Granted Patent
Utility
US 4,235,854 · App. 05/827,741
Method for purifying wet process phosphoric acid
Inventors:
Hudson C. Smith, Wesley W. Atwood, John S. Myrick
Patented Case
View Patent ↗
Granted: Nov 25, 1980
Filed: Aug 25, 1977
Inventors
Hudson C. Smith
Wesley W. Atwood
John S. Myrick
Assignee (at issue)
Occidental Petroleum
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.