Below 300 Degrees C Patents (Class 75/710)
  • Patent number: 5917116
    Abstract: A method of processing a copper mineral, the method comprising activating the copper mineral by milling the copper mineral to P80 of between 2 and 20 micron, and subsequently subjecting the activated copper mineral to an oxidative hydrometallurgical treatment in the presence of chloride ions in an amount of from 2 to 10 g/L.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: June 29, 1999
    Assignee: Dominion Mining Limited
    Inventors: Gary Donald Johnson, Naralia Streltsova
  • Patent number: 5904783
    Abstract: A method for treating a brass fixture having a fluid-contacting surface with lead dispersoids exposed thereon to reduce lead leaching into a fluid supply by contacting the brass fixture with a liquid metal solution selected from the group consisting of a liquid sodium solution, a liquid potassium solution and a liquid metal alloy solution to dissolve lead dispersoids from the fixture, wherein the metal alloy comprises a metal selected from the group consisting of sodium and potassium.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: May 18, 1999
    Assignee: Hazen Research, Inc.
    Inventors: John P. Hager, Jerome P. Downey
  • Patent number: 5885327
    Abstract: Recovery of gold from alkaline cyanide leach solutions using ion exchange adsorbents, comprising (a) contacting the cyanide leach solution containing the gold with an extraction reagent comprised of a solid adsorbent carrying an organic base functionality of a compound having a pK.sub.a between about 9-14, such as a guanidyl functionality, to adsorb gold and eluting the adsorbed gold from the solid adsorbent with an aqueous alkaline eluant solution having a pH above about 12 and containing an alkali metal salt of an aromatic or aliphatic carboxylic acid having from about 4-14 carbon atoms, the eluant solution having incorprated therein from about 0.001 moles to about 0.2 moles per liter of an alkali metal cyanide salt. The solid adsorbent containing the aurocyanide complex may be contacted with a concentrated aqueous solution of a zinc tetracyanide salt whereby the aurocyanide complex is displaced with a zinc tetracyanide complex before treatment with the eluant solution.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: March 23, 1999
    Assignee: Henkel Corporation
    Inventor: Michael J. Virnig
  • Patent number: 5873927
    Abstract: A metal-containing refractory sulfide ore is split into a first portion and a second portion. The first portion is partially biodigested by a sulfide-digesting microorganism in a biooxidation reactor where the microorganism is acclimated to the sulfide "diet" provided by the ore. The partially digested ore is then combined with the second portion. The resulting material is then dewatered, biooxidized and subjected to a lixiviation process.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: February 23, 1999
    Assignees: Echo Bay Mines, Limited, Biomin Technologies SA
    Inventors: Michael R. Schaffner, John D. Batty
  • Patent number: 5829192
    Abstract: Root growth and development of vegetation used to remediate contaminated soil and/or groundwater is directed to targeted zones by a casing lining the hole in which the vegetation is planted. A flexible, self-sealing casing encourages strong and healthy root development of the root system deep in the soil horizons, resulting in an increase in the remedial capacity of the vegetation through the preferential development in or near the zone of soil or groundwater contamination.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: November 3, 1998
    Inventor: Edward G. Gatliff
  • Patent number: 5829191
    Abstract: A method of growing trees for transplantation develops a long and narrow root system for ready rooting activity when transplanted at a remediation site. The trees can be grown in a lined hole with an optional basin, or cap, or otherwise lined at the bottom. The liner can be removed with the root system and associated soils for ease of transportation, and for use in continuing to encourage a downward vertical growth of the root system after transplantation. The trees can also be grown out of the ground in vertical or horizontal tubes which receive, under controlled conditions, water and nutrients. The medium in which tree can be grown out of the ground includes hydroponic media and soil.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: November 3, 1998
    Inventor: Edward G. Gatliff
  • Patent number: 5807421
    Abstract: A hydrometallurgical process for treating copper feed materials containing gold and/or silver by simultaneously leaching copper, gold and/or silver into an aqueous cyanide solution, extracting copper, gold and cyanide with anion exchange resin is provided.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: September 15, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Christopher Andrew Fleming, Walther Gustav Grot, John Anton Thorpe
  • Patent number: 5772730
    Abstract: A method of removing aqueous phase residues and other contaminants from the organic phase used in hydrometallurgical extraction processes comprises passing the organic phase through a column or other vessel in which a porous bed of elements of suitable size and shape to permit flow therethrough is provided. The material making up the bed elements may be polyethylene, polypropylene, nylon, teflon, stainless steel, plastics in general and their derivatives, or combinations thereof. The aqueous phase coalesces on the surfaces of the materials making up the bed and forms droplets which drop to the bottom of the column or vessel which are thereafter removed.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: June 30, 1998
    Assignee: Corporacion Nacional Del Cobre De Chile
    Inventors: Gustavo Holger Bannach Sichtermann, Aliro Teodoro Nelson Pincheira Alvarez, Andres Antonio Reghezza Inzunza, Alberto Segundo Cruz Rivera, Gino Salvador Slanzi Guerra, Ernesto Otmardo Riedel Hohmann, Elias Ahmed Yuri Spataris
  • Patent number: 5769925
    Abstract: A powerful reducing agent such as hydrazine monohydrate is added to the standard eluent solutions such as NsOH-NaCN with or without alcohol. The kinetics of elution of gold or of silver are thus markedly enhanced.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: June 23, 1998
    Assignee: UM Enginerring S.A.
    Inventors: Sarah Harvey, Andre Van Lierde, Pierre Louis
  • Patent number: 5749940
    Abstract: The known method comprises the following steps. (1) the de-copperized anode slime is chlorination-leached with HCl and H.sub.2 O.sub.2. (2) Na.sub.2 CO.sub.3 is added to the chlorination-leach residue of (1). (3) NH.sub.3 is added to the residue of (2). (4) Distillation of NH.sub.3 to remove NH.sub.3 contained in the ammonia leach solution of (3). (5) Distillation residue is washed with water to yield refined AgCl. (6) Conversion of AgCl to Ag.sub.2 O. (7) Reduction of Ag.sub.2 O to Ag. In order to enhance the purity of the reduced silver, the present invention provides the following improvements (a) to (d). (a) Dechlorination (2) with the use of Na.sub.2 CO.sub.3 is carried out at ambient temperature. (b) After dechlorination, the residue is washed with hot water. (c) Sulfuric acid is added instead of carrying out distillation (4). (d) Prior to conversion (6), the chlorination is again carried out.
    Type: Grant
    Filed: March 11, 1997
    Date of Patent: May 12, 1998
    Assignee: Nippon Mining & Metals Co., Inc.
    Inventor: Katutoshi Narita
  • Patent number: 5728197
    Abstract: Tungsten carbide cobalt and tungsten-containing materials are recycled using a single high-temperature oxidation with standard dilution chemistry. The scrap material is ground, oxidized, and subjected to an acid digestion, preferably in hydrochloric acid. This causes the cobalt to form cobalt chloride while the tungsten remains insoluble. The pH is then increased to about 7.0 which causes the cobalt chloride to form cobalt hydroxide which precipitates out of solution. The cobalt and tungsten are separated and dissolved in a high-pH ammonia solution which can then be spray dried to form a precursor powder for subsequent carburization to form tungsten carbide-cobalt powders.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: March 17, 1998
    Assignee: Nanodyne Incorporated
    Inventors: Purnesh Seegopaul, Li Wu
  • Patent number: 5661117
    Abstract: A method of removing contaminated phosphate ester materials is provided. The method involves the use of an anionic resin and a polymeric sorbent. The contaminated phosphate ester material is passed into contact with the anionic resin and optionally the sorbent. The method is particularly useful since it removes substantially all of the contaminants, generally metal material and acids, from the phosphate ester such that the phosphate ester can be reused for further applications.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: August 26, 1997
    Inventor: Peter Dufresne
  • Patent number: 5623725
    Abstract: Process for producing very pure platinum materials dispersion-reinforced with Y.sub.2 O.sub.3 and having high strength and extensibility, even in the temperature range >800.degree. C., from platinum powder by mechanical alloying, which comprises the process stepspreparing platinum powder of high purity and low particle size of from 2 to 10 .mu.m,introducing and dispersing Y.sub.2 O.sub.3 particles >1 .mu.m in the platinum powder by milling in a platinum vessel using milling media of zirconium oxide,degassing the milled product under a vacuum of better than 10.sup.-3 mbar and with an increase in temperature to at least 1200.degree. C. in a platinum capsule for a period of up to 48 hours,gastight welding of the evacuated capsule and hot isostatic pressing at 1350.degree. C.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: April 22, 1997
    Assignee: Schott Glaswerke
    Inventors: Joachim Disam, Gerhard Jangg, Johannes Zbiral, Gerhard Schreier, Christian Edtmaier
  • 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: 5364452
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal, an alkaline earth metal or ammonium chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: November 15, 1994
    Inventors: Domenico C. Cupertino, Peter A. Tasker
  • Patent number: 5364451
    Abstract: A process for removal of metal ions from soil and methods for effecting such removal are described. The process is based on the growth of crop and crop-related members of the plant family Brassicaceae in metal-containing soils. These particular plants will absorb metals into their roots making them not leachable from the soils or will absorb the metal into their roots and transfer them to the shoots which can be easily harvested.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: November 15, 1994
    Assignee: PhytoTech, Inc.
    Inventors: Ilya Raskin, Nanda P. B. A. Kumar, Slavik Douchenkov
  • Patent number: 5356457
    Abstract: A hydrometallurgical process for recovering copper from copper bearing ores or fractions, by a process of first wetting and sulfatizing the ore with controlled amounts of H.sub.2 SO.sub.4 and water, followed by acid curing and repulping to sulfatize a substantial portion of the copper in the ore. Also, the fine and coarse fractions can be classified, followed by pile leaching the coarse fraction, preferably reusing the cycled H.sub.2 SO.sub.4 solution obtained during the copper recovery process. Since the coarse fraction is classified from the fine fraction, the pile leaching process is performed at very high specific flows, which substantially reduces the leaching period as compared with that of conventional pile leaching.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: October 18, 1994
    Assignee: Corporacion Nacional Del Cobre De Chile
    Inventors: Aliro Teodoro Nelson Pincheira Alvarez, Andres Antonio Reghezza Insunza, Alberto Segundo Crus Rivera
  • Patent number: 5352266
    Abstract: A process for producing nanocrystalline materials, and in particular nanocrystalline nickel having an average grain size of less than about 11 nanometers is described. The nanocrystalline material is electrodeposited onto the cathode in an aqueous acidic electrolytic cell by application of a pulsed D.C. current. The cell electrolyte also contains a stress reliever, such as saccharin, which helps to control the grain size. The novel product of the invention find utility as wear resistant coatings, hydrogen storage materials, magnetic materials and as catalysts for hydrogen evolution.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: October 4, 1994
    Assignee: Queen'University at Kingston
    Inventors: Uwe Erb, Abdelmounam M. El-Sherik
  • Patent number: 5332420
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal or alkaline earth metal chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: July 26, 1994
    Assignee: Zeneca Limited
    Inventors: Domenico C. Cupertino, Peter A. Tasker
  • Patent number: 5258167
    Abstract: An extractant for extracting rare earth metal ions comprises, for instance, di-(3-methylcyclohexyl)phosphoric acid, di-1-ethylpentylphosphoric acid, docosyl-(2 isopropyl-5-methylcyclohexyl) phosphoric acid, 2-ethylhexyl-2-methylcyclohexylphosphoric acid and/or 2-hexyloctyl-cyclohexylphosphoric acid or a combination of, for instance, dicyclohexylphosphoric acid and di-(2-heptylundecyl) phosphoric acid. A method for extracting rare earth metals comprises the step of bringing an acidic aqueous solution containing ions of rare earth metals into contact with an extraction medium containing an extractant exemplified above to transfer the rare earth metal ions to the extraction medium. The extractant not only exhibits high extractability for rare earth metal ions but also facilitates the back extraction of the rare earth metal ions therefrom.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: November 2, 1993
    Assignee: Lion Corporation
    Inventors: Toshio Takahashi, Hiroaki Nishizawa, Yukari Ishii
  • Patent number: 5250102
    Abstract: A process for treating optionally oxidized sulphidic material containing one or more heavy metals, by aerobic microbial oxidation of the optionally oxidized sulphidic material in an aqueous suspension using a sulphur oxidizing micro-organism to convert optionally oxidized sulphide into soluble sulphate at a pH sufficient to maintain most of the heavy metals present in a soluble form. A preferred sulphidic material is sulphidic waste, preferably sulphidic slag. The formed sulphate is environmentally less harmful than the sulphide, while the heavy metals compounds are suitable for recovery of the metals using known methods.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: October 5, 1993
    Assignee: Shell Research Limited
    Inventors: Lienel J. Barnes, Andrew B. Suttie
  • Patent number: 5093090
    Abstract: There is disclosed a method for the separation of antimony from acidic solutions which contain antimony, alone, or together with other metallic ions, by extracting antimony with an organic, water-immiscible, polyol-containing diluent. The method comprises the steps of contacting the antimony-containing acidic solution with a water-immiscible organic diluent containing at least one polyol dissolved therein, preferably a diol, said polyol serving to extract the antimony. The polyol serves to selectively extract the antimony from the acidic solution to the exclusion of other metallic ions such as copper and nickel.
    Type: Grant
    Filed: May 4, 1990
    Date of Patent: March 3, 1992
    Assignee: Nuova Samim S.p.A.
    Inventors: Renato Guerriero, Italo Vittadini
  • Patent number: 5019158
    Abstract: A process is disclosed for separating calcium and nitrogen from lithium, in which alumina is added to molten lithium and reacts to produce aluminum and lithium oxide. The aluminum reacts with the nitrogen in the lithium to produce insoluble aluminum nitride, while the lithium oxide reacts with the calcium present to produce insoluble calcium oxide and lithium. The insoluble calcium oxide and aluminum nitride may then be separated from the molten lithium, such as by filtration.
    Type: Grant
    Filed: May 16, 1990
    Date of Patent: May 28, 1991
    Assignee: Metaux Speciaux S.A.
    Inventor: Guy Bernard
  • Patent number: 4976781
    Abstract: Noble metal or diamond values are recovered from ore slurries by contact with pellets of oil, coal and bitumen as a secondary binder. The pellets are of a size above 0.75 mm and contain 2% bitumen and 18% lighter oil fractions. The pellets do not disintegrate and size range remains constant.
    Type: Grant
    Filed: August 21, 1987
    Date of Patent: December 11, 1990
    Assignee: Charlton Mineral Associates Pty. Ltd.
    Inventors: David Mainwaring, Mark Cadzow
  • Patent number: RE36118
    Abstract: A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal or alkaline earth metal chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: March 2, 1999
    Assignee: Zeneca Limited
    Inventors: Domenico C. Cupertino, Peter A. Tasker