Granted Patent
Utility
US 4,136,199 · App. 05/810,484
Metallic ion removal from phosphoric acid
Inventor:
Harold E. Mills
Patented Case
View Patent ↗
Granted: Jan 23, 1979
Filed: Jun 27, 1977
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.