Granted Patent
Utility
US 4,717,699 · App. 06/815,704
Process for acid treating clay for improved filtration
Inventor:
Grant A. Mickelson
Patented Case
View Patent ↗
Granted: Jan 5, 1988
Filed: Jan 2, 1986
Inventor
Grant A. Mickelson
Assignee (at issue)
American Colloid 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.