Granted Patent
Utility
US 4,301,973 · App. 06/104,671
Beneficiation of iron ore
Inventor:
Ralph W. M. Lai
Patented Case
View Patent ↗
Granted: Nov 24, 1981
Filed: Dec 17, 1979
Inventor
Ralph W. M. Lai
Assignee (at issue)
Kennecott Holdings Company
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.