of nucleoside pyrophosphate and triphosphate analogs. In these analogs, the pyrophosphate or triphosphate group is replaced with a moiety that is isosterically and electronically identical thereto, but is hydrolytically and enzymatically more stable. The compounds are useful as therapeutic agents, e.g., as antiviral agents, anticancer agents, metabolic moderators and the like. The invention also provides pharmaceutical compositions containing a compound of the invention as an active agent, and in addition provides methods of treating disease, including viral infections, cancer, bacterial infections, inflammatory and/or autoimmune diseases, and the like, by administering a compound of the invention to a patient in need of such treatment.
    Type: Grant
    Filed: November 1, 2000
    Date of Patent: September 2, 2003
    Assignee: SRI International
    Inventors: Jeffrey C. Bottaro, Robert J. Schmitt, Mark A. Petrie, Paul E. Penwell
  • Patent number: 6177015
    Abstract: An aqueous solution, for example, effluent from an off-gas scrubber, is treated to remove metal and metalloid ions by in situ precipitation of ferrous ions by the addition thereto of a ferrous ion-containing solution, salt or other such ferrous ion-containing source and a hydroxyl-yielding base in the presence of the metals and metalloids. The reaction conditions include a temperature of at least about 60° C., and a pH of from about 6 to about 10.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: January 23, 2001
    Assignee: Inco Limited
    Inventors: Brian Charles Blakey, Justin Raskauskas
  • Patent number: 5411723
    Abstract: A process is disclosed for treating a crystal of MTiOXO.sub.4 which has crystal structure deficiencies of M and O, wherein M is selected from the group consisting of K, Rb, Tl and NH.sub.4 and mixtures thereof and X is selected from the group consisting of P, As and mixtures thereof, which includes the step of heating said crystal in the presence of a mixture of MTiOXO.sub.4 and at least one inorganic compound of one or more monovalent cations selected from the group consisting of Rb+, K+, Cs+ and Ti+ (said inorganic compound(s) being selected to provide a source of vapor phase monovalent cation and being present in an amount sufficient to provide at least a 0.1 mole % excess of the monovalent cation in relation to the M in the MTiOXO.sub.4 in said mixture) at a temperature of from about 400.degree. C. to 950.degree. C. and a pressure of at least 14 psi, and in the presence of a gaseous source of oxygen for a time sufficient to decrease the optical damage susceptibility of said crystal.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: May 2, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Patricia A. Morris
  • Patent number: 5348662
    Abstract: In the process of removing heavy metals from aqueous solutions (groundwater) by precipitation of a salt thereof, an oxidizing agent is optionally used to increase the valence of said metal, and a precipitation-enhancing agent is added to maximize particle size of the precipitate and to facilitate its separation from said solution.
    Type: Grant
    Filed: May 13, 1993
    Date of Patent: September 20, 1994
    Assignee: Elf Atochem North America, Inc.
    Inventors: Jeffrey H. Yen, Richard C. Spung
  • Patent number: 5344479
    Abstract: A process is disclosed for separating and recovering nickel and copper values from a nickel-copper matte which may contain iron and arsenic. Finely divided nickel-copper matte is leached in aqueous sulphuric acid solution under oxidizing conditions at atmospheric pressure and at a minimum temperature of about 80.degree. C. to selectively leach nickel from the matte to produce a nickel sulphate solution having a final pH in the range of about 4.0 to 6.5, preferably about 6.5, and to produce a copper-rich sulphide residue. The copper-rich sulphide residue is separated from the nickel sulphate solution and leached in a closed reaction vessel at a minimum temperature of about 120.degree. C. under a non-oxidizing atmosphere in a sulphuric acid solution containing an effective amount of copper and sulphuric acid to provide a terminal concentration of at least about 2 g/L Cu.sup.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: September 6, 1994
    Assignee: Sherritt Gordon Limited
    Inventors: Derek G. E. Kerfoot, Rein Raudsepp
  • Patent number: 5281405
    Abstract: A sol-gel process is disclosed for preparing MTiOXO.sub.4 when M is K, Rb, Tl and/or NH.sub.4 and X is P and/or As which involves dissolving suitable compounds of M, Ti and X in stoichiometic amounts in a suitable organic liquid, and then producing crystalline MTiOXO.sub.4 using procedures including hydrolysis, condensation, solidification and pyrolysis. Bulk material and films (e.g., films of KTP on a single crystal silicon substrate) may be produced. Compositions comprising films of said MTiOXO.sub.4 produced by this process are disclosed.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: January 25, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Mark A. Harmer
  • Patent number: 5262063
    Abstract: In the process of removing heavy metals from aqueous solutions by precipitation of a salt thereof at increased pH, multiple stage precipitation by upward stepwise pH adjustment and solid separation at each stage is used to facilitate the manufacture of a product of high purity.
    Type: Grant
    Filed: May 14, 1992
    Date of Patent: November 16, 1993
    Assignee: Elf Atochem North America, Inc.
    Inventor: Jeffrey H. Yen
  • Patent number: 5141753
    Abstract: The invention relates to a method for producing wood anti-rot agent of the copper-arsenic precipitate created in the solution purification of copper electrolysis, or of some other corresponding precipitate.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: August 25, 1992
    Assignee: Outokumpu Oy
    Inventors: Henri K. Virtanen, Leo E. Lindroos
  • Patent number: 5137640
    Abstract: A process for reducing arsenic levels in a solution containing sulfuric acid, water, and arsenic acid by adding copper or a copper-containing compound to the solution to form dissolved copper arsenate, adding alkali solution to precipitate the copper arsenate and to neutralize arsenic and sulfuric acid. The copper arsenate is separated, and the remaining solution is treated with a ferric compound and an alkali in order to form ferric arsenate to remove residual arsenate. The ferric arsenate is separated and the remaining solution contains less than about 0.79 ppm arsenic. The ferric compound is added so that the ratio of iron to arsenic is about 8:1 to about 10:1 and alkali is added during this step to adjust the pH to from about 5 to about 7.
    Type: Grant
    Filed: May 6, 1991
    Date of Patent: August 11, 1992
    Assignee: Allied-Signal Inc.
    Inventor: Rustom P. Poncha
  • Patent number: 5126116
    Abstract: 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: Grant
    Filed: June 17, 1991
    Date of Patent: June 30, 1992
    Assignee: Inco Limited
    Inventors: Eberhard Krause, Vladimir J. Zatka, Steven W. Laundry
  • Patent number: 5114592
    Abstract: The invention involves a process as well as apparatus for the separation of arsenic from waste material. The process includes precipitation of arsenic in the form of low solubility calcium magnesium arsenates by adding calcium and magnesium compounds to the waste, separation of calcium magnesium arsenates, putting the waste in contact with an ion exchanger, regenerating the ion exchanger after reaching the charge limit, adsorptively separating the arsenic by putting the waste in contact with active carbon, and separating the charged active carbon by itself or along with precipitation products. The process allows for a separation of arsenic from waste which is hard to be treated or contains heavy metals such as lead or contains sulfates to residual amounts as low as <0.3 mg As/l.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: May 19, 1992
    Assignee: Walhalla-Kalk, Entwichlungs- und Vertriebsgesellschaft mbH
    Inventors: Georg Schuster, Hans Kaestle
  • Patent number: 5093007
    Abstract: An improved process for removal of soluble contaminants from wastewater is disclosed which provides significantly enhanced contaminant removal and overall process efficiencies. The improved contaminant removal process is especially suitable for treatment of industrial effluents having high levels of dissolved cyanide and arsenic contaminants. Wastewater undergoes multiple stage sludge treatment, wherein sludge is mixed with wastewater sequentially in a plurality of discrete reaction stages for relatively short retention times. Reaction conditions which promote chemical and/or physical reaction of soluble contaminants with sludge are maintained, and liquid/solids separation is effected after each sludge treatment stage. Oxidizing agent is preferably mixed with the wastewater prior to multiple stage sludge treatment to change the oxidation state of inorganic contaminants and remove cyanide contaminants from solution.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: March 3, 1992
    Assignee: NERCO Minerals Company
    Inventor: Serena J. Domvile
  • Patent number: 5072031
    Abstract: Layered divalent metal pentavalent metallate, M(HAO.sub.4).sub.x (RAO.sub.3).sub.y (Z).sub.z wherein M is divalent metal, A is a pentavalent metal, e.g. phosphorus, R is a substituent group other than H or OH, e.g., phenyl, covalently bonded to A, x+y=1, y is greater than 0, z ranges from 0 to 2, inclusive, and Z is an intercalated moiety is prepared by contacting a source of divalent metal with a substituted phosphonic acid-type compound under hydrothermal conditions.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: December 10, 1991
    Assignee: Mobil Oil Corp.
    Inventor: Stuart D. Hellring
  • Patent number: 5026530
    Abstract: A method of preparing copper arsenate compositions having unique advantges in lower cost and higher performance for use in preparing chromated copper arsenate wood preserving formulations. These copper arsenate compositions are insoluble copper arsenate in water or as a dry reactive powder, have a mol ratio of As.sub.2 O.sub.5 to CuO of 1:4, and is readily soluble in chromic acid to form CCA wood preservatives. This copper arsenate is prepared by reacting suitable copper-bearing materials with arsenic trioxide and air or oxygen in ammoniacal solutions. Either or both of the starting raw materials, i.e., the copper and the arsenic, may be very impure, which impure materials were heretofore unsuitable for the production of copper arsenate.
    Type: Grant
    Filed: March 30, 1990
    Date of Patent: June 25, 1991
    Assignee: Drinkard Developments
    Inventors: William F. Drinkard, Jr., Hans J. Woerner
  • Patent number: 5002748
    Abstract: Copper arsenate, substantially free from impurities that form sludge in wood preservatives such as chromated copper arsenate, is prepared by adding a solution of soluble arsenate to copper sulfate solution, either or both solutions containing sludge-forming impurities, to form a copper and arsenic-containing solution without precipitating copper arsenate. The pH during the adding is controlled at a value in the range of 1.8 to 2.2 to precipitate impurities. Precipitated impurities are removed, and the copper and arsenic-containing solution is neutralized with a suitable alkaline substance to pH 3.5 to 5.0 to precipitate copper arsenate. Arsenate solution is derived from arsenic oxides, soluble arsenic salts and compounds and metallurgical materials capable of yielding water-soluble arsenate. Copper sulfate solution is derived from crystals and compounds and metallurgical materials cable of yielding copper sulfate.
    Type: Grant
    Filed: September 2, 1988
    Date of Patent: March 26, 1991
    Assignee: Cominco Ltd.
    Inventors: David L. Jones, Edward F. G. Milner
  • Patent number: 4961909
    Abstract: In a process for the manufacture of copper arsenate, an arsenic-containing material is subjected to an oxidative pressure leach with sodium hydroxide forming a leach solution containing sodium arsenate. Sodium arsenate solution is mixed with a solution of copper sulfate for the formation of a copper and arsenic-containing solution without the precipitation of copper arsenate. The copper and arsenic-containing solution is treated for the precipitation of copper arsenate with formation of sodium sulfate solution. At least one of the sodium arsenate-containing solution and the sodium sulfate solution is subjected to electrolysis with membrances for at least partial conversion to arsenic acid and sulfuric acid, respectively, and sodium hydroxide.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: October 9, 1990
    Assignee: Comino Ltd.
    Inventor: Daniel A. D. Boateng
  • Patent number: 4962228
    Abstract: Layered divalent metal pentavalent metallate, M(HAO.sub.4).sub.x (RAO.sub.3).sub.y (Z).sub.z wherein M is divalent metal, A is a pentavalent metal, e.g. phosphorus, R is a substituent group other than H or OH, e.g., phenyl, covalently bonded to A, x+y=1, y is greater than O, z ranges from 0 to 2, inclusive, and Z is an intercalated moiety is prepared by contacting a source of divalent metal with a substituted phosphonic acid-type compound under hydrothermal conditions.
    Type: Grant
    Filed: December 29, 1987
    Date of Patent: October 9, 1990
    Assignee: Mobil Oil Corporation
    Inventor: Stuart D. Hellring
  • Patent number: 4959203
    Abstract: Copper arsenate, substantially free from impurities that will form a sludge in the process for producing wood preservatives such as chromated copper aresenate and having a water content of less than 15%, is prepared by mixing a solution of soluble arsenate and a copper sulfate solution, either or both solutions containing sludge-forming impurities, to form a copper and arsenic-containing solution without precipitating copper arsenate. The pH during the adding is controlled at a value in the range of 1.7 to 2.2 to precipitate impurities. Precipitated impurities are removed, and the copper and arsenic-containing solution is neutralized with a suitable alkaline substance, preferably dilute sodium hydroxide solution, to pH 3.2 to 4.2 to precipitate copper arsenate.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: September 25, 1990
    Assignee: Cominco Ltd.
    Inventors: Susan B. Knoerr, Robert G. Robins
  • Patent number: 4891067
    Abstract: A process for the treatment of flue dust from copper and lead smelters includes the steps of subjecting a slurry (10) of water and flue dust to a first caustic leach (12) to form a first liquids soluble sulfate solution (14) and a first solids portion (15), subjecting the solids portion to a second caustic leach (16) to solubilize lead and arsenic in a second liquid portion (22) and, selectively extracting the arsenic from the second liquid portion by precipitation (23).
    Type: Grant
    Filed: May 13, 1988
    Date of Patent: January 2, 1990
    Assignee: Kennecott Utah Copper Corporation
    Inventors: Alkis S. Rappas, Brett T. Waterman
  • Patent number: 4878945
    Abstract: 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: Grant
    Filed: September 18, 1987
    Date of Patent: November 7, 1989
    Inventors: Rein Raudsepp, Morris J. Beattie
  • Patent number: 4842698
    Abstract: A potentiometric electrochemical sensor for detecting gaseous concentrations of arsenic oxides or arsenic-bearing species at elevated temperatures. The sensor is comprised of: an ionically conducting solid state membrane which may be made of silver zirconium arsenate, sodium beta-alumina or silver beta-alumina; a reference electrode which may be silver wire packed in silver powder; and a working electrode which may consist of a platinum mesh electrode or a silver wire exposed to the arsenic oxide-bearing gas. The probe is responsive to arsine [AsH.sub.3 ] concentrations in the range 5-1000 ppm in oxidizing gases, such as air, which have been raised to the temperature range 600.degree.-900.degree. C. The compound silver zirconium arsentate is also novel.
    Type: Grant
    Filed: May 19, 1987
    Date of Patent: June 27, 1989
    Assignee: Canadian Patents and Development Limited/Societe Canadienne des Brevets et d'Exploitation Limitee
    Inventors: Jitka Kirchnerova, James M. Skeaff, Christopher W. Bale
  • Patent number: 4804494
    Abstract: A copper arsenate composition suitable for incorporation in a copper/chrome/arsenic wood preservative composition is made by reacting copper metal with a source of 5-valent arsenic such as arsenic acid under the oxidizing influence of hydrogen peroxide. The quantity of arsenic acid used may be made consistent with the arsenic to copper ratio required in the final wood preservative composition which may be made up by including a suitable source of chromium with the copper arsenate reaction product.
    Type: Grant
    Filed: April 23, 1987
    Date of Patent: February 14, 1989
    Assignee: Laporte Industries Limited
    Inventors: Ian K. Egerton, Andrew D. J. Broome
  • Patent number: 4655829
    Abstract: Metal values are separated from arsenic sulfide ores in a hydrometallurgical oxidation process using a balanced reactant slurry. The molar concentration of As and Sb in the reactant slurry is controlled with respect to the molar concentration of Cu, Pb, and Zn in the slurry so that, upon reacting, soluble arsenic compounds or toxic arsenic vapors are not formed.
    Type: Grant
    Filed: September 11, 1985
    Date of Patent: April 7, 1987
    Assignee: CSS Management Corp.
    Inventor: Joseph B. Cashman
  • Patent number: 4647307
    Abstract: A process for the hydrometallurgical recovery of precious metal from an ore or concentrate containing at least some arsenopyrite or pyrite.
    Type: Grant
    Filed: November 14, 1985
    Date of Patent: March 3, 1987
    Inventors: Rein Raudsepp, Ernest Peters, Morris J. V. Beattie
  • Patent number: 4629656
    Abstract: Ion exchange inorganic films made up of alpha-type or gamma-type layered structure insoluble acid salts of tetravalent metals or their salt forms, or their intercalated forms or their organic derivatives containing polar groups. A process for the preparation of said films.
    Type: Grant
    Filed: May 13, 1985
    Date of Patent: December 16, 1986
    Assignee: Consiglio Nazionale Delle Ricerche
    Inventors: Giulio Alberti, Umberto Costantino
  • Patent number: 4610723
    Abstract: A process for lixiviation of concentrates of copper sulphides of tetrahedral type containing high concentration of arsenic and antimony to recover copper and noble metals. The concentrates are repulped into an aqueous ferrous sulphate solution with an established and controlled solid-liquid ratio which is thereafter oxidized by an oxygen containing gas in a reactor, thereby oxidizing the sulphides to sulphates, precipitating iron as ferric arsenates and antimoniates and yielding a lixiviation pulp in which the solid phase contains the iron, antimony and arsenic as well as the insoluble sulphates of the non-ferrous metals, such as lead and noble metals, and the liquid phase containing the copper, free sulphuric acid and the soluble sulphates of non-ferrous metals, as well as zinc, cadmium, cobalt, etc. The metals contained therein are recovered, after solid-liquid separation by conventional method.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: September 9, 1986
    Inventors: Eduardo D. Nogueira, Angel L. Redondo Abad
  • Patent number: 4405569
    Abstract: 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: Grant
    Filed: November 4, 1981
    Date of Patent: September 20, 1983
    Assignee: Sulpetro Minerals Limited
    Inventor: Ulrich Dienstbach
  • Patent number: 4376709
    Abstract: New intercalated compounds comprising a cation intercalated in a layered mixed oxide, said oxide having layers of corner linked octahedra and tetrahedra. The composition has the formula A.sub.q MOXO.sub.4.nH.sub.2 O where A is a monovalent, divalent or polyvalent cation, MOXO.sub.4 is a layered mixed oxide selected from the group consisting of VOPO.sub.4, VOSO.sub.4, VOAsO.sub.4, VOMoO.sub.4, NbOPO.sub.4, NbOAsO.sub.4, TaOPO.sub.4 and MoOPO.sub.4, n is a number from 0 to 4 and q is a number from about 0.001 to about 1.0.
    Type: Grant
    Filed: November 10, 1980
    Date of Patent: March 15, 1983
    Assignee: Exxon Research and Engineering Co.
    Inventors: Jack W. Johnson, Allan J. Jacobson
  • Patent number: 4369164
    Abstract: A process for leaching copper and arsenic from copper dross containing copper arsenide and separated from molten lead bullion comprises leaching the dross with an aqueous ammoniacal solution containing arsenate as the predominant anion under oxidizing conditions to obtain a leachate, removing copper from the leachate to obtain a raffinate and re-cycling raffinate to the leaching stage, and removing a bleed of raffinate from the circuit and precipitating a substantially insoluble arsenic compound from the raffinate bleed to remove arsenic from the circuit.
    Type: Grant
    Filed: December 4, 1981
    Date of Patent: January 18, 1983
    Assignees: Metallurgical Process Limited, I.S.C. Smelting Limited
    Inventor: Hayden Monk
  • Patent number: 4366128
    Abstract: A process for removing arsenic from an aqueous solution containing arsenic in the form of a soluble arsenate includes adjusting the pH of the solution if necessary to at least about 10, adding a soluble barium salt to precipitate arsenic as barium arsenate, and removing the precipitated barium arsenate from the solution.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: December 28, 1982
    Assignee: Sherritt Gordon Mines Limited
    Inventors: Donald R. Weir, Ian M. Masters
  • Patent number: 4244927
    Abstract: An arsenic-recovery process primarily for use in conjunction with the hydrometallurgical processing of arsenic-containing materials for metal recovery. Arsenic is recovered from ferric arsenate by reaction with sodium hydroxide in accordance with the following general reaction:3NaOH+FeAsO.sub.4 .fwdarw.Na.sub.3 AsO.sub.4 +Fe(OH).sub.3During the processing of high arsenic materials such as smelter flue dust, extremely insoluble ferric-arsenic compounds are generated to immobilize the arsenic during leaching of the metals. The arsenic may be recovered in saleable form from the arsenic-containing residues by leaching with sodium hydroxide and crystallizing the arsenic salts from the leach residue.
    Type: Grant
    Filed: July 27, 1979
    Date of Patent: January 13, 1981
    Assignee: Hazen Research, Inc.
    Inventors: James E. Reynolds, Enzo L. Coltrinari
  • Patent number: 4087511
    Abstract: Chemically durable non-silicate glasses derived from compounds including phosphates, borates, arsenates, sulfates, tellurates, tellurites, germanates and the like, are prepared by forming a melt from monobasic compounds of stoichiometric proportions, said melt then being polymerized by suitable means in the melt stage and subsequently cooled to form a desired glass. The resulting glass exhibits properties not normally found in similar glasses prepared from melts of oxides of the same materials.
    Type: Grant
    Filed: March 22, 1977
    Date of Patent: May 2, 1978
    Assignee: Allied Chemical Corporation
    Inventor: Richard C. Ropp
  • Patent number: 4082557
    Abstract: A silver base activating solution, for use prior to electroless copper deposition, contains a salt of a weak oxyacid of an element of group III, IV, V or VI of the periodic system, e.g. sodium tetraborate. A relatively low silver concentration, within the range of 0.01 g/l to 1 g/l can accordingly be used; and the resulting copper coating forms quickly and is compact, smooth and adherent. The silver solution is stable.
    Type: Grant
    Filed: July 19, 1976
    Date of Patent: April 4, 1978
    Assignee: Alfachimici S.p.A.
    Inventor: Pietro Pizzio