Granted Patent
Utility
US 4,201,750 · App. 05/899,168
Processing of breunnerite to recover magnesium compounds
Inventor:
Frank Pitts
Patented Case
View Patent ↗
Granted: May 6, 1980
Filed: Apr 24, 1978
Inventor
Frank Pitts
Assignee (at issue)
Engelhard Minerals & Chemicals 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.