Granted Patent
Utility
US 4,483,838 · App. 06/534,421
Treatment of contaminated phosphoric acid to recover usable acid therefrom
Inventor:
Donald L. Sculthorpe
Patented Case
View Patent ↗
Granted: Nov 20, 1984
Filed: Sep 21, 1983
Inventor
Donald L. Sculthorpe
Assignee (at issue)
Stauffer Chemical 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.