Granted Patent
Utility
US 4,594,102 · App. 06/532,331
Recovery of cobalt and nickel from sulphidic material
Inventors:
Donald R. Weir, Derek E. Kerfoot, Michael E. Chalkley
Patented Case
View Patent ↗
Granted: Jun 10, 1986
Filed: Sep 15, 1983
Inventors
Donald R. Weir
Derek E. Kerfoot
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.