Granted Patent
Utility
US 4,249,909 · App. 06/043,857
Drying and passivating wet coals and lignite
Inventor:
Alfred G. Comolli
Patented Case
View Patent ↗
Granted: Feb 10, 1981
Filed: May 30, 1979
Inventor
Alfred G. Comolli
Assignee (at issue)
Hydrocarbon Research, Inc.
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.