Patents Assigned to Placer Dome Technical Services, Ltd.
  • Method for thiosulfate leaching of precious metal-containing materials
    Patent number: 8821613
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.
    Type: Grant
    Filed: February 4, 2010
    Date of Patent: September 2, 2014
    Assignee: Placer Dome Technical Services Ltd.
    Inventors: Jinxing Ji, Christopher Andrew Fleming, Paul George West-Sells, Ralph Peter Hackl
  • METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS
    Publication number: 20140047954
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.
    Type: Application
    Filed: October 21, 2013
    Publication date: February 20, 2014
    Applicant: PLACER DOME TECHNICAL SERVICES LTD.
    Inventors: Jinxing Ji, Christopher Andrew Fleming, Paul George West-Sells, Ralph Peter Hackl
  • METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS
    Publication number: 20110132147
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.
    Type: Application
    Filed: February 3, 2011
    Publication date: June 9, 2011
    Applicant: PLACER DOME TECHNICAL SERVICES LTD.
    Inventors: Jinxing Ji, Christopher Andrew Fleming, Paul George West-Sells, Ralph Peter Hackl
  • METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS
    Publication number: 20100132509
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.
    Type: Application
    Filed: February 4, 2010
    Publication date: June 3, 2010
    Applicant: PLACER DOME TECHNICAL SERVICES LTD.
    Inventors: Jinxing Ji, Christopher Andrew Fleming, Paul George West-Sells, Ralph Peter Hackl
  • REDUCTION OF LIME CONSUMPTION WHEN TREATING REFRACTORY GOLD ORES OR CONCENTRATES
    Publication number: 20100024603
    Abstract: The present invention is directed to a precious metal recovery process in which basic ferric sulphates and/or jarosites are controlled by a number of mechanisms, including control of the oxidation reaction conditions in the first autoclave compartment, hot curing of the autoclave discharge slurry, and/or contacting of the autoclave feed slurry with the hot cured discharge liquid.
    Type: Application
    Filed: October 13, 2009
    Publication date: February 4, 2010
    Applicant: PLACER DOME TECHNICAL SERVICES LTD.
    Inventors: Jinxing Ji, James A. King, Christopher Andrew Fleming, Cesare Giosue Ferron
  • Method for thiosulfate leaching of precious metal-containing materials
    Patent number: 7559974
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: July 14, 2009
    Assignee: Placer Dome Technical Services Ltd.
    Inventors: Jinxing Ji, Christopher Andrew Fleming, Paul George West-Sells, Ralph Peter Hackl
  • Method for thiosulfate leaching of precious metal-containing materials
    Patent number: 7544232
    Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ heap leaching or lixiviants that include one or more blinding agents.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: June 9, 2009
    Assignee: Placer Dome Technical Services Ltd.
    Inventors: Ralph Peter Hackl, Jinxing Ji, Paul George West-Sells
  • Autoclave using agitator and sparge tube to provide high oxygen transfer rate to metal-containing solutions
    Patent number: 6368381
    Abstract: The autoclave of the present invention includes an impeller having a conduit to recirculate or introduce a molecular oxygen-containing gas into the slurry. The outlets for the gas can be located in the blades of the impeller for thorough dispersion of the gas bubbles in the slurry. A sparge tube for introducing an additional molecular oxygen-containing gas into the slurry can be used in conjunction with the impeller to provide a high molecular oxygen transfer rate to the slurry.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: April 9, 2002
    Assignee: Placer Dome Technical Services, Ltd.
    Inventors: James A. King, Jinxing Ji