Granted Patent
Utility
US 4,285,920 · App. 06/092,598
Solvent extraction process for preparing purified phosphoric acid and sodium phosphate salts
Inventor:
Avtar S. Jassal
Patented Case
View Patent ↗
Granted: Aug 25, 1981
Filed: Nov 8, 1979
Inventor
Avtar S. Jassal
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.