Patents by Inventor David A. Neudorf

David A. Neudorf has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7416711
    Abstract: An atmospheric leach process in the recovery of nickel and cobalt from lateritic ores, said processing including the steps of: a) separating the lateritic ore into a low magnesium containing ore fraction, and a high magnesium containing ore fraction by selective mining or post mining classification; b) separately slurrying the separated ore fractions; c) leaching the low magnesium containing ore fraction with concentrated sulphuric acid as a primary leach step; and d) introducing the high magnesium content ore slurry following substantial completion of the primary leach step and precipitating iron as goethite or another low sulphate containing form of iron oxide or iron hydroxide, wherein sulphuric acid released during iron precipitation is used to leach the high magnesium ore fraction as a secondary leach step.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: August 26, 2008
    Assignee: QNI Technology Pty. Ltd.
    Inventors: Houyuan Liu, James D. Gillaspie, Coralie Adele Lewis, David Neudorf, Steven Barnett
  • Publication number: 20060024224
    Abstract: A process for leaching laterite ores containing limonite and saprolite. Sufficient mineral acid is added to a slurry of limonite which is leached at atmospheric pressure to dissolve most of the soluble non-ferrous metals and soluble iron. After adding saprolite the slurry is further leached at a temperature above the normal boiling point and at a pressure above atmospheric pressure for a time sufficient to leach most of the contained nickel in the saprolite and to precipitate most of the iron in solution. The pressure of the slurry is then reduced, and nickel and/or cobalt is subsequently recovered from the leach solution by solvent extraction, resin-in-pulp or other ion exchange, sulfide or hydroxide precipitation, or other recovery method.
    Type: Application
    Filed: June 24, 2005
    Publication date: February 2, 2006
    Inventors: David Neudorf, David Huggins
  • Publication number: 20060002835
    Abstract: A process for leaching laterite ores containing limonite and saprolite in a two stage process. The first stage consisting of mixing and reacting the ore with concentrated mineral acid, and the second stage consisting of preparing a slurry of the acid/ore mixture in water and leaching the mixture to dissolve nickel and cobalt. Iron is efficiently separated from nickel and cobalt in the solid leach residue primarily as an oxide or hydroxide of ferric iron other than jarosite.
    Type: Application
    Filed: June 27, 2005
    Publication date: January 5, 2006
    Inventor: David Neudorf
  • Publication number: 20050226797
    Abstract: An atmospheric leach process in the recovery of nickel and cobalt from lateritic ores, said processing including the steps of: a) separating the lateritic ore into a low magnesium containing ore fraction, and a high magnesium containing ore fraction by selective mining or post mining classification; b) separately slurrying the separated ore fractions; c) leaching the low magnesium containing ore fraction with concentrated sulphuric acid as a primary leach step; and d) introducing the high magnesium content ore slurry following substantial completion of the primary leach step and precipitating iron as goethite or another low sulphate containing form of iron oxide or iron hydroxide, wherein sulphuric acid released during iron precipitation is used to leach the high magnesium ore fraction as a secondary leach step.
    Type: Application
    Filed: March 14, 2003
    Publication date: October 13, 2005
    Inventors: Houyuan Liu, James Gillaspie, Coralie Lewis, David Neudorf, Steven Barnett
  • Patent number: 6680035
    Abstract: A hydrometallurgical process is provided for leaching nickeliferous laterite ores at temperatures below the boiling point of the pulp and at atmospheric pressure. The high iron fraction of the laterite, referred to as limonite, is first contacted with concentrated sulfuric acid to partially or completely dissolve the iron and nickel into solution. A reducing agent is used to keep the redox potential in solution below 1000 mV to enhance cobalt dissolution and more advantageously between 1000 and 900 mV to avoid reduction of ferric iron. Further mixing of the leach slurry in the presence of sodium, potassium, or ammonium allows formation of iron jarosite at ambient pressure. The resulting acid from iron hydrolysis is neutralized with the low iron fraction of the laterite ore (saprolite), thereby dissolving nickel into solution. The resulting final leach slurry can then be treated with conventional methods to recover nickel and cobalt from solution.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: January 20, 2004
    Assignee: BHP Minerals International Inc.
    Inventors: J. Carlos Arroyo, David A. Neudorf
  • Patent number: 6379636
    Abstract: A process is provided for the leaching of both the “limonite” (Fe approx. ≧25% and Mg approx. ≧6%) and “saprolite” (Fe approx. ≦20% and Mg approx. ≧10%) fractions of typical nickel and cobalt bearing laterite ore. The low magnesium fraction of the laterite ore is leached with sulfuric acid at high pressure and temperature to solubilize the metal values while precipitating most of the solubilized iron as hematite or other iron compounds and a portion of the dissolved aluminum as alunite or other aluminum compounds. After reducing the pressure of the leach slurry to approximately atmospheric pressure, the pregnant leach slurry or solution is contacted with the high magnesium fraction of the ore to solubilize most of the nickel contained in the high-magnesium ore fraction while dissolving only a small portion of the iron content of the high magnesium ore fraction.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: April 30, 2002
    Assignee: BHP Minerals International, Inc.
    Inventors: J. Carlos Arroyo, James D. Gillaspie, David A. Neudorf, Erik M. Weenink
  • Publication number: 20020041840
    Abstract: A hydrometallurgical process is provided for leaching nickeliferous laterite ores at temperatures below the boiling point of the pulp and at atmospheric pressure. The high iron fraction of the laterite, referred to as limonite, is first contacted with concentrated sulfuric acid to partially or completely dissolve the iron and nickel into solution. A reducing agent is used to keep the redox potential in solution below 1000 mV to enhance cobalt dissolution and more advantageously between 1000 and 900 mV to avoid reduction of ferric iron. Further mixing of the leach slurry in the presence of sodium, potassium, or ammonium allows formation of iron jarosite at ambient pressure. The resulting acid from iron hydrolysis is neutralized with the low iron fraction of the laterite ore (saprolite), thereby dissolving nickel into solution. The resulting final leach slurry can then be treated with conventional methods to recover nickel and cobalt from solution.
    Type: Application
    Filed: May 24, 2001
    Publication date: April 11, 2002
    Inventors: J. Carlos Arroyo, David A. Neudorf
  • Patent number: 6350420
    Abstract: A process is provided for the direct recovery of nickel and cobalt from a nickeliferous oxide ore leach slurry by ion exchange. A nickeliferous ore is leached with mineral acid to solubilize the metals. The resulting leach slurry is contacted with ion exchange resin, which selectively loads the nickel and cobalt from the pulp. The resin is separated from the leach slurry by screening and then stripped with an acidic solution. After stripping, the resin is returned to the loading cycle. Nickel and/or cobalt can be recovered in substantially pure form from the eluate by known processes. The metal-depleted slurry proceeds to waste treatment and disposal. This process eliminates the difficult solid/liquid separation, which would otherwise be required to recover metals values from the pregnant leach slurry.
    Type: Grant
    Filed: February 29, 2000
    Date of Patent: February 26, 2002
    Assignee: BHP Minerals International, Inc.
    Inventors: Willem P. C. Duyvesteyn, David A. Neudorf, Erik M. Weenink
  • Publication number: 20020006370
    Abstract: A process is provided for the leaching of both the “limonite” (Fe approx. ≧25% and Mg approx. ≦6%) and “saprolite” (Fe approx. <20% and Mg approx. ≧10%) fractions of typical nickel and cobalt bearing laterite ore. The low magnesium fraction of the laterite ore is leached with sulfuric acid at high pressure and temperature to solubilize the metal values while precipitating most of the solubilized iron as hematite or other iron compounds and a portion of the dissolved aluminum as alunite or other aluminum compounds. After reducing the pressure of the leach slurry to approximately atmospheric pressure, the pregnant leach slurry or solution is contacted with the high magnesium fraction of the ore to solubilize most of the nickel contained in the high-magnesium ore fraction while dissolving only a small portion of the iron content of the high magnesium ore fraction.
    Type: Application
    Filed: November 3, 1999
    Publication date: January 17, 2002
    Inventors: J. CARLOS ARROYO, JAMES D. GILLASPIE, DAVID A. NEUDORF, ERIK M. WEENINK
  • Patent number: 6261527
    Abstract: A process is provided for leaching nickeliferous laterite ores by hydrometallurgical methods at temperatures below the boiling point of the pulp and at atmospheric pressure from which high overall nickel and cobalt extractions are obtained. The high iron fraction of the laterite, referred to as limonite, is first contacted with a concentrated mineral acid to partially or completely dissolve the iron and nickel in solution. During this process, a reducing agent is used to keep the redox potential in solution below 1000 mV to enhance cobalt dissolution and more advantageously between 1000 and 900 mV to avoid reduction of ferric iron. Further mixing of the leach slurry in the presence of sodium, potassium, or ammonium will allow the formation of iron jarosite at ambient pressure. The resulting acid from iron hydrolysis is neutralized with the low iron fraction of the laterite ore (saprolite) dissolving nickel into solution.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: July 17, 2001
    Assignee: BHP Minerals International Inc.
    Inventors: J. Carlos Arroyo, David A. Neudorf
  • Publication number: 20010001650
    Abstract: A process is provided for the selective recovery from an impure solution of pure nickel and cobalt solutions, suitable for electrolysis of the respective metals. The impure solution may be that obtained from acid leaching of nickel/cobalt bearing laterite or oxide ore. The impure solution is contacted with a solid ion exchange resin to selectively extract nickel and cobalt, while rejecting at least one element of the group manganese, magnesium, calcium, iron(II), and chromium(III). The ion exchange resin contains bis-picolyl amine as the primary chelating group. The impure solution has sufficiently low levels of chromium(VI) and copper to allow repeated use of the ion exchange resin. The metal-bearing resin is washed and then stripped with an acid solution. This solution is then contacted with a water-immiscible organic phase for the selective extraction of cobalt, leaving nickel in the raffinate as a substantially pure nickel solution.
    Type: Application
    Filed: March 9, 1999
    Publication date: May 24, 2001
    Applicant: William P.C. Duyvesteyn
    Inventors: WILLEM P. C. DUYVESTEYN, DAVID A. NEUDORF, ERIK M. WEENINK, JAMES S. HANSON
  • Patent number: 4915919
    Abstract: An improved method for selectively rcovering Ge from acidic solution containing Ge and typically Zn, As, Cd, Sb, In, Cu and Fe (II) by multistage, countercurrent liquid-liquid extraction is described. The extractant used in the organic phase is an oxime, for example, 5,8-diethyl-7-hydroxy-6-dodecanone oxime, mixed with at least one alkylphosphoric acid, for example either di-2-ethylhexyl phosphate alone or admixed with mono-2-ethylhexyl phosphate, dissolved in a hydrocarbon diluent. This mixed system shows better efficiency and selectivity for germanium than known systems using either oximes or alkylphosphoric acids separately.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: April 10, 1990
    Assignee: Cominco Ltd.
    Inventors: Daniel A. D. Boateng, David A. Neudorf, Victor N. Saleh