Granted Patent
Utility
US 4,248,837 · App. 06/011,034
Solvent extraction of copper, nickel with methyl hexyl dioxime
Inventors:
Ralph W. M. Lai, John K. Litchfield
Patented Case
View Patent ↗
Granted: Feb 3, 1981
Filed: Feb 9, 1979
Inventors
Ralph W. M. Lai
John K. Litchfield
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.