Group Vib Metal (cr, Mo, Or W) Patents (Class 423/53)
  • Patent number: 4373070
    Abstract: Novel sequestering agents useful for the extraction of metal values and in various organic syntheses comprise a cross-linked organic polymeric substrate, said substrate having covalently coupled thereto a plurality of functional groups, the free valence of which having the structural formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.6 and R.sub.7, which are identical or different, each represents a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, R.sub.5 and R.sub.8, which are also identical or different, each represents a hydrogen atom, an alkyl or cycloalkyl radical having 1 to 12 carbon atoms, a phenyl radical, a --C.sub.g H.sub.2q --.phi. or C.sub.q H.sub.2+1 --.phi.-- radical, and further wherein q ranges from 1 to about 12, and n, m and p, which are also identical or different, range from 1 to 10, and .phi. is phenyl.
    Type: Grant
    Filed: August 25, 1981
    Date of Patent: February 8, 1983
    Assignee: Rhone-Poulenc Industries
    Inventor: Gerard Soula
  • Patent number: 4355006
    Abstract: A process for the oxidative dissociation of chrome-containing ores comprising agglomerating a mixture of a chrome-containing ore, an alkaline substance and a moist solid residue from a preceding operation as a leaning agent, dissociating the agglomerate and then leaching to form a solution of chromate and a solid residue, and separating said solution from said solid residue still wet with said solution. Advantageously the alkaline substance comprises sodium hydroxide or sodium carbonate, the still wet residue is added in such a quantity that the agglomerates obtained have a moisture content of between about 10 and 15% by weight, and at least about 70% by weight of the agglomerates have a diameter from about 0.1 to 3 mm.
    Type: Grant
    Filed: August 27, 1980
    Date of Patent: October 19, 1982
    Assignee: Bayer Aktiengesellschaft
    Inventors: Jakob Rademachers, Ingo Pflugmacher
  • Patent number: 4353879
    Abstract: Tungsten is recovered from tungsten ore concentrates in the form of sodium tungstate by a basic process in which ground ore is first digested in a sodium hydroxide solution followed by diluting the solution to dissolve sodium tungstate separating the solution from the caustic insoluble sludge and crystallizing soluble sodium tungstate, wherein the present invention permits improved recovery of tungsten from difficult to process ores by the process steps of comminuting said tungsten ore concentrate to a particle size less than about 200 mesh, dispersing the comminuted ore to separate agglomerated particles, adding the dispersed ore to aqueous sodium hydroxide at a concentration of at least 10 molar and digesting at a temperature of from about 75.degree. C. to 150.degree. C. for a sufficient period of time to convert substantially all of the tungsten values to soluble sodium tungstate, and diluting the mixture to reduce the sodium hydroxide concentration to between about 4.5 and 5.
    Type: Grant
    Filed: May 7, 1981
    Date of Patent: October 12, 1982
    Assignee: GTE Products Corporation
    Inventors: Lucretia R. Quatrini, Brice E. Martin
  • Patent number: 4353880
    Abstract: Tungsten is recovered from tungsten ore concentrates in the form of sodium tungstate by a basic process in which ground ore is first digested in a sodium hydroxide solution followed by diluting the solution to dissolve sodium tungstate separating the solution from the caustic insoluble sludge and crystallizing soluble sodium tungstate, wherein the present invention permits improved recovery of tungsten from difficult to process ores by the process steps of drying the insoluble sludge portion, comminuting the dried sludge to a particle size less than about 200 mesh, and dissolving said comminuted sludge in 4.5-5.5 molar NaOH to recover substantially all of the tungsten values.
    Type: Grant
    Filed: May 7, 1981
    Date of Patent: October 12, 1982
    Assignee: GTE Products Corporation
    Inventor: Lucretia R. Quatrini
  • Patent number: 4353878
    Abstract: Tungsten is recovered from tungsten ore concentrates in the form of sodium tungstate by a basic process in which ground ore is first digested in a sodium hydroxide solution followed by diluting the solution to dissolve sodium tungstate separating the solution from the caustic insoluble sludge and crystallizing soluble sodium tungstate, wherein the present invention permits improved recovery of tungsten from difficult to process ores by the process steps of comminuting said tungsten ore concentrate to a particle size less than 325 mesh, adding said comminuted ore to aqueous sodium hydroxide at a concentration of at least 10 molar and digesting at a temperature of from about 75.degree. C. to 150.degree. C. for a sufficient period of time to convert substantially all of the tungsten values to soluble sodium tungstate, and diluting the mixture to reduce the sodium hydroxide concentration to between about 4.5 and 5.5 molar at a temperature below about 90.degree. C.
    Type: Grant
    Filed: May 7, 1981
    Date of Patent: October 12, 1982
    Assignee: GTE Products Corporation
    Inventors: Lucretia R. Quatrini, Marie B. Terlizzi, Brice E. Martin
  • Patent number: 4351808
    Abstract: A process for the soda ash digestion of scheelite concentrates is provided, the process comprising forming a slurry of a scheelite concentrate in an aqueous sodium carbonate solution and then digesting the slurry in an autoclave at an elevated temperature of at least about 180.degree. C. The concentration of the Na.sub.2 CO.sub.3 solution is substantially inversely correlated to the digestion temperature and substantially directly correlated to the Na.sub.2 CO.sub.3 /WO.sub.3 weight ratio such as to effect the selective dissolution of at least about 95% of the WO.sub.3 in the concentrate and provide a pregnant liquor containing WO.sub.3 while inhibiting substantial dissolution of gangue minerals.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: September 28, 1982
    Assignee: Amax Inc.
    Inventors: Leo W. Beckstead, Dale K. Huggins, Paul B. Queneau
  • Patent number: 4348231
    Abstract: Selected portions of metal carbide are recovered from scrap material containing pieces of cemented metal carbide having various compositions of metal carbide distributed in a matrix material. The scrap material is treated with a suitable liquid for a sufficient period of time to dissolve the matrix material and form a piece of matrix depleted metal carbide which is introduced as a feed into a ferrofluid material. A magnetic field is passed through the ferrofluid for positioning pieces of metal carbide of the type having a heavier density spaced from pieces of metal carbide of a lighter density. The separated portions of matrix depleted metal carbide are collected to produce metal carbide powder which may be further reprocessed to produce a desired cemented metal carbide.
    Type: Grant
    Filed: April 17, 1980
    Date of Patent: September 7, 1982
    Assignee: GTE Products Corporation
    Inventors: Joseph E. Ritsko, Martin B. MacInnis, Thomas L. Henson
  • Patent number: 4343774
    Abstract: Cobalt is recovered in substantial amounts from spent catalyst particles comprising cobalt components supported on alumina or other aluminum-containing refractory oxides. The process comprises contacting the catalyst with sulfuric acid, then subjecting the catalyst to oxidation in an oxygen-containing atmosphere under conditions of elevated temperature, and again contacting the catalyst with sulfuric acid to extract cobalt. Molybdenum, if present on the catalyst, is recovered with the cobalt, as are other metals, such as nickel and tungsten.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: August 10, 1982
    Assignee: Union Oil Company of California
    Inventor: George L. Tilley
  • Patent number: 4342728
    Abstract: Oxide ores or ore concentrates containing organic matter are slurried with water and heated to a temperature of at least about 230.degree. C. under an oxygen partial pressure of at least about 25 psi to oxidize the organic matter. Advantageously, the process in accordance with the present invention can be used in the treatment of tungsten concentrates and can be employed while the tungsten concentrates are being digested with sodium carbonate or sodium hydroxide solutions.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: August 3, 1982
    Assignee: AMAX Inc.
    Inventors: Paul B. Queneau, Leo W. Beckstead, Robert F. Hogsett
  • Patent number: 4340571
    Abstract: This disclosure is concerned with a tannery primary treatment process that, in total combination, or as separate sub-process features, enables the reducing of BOD loading in such treatment, while increasing the efficiency of hexavalent chrome recovery therefrom by separating out alkaline sulfide solids from the normal unhairing beamhouse stage and utilizing the same to attain appropriate sedimentation tank sludge pH for oxidation of the chrome to the hexavalent state during incineration; and/or increasing the hexavalent chrome recovery by backwetting and roasting the ash again; and/or enabling use of such ash for recycling as a chrome tanning liquor with the side-production of an improved flocculating chrome water wash for waste treatment use.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: July 20, 1982
    Assignee: Saco Tanning Division of Kirstein Leather Co.
    Inventor: James E. Cartier
  • Patent number: 4338287
    Abstract: A process for conditioning a tungsten concentrate containing tungsten as WO.sub.3, sulfur as sulfide, and calcite to fix at least a portion of the sulfur as calcium sulfate by reaction with the calcite, comprises providing a tungsten concentrate having a calcite content such that less than about 15 wt. % calcium sulfate based on the weight of the WO.sub.3 in the concentrate will be formed and heating the concentrate to a temperature of at least about 500.degree. C. in an oxidizing atmosphere to oxidize substantially all the sulfur in the concentrate to provide a conditioned concentrate having a calcium sulfate content less than about 15% based on the weight of the WO.sub.3, whereby the conditioned concentrate can be efficiently leached with alkali metal carbonates or hydroxides and the resulting alkali metal tungstate solution can be effectively treated to recover an ammonium tungstate solution.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: July 6, 1982
    Assignee: Amax Inc.
    Inventors: Robert F. Hogsett, Dale K. Huggins, Leo W. Beckstead
  • Patent number: 4337227
    Abstract: Chromium is selectively precipitated from waste solutions by means of benzoate ion. The resulting chromium benzoate complex is separated, washed and treated with either base or sulfuric acid to recover the benzoate and a chromium hydroxide product.
    Type: Grant
    Filed: September 10, 1981
    Date of Patent: June 29, 1982
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventors: Hector O. McDonald, Lawrence C. George
  • Patent number: 4332584
    Abstract: A method of recovering chromium values and potential energy from liquid and solid leather tannery wastes comprising pyrolyzing the tannery wastes to produce a burnable fuel product comprising gases and liquids and a substantially solid chromium-containing residue, recovering chromium compounds from the solid residue and using the fuel to supply energy for the system.
    Type: Grant
    Filed: February 3, 1981
    Date of Patent: June 1, 1982
    Assignee: Systems Consultants, Inc.
    Inventor: H. S. Muralidhara
  • Patent number: 4328191
    Abstract: A method of recovering molybdenum from the catalyst residue derived from the process of epoxidizing olefins is disclosed. The catalyst residue, in semi-solid form or as a solution diluted in an organic solvent, is contacted with an aqueous solution of an oxidizing agent such as hydrogen peroxide, nitric acid, or sodium hypochlorite to transfer the molybdenum to the aqueous solution. The molybdenum is thereafter isolated directly from the aqueous solution or, alternatively, from the aqueous solution following preconcentration by liquid-liquid or liquid-solid extraction.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: May 4, 1982
    Assignee: GTE Laboratories Incorporated
    Inventors: Sophia R. Su, Samuel Natansohn
  • Patent number: 4325919
    Abstract: A continuous process with feedback control is disclosed for the soda ash digestion of tungsten concentrates in which a slurry of the concentrate in an aqueous sodium carbonate solution is digested in an autoclave at a temperature of at least about 180.degree. C. to provide a pregnant solution of WO.sub.3. High dissolution efficiency is maintained during digestion by continuously monitoring the pregnant solution which includes determining the specific gravity and the Na.sub.2 CO.sub.3 concentration of the pregnant liquor from which feedback signals are produced which are used to control the amount of Na.sub.2 CO.sub.3 and H.sub.2 O fed to the slurry in accordance with the digestion conditions predetermined to provide the desired dissolution efficiency.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: April 20, 1982
    Assignee: AMAX Inc.
    Inventors: Paul B. Queneau, Leo W. Beckstead, Dale K. Huggins
  • Patent number: 4321089
    Abstract: A process for the recovery of molybdenum and rhenium from their sulfide ores which comprises subjecting the ores to microwave energy in the presence of oxygen to selectively heat the sulfides to convert them to oxides, and recovering the formed oxides. Alternatively, the sulfides in the ore are selectively heated with microwave energy in the presence of chlorine to convert them to the corresponding chlorides, and the metals recovered from the chlorides.
    Type: Grant
    Filed: June 11, 1980
    Date of Patent: March 23, 1982
    Assignee: Cato Research Corporation
    Inventors: Paul R. Kruesi, Veryl H. Frahm, Jr.
  • Patent number: 4320094
    Abstract: Alloy scrap containing refractory metals such as chromium, molybdenum, tungsten, vanadium, niobium and tantalum and base metals such as nickel, cobalt, copper and iron are treated to partition the refractory metal values from the base metal values without an energy intensive remelting step. The scrap in finely divided form is calcined in the presence of an oxygen containing gas and a member of a certain group of alkali metal salts at a temperature in the range of 800.degree. C. to 1150.degree. C. for 1/4 hour to four hours. This treatment converts the refractory metals to alkali metal molybdates, tungstates, chromates, vanadates, niobates and tantalates and the base metals to oxides. The calcined product may then be water leached to produce a substantially base metal-free liquor rich in refractory metal values. Both the refractory and the base metal values may be subsequently recovered by conventional hydrometallurgical techniques.
    Type: Grant
    Filed: April 15, 1980
    Date of Patent: March 16, 1982
    Assignee: Cabot Corporation
    Inventors: Jameel Menashi, Alkis S. Rappas, Donald A. Douglas
  • Patent number: 4320095
    Abstract: A process for the soda ash digestion of refractory tungsten concentrates is provided, the process comprising forming a slurry of the concentrate in an aqueous solution to which sodium carbonate is added in stages while digesting the slurry in an autoclave at a selected elevated temperature of at least about 180.degree. C. to control the concentration of the sodium carbonate during digestion to provide high extraction yields of the contained WO.sub.3. The total amount of the Na.sub.2 CO.sub.3 added stage-wise to complete the digestion is substantially inversely correlated to the digestion temperature and substantially directly correlated to the Na.sub.2 CO.sub.3 /WO.sub.3 weight ratio such as to effect dissolution of at least about 97%, and generally at least about 98%, of the WO.sub.3 in the concentrate and provide a pregnant liquor containing WO.sub.3, the stage-wise addition of the sodium carbonate being such as to inhibit the dissolution of gangue minerals, such as silica, contained in the concentrate.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: March 16, 1982
    Assignee: Amax Inc.
    Inventors: Paul B. Queneau, Dale K. Huggins, Leo W. Beckstead
  • Patent number: 4320096
    Abstract: A process for the soda digestion of mixed wolframite and scheelite concentrates is provided, the process comprising forming a slurry of the mixed wolframite and scheelite concentrates in an aqueous sodium carbonate solution and then digesting the slurry in an autoclave at a temperature of at least about 180.degree. C. During digestion a predetermined amount of sodium hydroxide is added calculated stoichiometrically to react with NaHCO.sub.3 formed as a result of the hydrolysis of FeCO.sub.3 or FeCO.sub.3 and MnCO.sub.3 produced during the digestion of the wolframite and convert it to Na.sub.2 CO.sub.3. The concentration of the Na.sub.2 CO.sub.3 solution is substantially inversely correlated to the digestion temperature and substantially directly correlated to the Na.sub.2 CO.sub.3 /WO.sub.3 weight ratio ranging from about 0.9 to 2 such as to effect dissolution of at least about 95% of the WO.sub.3 in the concentrate and provide a pregnant liquor containing said WO.sub.3.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: March 16, 1982
    Assignee: Amax Inc.
    Inventors: Paul B. Queneau, Dale K. Huggins, Leo W. Beckstead
  • Patent number: 4318788
    Abstract: A process for recovering and recycling chromium from chromium-iron hydroxide sludge for use in cooling tower make up water and plating solution is disclosed. The process comprises separating chromium from the sludge by selectively oxidizing the trivalent chromium precipitate to soluble hexavalent chromium with a strong oxidizing agent such as chlorine gas, in alkaline medium. The hexavalent chromium ions then enter solution and are thereafter separated from the iron hydroxide precipitate as the sludge is dewatered.
    Type: Grant
    Filed: December 12, 1979
    Date of Patent: March 9, 1982
    Assignee: ANDCO Environmental Processes, Inc.
    Inventor: Joseph G. Duffey
  • Patent number: 4317802
    Abstract: The process relates to the separation of the molybdenum and/or tungsten, titanium, vanadium, niobium or tantalum present in the form of organometallic compounds in residual effluents.It is applicable, in particular, to the effluents originating from the epoxidation of olefins by hydroperoxides.The process involves treating the effluent with from 1 to 10% by weight of water, at between 150.degree. and 220.degree. C. under pressure, to render the metals listed above insoluble, without forming a distinct aqueous phase. The solid phase containing more than 95% of the metals is separated by filtration. After treatment, the effluents can be used without disadvantage, for example as a fuel, and the metals can be recovered from the solid phase.
    Type: Grant
    Filed: November 5, 1980
    Date of Patent: March 2, 1982
    Assignee: Metaux Speciaux
    Inventor: Jacques Dugua
  • Patent number: 4315896
    Abstract: The process of separating components of a crude reaction mixture obtained from a molybdenum-catalyzed hydroperoxide epoxidation of an olefin wherein the product epoxide and an alcohol corresponding to the hydroperoxide used are removed from the reaction mixture leaving a spent catalyst solution and subjecting the spent catalyst solution to a liquid-to-liquid solvent extraction to separate dissolved molybdenum values is improved by solvent extracting the spent catalyst solution with an extracting medium consisting essentially of water and a water immiscible organic solvent to form a two phase system and then separating the molybdenum-rich aqueous phase extract from the organic phase extract. The molybdenum-rich aqueous phase extract may be treated to recover the molybdenum as a solid or the extract may be treated to obtain an active molybdenum catalyst suitable for reuse as a catalyst in a hydroperoxide epoxidation reation.
    Type: Grant
    Filed: January 21, 1981
    Date of Patent: February 16, 1982
    Assignee: Atlantic Richfield Company
    Inventors: Paul D. Taylor, Michael T. Mocella
  • Patent number: 4313914
    Abstract: A calcium tungstate concentrate is produced by slurrying an aqueous sodium tungstate liquor with calcium carbonate at about 130.degree. C. to about 200.degree. C. while providing sufficient carbon dioxide overpressure to convert sodium carbonate in the slurry to sodium bicarbonate, wherein the conversion of sodium tungstate to solid calcium tungstate in the slurry is promoted. The carbon dioxide is then stripped from the slurry, causing the sodium bicarbonate to convert to sodium carbonate, and a calcium tungstate concentrate is filtered from the slurry. The invention is useful in upgrading impure calcium tungstate concentrates.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: February 2, 1982
    Assignee: Amax Inc.
    Inventors: Dale K. Huggins, Paul B. Queneau, Leo W. Beckstead
  • Patent number: 4311679
    Abstract: Basic sodium tungstate leach liquor is treated to reduce the concentration dissolved therein of silica, phosphorus and fluorine impurities in a process which comprises providing a small but effective amount of magnesium in the liquor to maximize removal of silica and phosphorus from solution in the liquor while maintaining the liquor temperature between about 60.degree. C. and about 100.degree. C. and the liquor pH between about 9 and about 11, filtering the liquor, adjusting the liquor pH to between about 6 and about 8 and the liquor temperature to between about 20.degree. C. and about 60.degree. C., and then providing a small but effective amount of aluminum hydroxide in the filtered liquor to maximize removal of fluorine from solution in the liquor while maintaining the liquor temperature between about 20.degree. C. and about 60.degree. C. and the liquor pH between about 6 and about 8.
    Type: Grant
    Filed: January 19, 1981
    Date of Patent: January 19, 1982
    Assignee: Amax Inc.
    Inventors: Paul B. Queneau, Leo W. Beckstead, Dale K. Huggins
  • Patent number: 4298581
    Abstract: Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel, iron, and copper. The scrap is calcined with sodium carbonate in air to convert the refractory metal values to MoO.sub.4.sup.=, VO.sub.4.sup..ident., WO.sub.4.sup.=, and CrO.sub.4.sup.= and the base metals to water insoluble oxides. A leach of the calcined materials produces a pregnant liquor rich in refractory metals which, after separation of the vanadium, molybdenum and tungsten values, is treated with CO, CHOO.sup.- CH.sub.3 OH, or HCHO to reduce Cr.sup.+6 to CR.sup.+3. The carbonate and bicarbonate salts produced as a byproduct of the reduction are recycled to the calcination stage.As a result of the V, W, and Mo partition, a mixed solid comprising CaO.nV.sub.2 O.sub.5, CaMoO.sub.4, and CaWO.sub.4 is produced.
    Type: Grant
    Filed: April 15, 1980
    Date of Patent: November 3, 1981
    Assignee: Cabot Corporation
    Inventors: Donald A. Douglas, Jameel Menashi, Alkis S. Rappas
  • Patent number: 4298582
    Abstract: Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel, iron, and copper. The scrap is calcined with sodium carbonate in air to convert the refractory metal values to MoO.sub.4.sup.=, VO.sub.4.sup..ident., WO.sub.4.sup.=, and CrO.sub.4.sup.= and the base metals to water insoluble oxides. A leach of the calcined materials produces a pregnant liquor rich in refractory metals which, after separation of the vanadium, molybdenum and tungsten values, is treated with CO, CHOO.sup.-, CH.sub.3 OH, or HCHO to reduce Cr.sup.+6 to Cr.sup.+3. The carbonate and bicarbonate salts produced as a byproduct of the reduction are recycled to the calcination stage.As a result of the V, W, and Mo partition, a mixed solid comprising CaO.nV.sub.2 O.sub.5, CaMoO.sub.4, and CaWO.sub.4 is produced.
    Type: Grant
    Filed: April 15, 1980
    Date of Patent: November 3, 1981
    Assignee: Cabot Corporation
    Inventors: Jameel Menashi, Alkis S. Rappas, Donald A. Douglas
  • Patent number: 4296077
    Abstract: A process for the recovery of molybdenum values from leach muds of molybdenite concentrates which have been roasted in air to convert molybdenum sulfide to molybdenum trioxide and subsequently leached with an aqueous alkaline solution for the recovery of soluble molybdenum salts. Leach mud is treated by the process of this invention by repulping the leach mud with aqueous ammonium hydroxide under pressure, at a temperature in the range of about 50 to 150.degree. C. for a period of 2 or more hours after which undissolved solid material is separated from the ammoniacal leach solution and repulped with an aqueous caustic leach solution at a temperature in the range of 50.degree. to 150.degree. C. for a period of 2 to 4 hours. Undissolved solid material is separated from the caustic leach solution and both the ammoniacal and the caustic leach solutions processed for the recovery of molybdenum salts therefrom.
    Type: Grant
    Filed: November 10, 1980
    Date of Patent: October 20, 1981
    Assignee: Engelhard Min. & Chem. Corp.
    Inventors: Steven R. Heuer, Zdenka Zbranek
  • Patent number: 4296076
    Abstract: Chromic oxide of very low (below 40 ppm) insoluble sulphur content is obtained by calcination of a less pure product at a temperature above 1100.degree. C. for at least 10 minutes.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: October 20, 1981
    Assignee: British Chrome & Chemicals Ltd.
    Inventors: Danvers A. Swales, Michael A. Marshall
  • Patent number: 4293334
    Abstract: A process for the recovery of valuable metals or their compounds from an aqueous medium, such as a metals refinery process waste solution. Metals are recovered in water-insoluble form from aqueous solutions of metal salts by contacting the aqueous solution with a killed fungus of the type commonly called molds for a period of time sufficient to convert soluble metal components in the aqueous solution to a water insoluble form sequestered by the dead fungus. After treatment, metals-containing fungus is separated from the treated aqueous medium and processed for the recovery of metal values.
    Type: Grant
    Filed: February 12, 1980
    Date of Patent: October 6, 1981
    Assignee: Engelhard Minerals & Chemicals Corporation
    Inventors: Walter Drobot, Hubert A. Lechavelier
  • Patent number: 4291000
    Abstract: Chromium trioxide contaminated with sulphate is purified by washing with an aqueous purifying wash liquor, generally water or aqueous chromic acid, while at a temperature above 50.degree. C. and centrifuging the washed product. Washing is generally conducted on the centrifuge. The chromium trioxide is preferably made by reacting sodium dichromate with from 2.4 to 2.8 mols sulphuric acid. The process can be operated to produce a novel product consisting of crystalline, non-fused, chromium trioxide that is substantially pure. The novel product can be in the form of pellets.
    Type: Grant
    Filed: February 11, 1980
    Date of Patent: September 22, 1981
    Assignee: British Chrome & Chemicals Limited
    Inventors: Danvers A. Swales, Michael A. Marshall
  • Patent number: 4283257
    Abstract: In a process for producing ammonium metatungstate from ammonium paratungstate, ammonium paratungstate is introduced in the anode chamber of an electrolytic cell which is separated from the cathode chamber by an inert liquid permeable media, when a direct electric current is passed through the cell, ammonium ions migrate to the cathode compartment resulting in an increased concentration of metatungstate in the anode chamber.
    Type: Grant
    Filed: June 9, 1980
    Date of Patent: August 11, 1981
    Assignee: GTE Products Corporation
    Inventors: Clarence D. Vanderpool, Martin B. MacInnis
  • Patent number: 4278644
    Abstract: Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel, iron, and copper. The scrap is calcined with sodium carbonate in air to convert the refractory metal values to MoO.sub.4.sup..dbd., VO.sub.4.sup..tbd., WO.sub.4.sup..dbd., and CrO.sub.4.sup..dbd. and the base metals to water insoluble oxides. A leach of the calcined materials produces a pregnant liquor rich in refractory metals which, after separation of the vanadium, molybdenum and tungsten values, is treated with CO, CHOO.sup.-, CH.sub.3 OH, or HCHO to reduce Cr.sup.+6 to Cr.sup.+3. The carbonate and bicarbonate salts produced as a byproduct of the reduction are recycled to the calcination stage.As a result of the V, W, and Mo partition, a mixed solid comprising CaO.nV.sub.2 O.sub.5, CaMoO.sub.4, and CaWO.sub.4 is produced.
    Type: Grant
    Filed: April 15, 1980
    Date of Patent: July 14, 1981
    Assignee: Cabot Corporation
    Inventors: Alkis S. Rappas, Jameel Menashi, Donald A. Douglas
  • Patent number: 4259296
    Abstract: To recover chromium from scrap such as superalloy scrap, the feedstock is melted, subjected to controlled oxidation to oxidize and slag off reactive metals, then subjected to sulfidation and slow cooling to produce a coarse-grained solid wherein the bulk of the chromium is present in a phase consisting predominantly of a chromium sulfide.
    Type: Grant
    Filed: December 27, 1979
    Date of Patent: March 31, 1981
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventors: Francis J. Hennion, John J. deBarbadillo, Umar M. U. Ahmad
  • Patent number: 4256703
    Abstract: To a coal-fired furnace that uses electrostatic precipitation or a mechanical collector to collect fly ash, a mix of magnesia-alumina or magnesia-talc is added above the fireball (2600.degree.-3300.degree. F.). The additive increases the mean particle size of the fly ash and reduces its surface resistivity, thereby causing improved collection in the electrostatic precipitators or mechanical collector. Fine particulates containing heavy metals tend to be agglomerated; thus the invention permits recovery of substantial amounts of heavy metal contaminants that would otherwise be lost as stack emission.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: March 17, 1981
    Assignee: Chemed Corporation
    Inventors: Shyam N. S. Dixit, Douglas I. Bain, David A. Carter
  • Patent number: 4256496
    Abstract: Metals in oxide, carbonate and/or hydroxide form in ores or ore concentrates are converted to the corresponding carbide by a solid state reaction with carbon. The carbide then is separated in substantially pure form from the gangue constituents and may be converted to the metal.
    Type: Grant
    Filed: November 9, 1978
    Date of Patent: March 17, 1981
    Assignee: Ontario Research Foundation
    Inventor: Hans G. Brandstatter
  • Patent number: 4256708
    Abstract: In a process for recovering tungsten from cemented tungsten carbide, the cemented tungsten carbide is oxidized to form an oxidized product which is digested in an aqueous solution of an alkali metal hydroxide to form a water soluble alkali metal tungstate portion and an insoluble portion. The improvement of the present invention provides for recovery of tungsten values from the above mentioned insoluble portion by digesting the insoluble portion in an aqueous alkali metal hydroxide solution with a suitable amount of titanium oxide to promote the formation of a soluble alkali metal tungstate.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: March 17, 1981
    Assignee: GTE Products Corporation
    Inventor: Lucretia R. Quatrini
  • Patent number: 4255397
    Abstract: In a process for recovering tungsten from cemented tungsten carbide, the tungsten carbide is oxidized to form an oxidized product and the oxidized product is digested in an aqueous solution of alkali metal hydroxide to form a soluble portion containing tungsten values and an insoluble residue portion. According to the improved process of the present invention, tungsten values are recovered from the insoluble residue portion by mixing the insoluble portion with an alkali metal carbonate to form a resulting mixture, roasting the resulting mixture in an atmosphere containing oxygen to oxidize the insoluble portion and form another product which is leached with water to recover soluble tungsten values.
    Type: Grant
    Filed: December 21, 1979
    Date of Patent: March 10, 1981
    Assignee: GTE Products Corporation
    Inventors: Brice E. Martin, Joseph E. Ritsko, Howard L. Acla
  • Patent number: 4243553
    Abstract: High surface area molybdenum disulfide, MoS.sub.2, is produced by the thermal decomposition of selected substituted ammonium thiomolybdate salts at temperatures of about 300.degree.-800.degree. C., with said salts being heated to decomposition temperature slowly, in an essentially oxygen-free atmosphere, through the temperature interval in which the substantial portion of the particular substituted ammonium thiomolybdate salts decompose. The product molybdenum disulfide has superior catalytic properties for the water gas shift and methanation reactions compared with conventional MoS.sub.2. The stability of the catalyst is enhanced by decomposing the thiomolybdate salt in admixture with an inert, preformed particulate diluent or by bulk doping said salt with tungsten or vanadium prior to decomposition of the salt. The molybdenum disulfide of the invention also has desirable properties for use in catalyzed hydrogenation and hydrotreating reactions, i.e.
    Type: Grant
    Filed: June 11, 1979
    Date of Patent: January 6, 1981
    Assignee: Union Carbide Corporation
    Inventors: Alfred W. Naumann, Albert S. Behan
  • Patent number: 4243554
    Abstract: High surface area molybdenum disulfide, MoS.sub.2, is produced by the thermal decomposition of selected ammonium thiomolybdate salts at temperatures of about 300.degree.-800.degree. C., with said salts being heated to decomposition temperature at a rate in excess of about 15.degree. C./min., e.g., about 20.degree.-30.degree. C./min., in an essentially oxygen-free atmosphere. The product molybdenum disulfide has superior catalytic properties for the water gas shift and methanation reactions compared with conventional MoS.sub.2. The stability of the catalyst is enhanced by decomposing the thiomolybdate salt in admixture with an inert, preformed particulate diluent or by bulk doping said salt with tungsten or vanadium prior to decomposition of the salt. The molybdenum disulfide of the invention also has desirable properties for use in catalyzed hydrogenation and hydrotreating reactions, i.e., hydrodenitrogenation and hydrodesulfurization reactions, particularly when employed in nickel or cobalt-promoted form.
    Type: Grant
    Filed: June 11, 1979
    Date of Patent: January 6, 1981
    Assignee: Union Carbide Corporation
    Inventors: Alfred W. Naumann, Albert S. Behan
  • Patent number: 4236918
    Abstract: Process for recovery of copper, molybdenum, gold and elemental sulfur in tailings from hydrometallurgical processing of copper sulfide ores, particularly chalcopyrite. The tailings are usually discarded, and thus the recovery of valuable elements therefrom makes the environmentally desirable hydrometallurgical processes of FIG. 1 economically feasible.The tailings are concentrated to a small bulk volume by froth flotation to reject barren gangue and the process (FIG.
    Type: Grant
    Filed: January 15, 1979
    Date of Patent: December 2, 1980
    Assignee: Cyprus Metallurgical Processes Corporation
    Inventor: Kartik A. Narain
  • Patent number: 4237101
    Abstract: Solid carbonaceous fossil fuels such as coal, lignite and peat are treated with an aqueous medium containing a novel catalyst to remove undesirable constituents and produce valuable products. The catalyst is prepared by steps including admixing a water soluble alkali metal silicate with an aqueous medium containing carefully controlled amounts of dissolved water soluble substances which are sources of calcium ion and magnesium ion, reacting the same to produce an aqueous colloidal suspension of the reaction product, admixing a micelle-forming surfactant with the aqueous medium, and agitating the aqueous medium containing the colloidal particles and surfactant to form catalyst-containing micelles. In one variant, particles of a fossil fuel containing metal values are treated with an aqueous medium in the presence of the catalyst, and thereafter the treated particles are separated from the aqueous medium and extracted with an aqueous leach solution in which the metal values are soluble.
    Type: Grant
    Filed: April 14, 1978
    Date of Patent: December 2, 1980
    Assignee: CAW Industries, Inc.
    Inventor: John W. Willard, Sr.
  • Patent number: 4229399
    Abstract: A process is provided wherein solid mixtures of metal chlorides of, for example, ferric chloride, ferrous chloride, vanadium chloride and chromium chloride are (1) mixed with an alkaline material such as, for example, calcium oxide, calcium hydroxide and calcium carbonate, followed (2) by adding water to the resulting mixture to granulate said mixture whereby the metal chlorides are rendered substantially insoluble in water.
    Type: Grant
    Filed: August 10, 1978
    Date of Patent: October 21, 1980
    Assignee: NL Industries, Inc.
    Inventors: Donald G. Cole, Achim Hartmann, Achim M. Kulling, Hermann B. Trub
  • Patent number: 4215989
    Abstract: This disclosure is concerned with a tannery primary treatment process that, in total combination, or as separate sub-process features, enables the reducing of BOD loading in such treatment, while increasing the efficiency of hexavalent chrome recovery therefrom by separating out alkaline sulfide solids from the normal unhairing beamhouse stage and utilizing the same to attain appropriate sedimentation tank sludge pH for oxidation of the chrome to the hexavalent state during incineration; and/or increasing the hexavalent chrome recovery by backwetting and roasting the ash again; and/or enabling use of such ash for recycling as a chrome tanning liquor with the side-production of an improved flocculating chrome water wash for waste treatment use.
    Type: Grant
    Filed: June 19, 1978
    Date of Patent: August 5, 1980
    Assignee: Saco Tanning Division of Kirstein Leather Co.
    Inventor: James E. Cartier
  • Patent number: 4213942
    Abstract: A flotation process for concentrating tungsten or tin ores is achieved by grinding the ores with a grinding medium other than steel, first conditioning a deslimed sulfide free pulp with an acid, further treating the pulp with an emulsified collector and recovering the tungsten or tin in the float. The flotation concentrate can be further enriched by leaching with an inorganic acid.
    Type: Grant
    Filed: January 23, 1978
    Date of Patent: July 22, 1980
    Assignee: Groupe Minier Sullivan Ltee/Sullivan Mining Group Ltd.
    Inventor: Edward W. J. Thornton
  • Patent number: 4207295
    Abstract: Method for the recovery of chrome hydrate or high purity Cr.sub.2 O.sub.3 from chromium ores by roasting the ore with Na.sub.2 CO.sub.3 and CaO, water leaching the roasted mass, precipitating aluminum impurities from the leach liquor as Al(OH).sub.3 and contacting the leach liquor with sulfur and NaOH in order to reduce the chromium values in the leach liquor from valence 6 to 3 to provide a chrome hydrate precipitate. The chrome hydrate precipitate is acid repulped to provide a chrome hydrate from which sodium impurities have been removed. The chrome hydrate is dried and the resulting solids are calcined to provide a high purity Cr.sub.2 O.sub.3.
    Type: Grant
    Filed: February 13, 1979
    Date of Patent: June 10, 1980
    Assignee: Union Carbide Corporation
    Inventors: Tadashi J. Kagetsu, William B. De Atley, Joseph S. Fox
  • Patent number: 4192851
    Abstract: The process of the invention is for the separate recovery of elemental sulfur and residual sulfides and metal salt solution from reaction slurries obtained from leaching of metal sulfides in ores and concentrates.
    Type: Grant
    Filed: March 14, 1978
    Date of Patent: March 11, 1980
    Assignee: Sherritt Gordon Mines Limited
    Inventors: Horst E. Hirsch, John F. Higginson, Ernest G. Parker, Godefridus M. Swinkels
  • Patent number: 4189461
    Abstract: Sulfidic minerals containing metal values such as copper, silver, nickel, cobalt, molybdenum, zinc, iron, or mixtures thereof are leached in two stages. In the second stage, preleached minerals are oxidized with nitrogen dioxide to enable the metal values to be solubilized in the aqueous acidic leach liquor in that stage. During the reaction, the nitrogen dioxide is reduced to nitric oxide. The nitric oxide is oxidized to nitrogen dioxide by oxygen. The acidic metal bearing liquor from the second stage flows to a first stage where it preleaches fresh minerals. The metal bearing liquor is delivered from the first stage to metal recovery while preleached minerals are delivered to the second stage.
    Type: Grant
    Filed: February 23, 1978
    Date of Patent: February 19, 1980
    Assignee: Kennecott Copper Corporation
    Inventors: Robert E. Lueders, Theodore C. Frankiewicz
  • Patent number: 4168296
    Abstract: A process for recovering tungsten from tungsten bearing ores comprises producing a concentrate from the ore and leaching the concentrate at atmospheric pressure in a strong mineral acid solution, for example, a solution of sulfuric acid, hydrochloric acid or nitric acid within a temperature range of from 40.degree. to 90 Centigrade for from one to four hours in the presence of an inorganic complexing agent, and adding an ammonium salt compound for precipitating the tungsten. The precipitate is then dissolved in Ammonium Hydroxide and the tungsten recovered as Ammonium Paratungstate.
    Type: Grant
    Filed: February 17, 1978
    Date of Patent: September 18, 1979
    Inventor: Adolph Q. Lundquist
  • Patent number: 4167555
    Abstract: Tungsten is extracted from hot springs tungsten ores by means of a process comprising (1) calcining the ore, (2) quenching the calcined ore in aqueous alkaline solution and (3) treating the resulting slurry at elevated temperature and pressure to extract the tungsten values from the ore.
    Type: Grant
    Filed: December 15, 1978
    Date of Patent: September 11, 1979
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventors: John M. Gomes, Daniel A. O'Keefe, Andrea E. Raddatz
  • Patent number: 4165362
    Abstract: An improved process is described for the hydrometallurgical liquid phase oxidation of molybdenum disulfide ore concentrates, in which the reactants include in the range of from about 0.12 to about 1.68 mols of an alkali metal hydroxide, preferably sodium hydroxide, per mol of molybdenite, and the time of the reaction, the amount of the alkali metal hydroxide, and the reaction temperature and pressure are coordinated to achieve at least a 95% oxidation conversion of the molybdenum disulfide.
    Type: Grant
    Filed: April 13, 1978
    Date of Patent: August 21, 1979
    Assignee: Engelhard Minerals & Chemicals Corporation
    Inventor: Victor R. Reynolds