Granted Patent
Utility
US 3,988,151 · App. 05/587,106
Liquid ion exchange process for the recovery of copper and nickel
Inventors:
Roald R. Skarbo, David L. Natwig
Patented Case
View Patent ↗
Granted: Oct 26, 1976
Filed: Jun 16, 1975
Inventors
Roald R. Skarbo
David L. Natwig
Assignee (at issue)
Kennecott Copper Corporation
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.