Granted Patent
Utility
US 4,545,963 · App. 06/536,013
Process for separately recovering zinc and lead values from zinc and lead containing sulphidic ore
Inventors:
Donald R. Weir, Ian M. Masters, Barry N. Doyle, Michael E. Chalkley
Patented Case
View Patent ↗
Granted: Oct 8, 1985
Filed: Sep 26, 1983
Inventors
Donald R. Weir
Ian M. Masters
Barry N. Doyle
Michael E. Chalkley
Assignee (at issue)
Sherritt Gordon Mines Limited
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.