Patents Assigned to Metprotech Limited
  • Patent number: 5007589
    Abstract: A source material in the form of an ore, mineral, concentrate, calcine, or reclaimed tailings is subjected to fine milling in a stirred mill having an impeller rotatable in a grinding chamber filled with grinding media. A slurry of the source material is fed, on a continuous basis, to an inlet to the grinding chamber which is generally at a low level and flows through the chamber and out of an outlet, conveniently an overflow type of outlet. The carrier liquid may be a leach solution and/or oxidizing air or oxygen can be fed to the material as it is being milled. Enhanced recoveries of gold using a cyanide leach solution as the carrier liquid can be achieved using the process.
    Type: Grant
    Filed: May 30, 1990
    Date of Patent: April 16, 1991
    Assignee: Metprotech Limited
    Inventors: Dennis E. Evans, Keith S. Liddell