Patents by Inventor Gavin Kerry Wyllie Freeman

Gavin Kerry Wyllie Freeman 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: 6949232
    Abstract: There is provided an improvement in a process for producing cobalt (III) hexammine sulphate which process comprises oxidatively pressure leaching nickel cobalt sulphides in an ammoniacal ammonium sulphate solution. The nickel and cobalt sulphides are oxidized to sulphates, and an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state is produced. The ammoniacal leach liquor is combined with ammonia to precipitate the triple salt of cobalt (III) hexammine sulphate, nickel (II) hexammine and ammonium sulphate which is further treated to produce a crystalline cobalt (III) hexammine sulphate and a nickel enriched leach liquor. The improvement involves the provision of a second oxidative pressure treatment effective to maximize the formation of the desired cobalt (III) hexammine ion, prior to the triple salt precipitation step.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: September 27, 2005
    Assignee: Sherritt International Corporation
    Inventors: Gavin Kerry Wyllie Freeman, Ockert Gerbrandt Pauw, Russell Peter Kofluk, James John Budac
  • Publication number: 20030223928
    Abstract: There is provided an improvement in a process for producing cobalt (III) hexammine sulphate which process comprises oxidatively pressure leaching nickel cobalt sulphides in an ammoniacal ammonium sulphate solution. The nickel and cobalt sulphides are oxidized to sulphates, and an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state is produced. The ammoniacal leach liquor is combined with ammonia to precipitate the triple salt of cobalt (III) hexammine sulphate, nickel (II) hexammine and ammonium sulphate which is further treated to produce a crystalline cobalt (III) hexammine sulphate and a nickel enriched leach liquor. The improvement involves the provision of a second oxidative pressure treatment effective to maximize the formation of the desired cobalt (III) hexammine ion, prior to the triple salt precipitation step.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 4, 2003
    Inventors: Gavin Kerry Wyllie Freeman, Ockert Gerbrandt Pauw, Russell Peter Kofluk, James John Budac
  • Patent number: 6267800
    Abstract: A process for producing cobalt metal powder from nickel-cobalt sulphides wherein said nickel-cobalt sulphides are leached in an ammoniacal ammonium sulphate solution under an elevated pressure of an oxygen bearing gas, at a temperature of at least 80° C., with an effective ammonia to metals mole ratio in the range of 5:1 to 6.5:1 to oxidize the nickel and cobalt sulphides to sulphates, and to produce an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state, and an ammoniacal ammonium sulphate leach residue containing a cobalt (III) hexammine sulphate-calcium sulphate double salt.
    Type: Grant
    Filed: April 11, 2000
    Date of Patent: July 31, 2001
    Assignee: Sherritt International Corporation
    Inventor: Gavin Kerry Wyllie Freeman
  • Patent number: 6264904
    Abstract: There is provided a process for the recovery of cobalt as cobalt (III) hexammine sulphate, comprising adding an effective amount of a calcium sulphate slurry to an ammoniacal ammonium sulphate solution containing cobalt (III) hexammine sulphate to thereby selectively precipitate a cobalt (III) hexammine sulphate-calcium sulphate double salt. The solution containing other base metal impurities is separated from the cobalt (III) hexammine sulphate-calcium sulphate double salt precipitate. An effective amount of an ammonium carbonate containing solution is added to the double salt precipitate to thereby redissolve cobalt (III) hexammine sulphate and precipitate calcium carbonate.
    Type: Grant
    Filed: April 11, 2000
    Date of Patent: July 24, 2001
    Assignee: Sherritt International Corporation
    Inventor: Gavin Kerry Wyllie Freeman