Granted Patent
Utility
US 4,605,439 · App. 06/708,203
Recovery of gold from refractory auriferous iron-containing sulphidic material
Inventor:
Donald R. Weir
Patented Case
View Patent ↗
Granted: Aug 12, 1986
Filed: Mar 4, 1985
Inventor
Donald R. Weir
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.