Patents by Inventor Andrew R. Marchbank

Andrew R. Marchbank 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).

  • Gold recovery from refractory carbonaceous ores by pressure oxidation, thiosulfate leaching and resin-in-pulp adsorption
    Patent number: 5785736
    Abstract: A process for treatment of precious metal ores in which gold is leached from an oxidized ore slurry using a thiosulfate salt lixiviant and copper catalyst. Gold and copper are subsequently loaded onto an ion exchange resin. Copper is recovered from the resin by elution with a thiosulfate solution; gold is recovered from the resin by elution with a thiocyanate colution. Gold is recovered from the eluate by precipitation, electrowinning, or cementation.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: July 28, 1998
    Assignee: Barrick Gold Corporation
    Inventors: Kenneth G. Thomas, Christopher Fleming, Andrew R. Marchbank, David Dreisinger
  • Gold recovery from refractory carbonaceous ores by pressure oxidation and thiosulfate leaching
    Patent number: 5536297
    Abstract: A process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. The oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between 7 and 8.7 while the slurry is agitated in a stirred tank reactor system having agitated leach tanks. Gold is recovered from the gold-bearing leachate by cementation, adsorption on an adsorbent, or cyanidation.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: July 16, 1996
    Assignee: Barrick Gold Corporation
    Inventors: Andrew R. Marchbank, Kenneth G. Thomas, David Dreisinger, Christopher Fleming