Granted Patent
Utility
US 4,243,643 · App. 05/954,647
Metallic ion removal from phosphoric acid
Inventor:
Harold E. Mills
Patented Case
View Patent ↗
Granted: Jan 6, 1981
Filed: Oct 25, 1978
Inventor
Harold E. Mills
Assignee (at issue)
Occidental Chemical 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.