Granted Patent
Utility
US 5,234,498 · App. 07/941,392
Process for fixing lead-contaminated ecologically hazardous industrial waste materials using clinoptilolite zeolite
Inventor:
Paul R. Graves, Jr.
Patented Case
View Patent ↗
Granted: Aug 10, 1993
Filed: Sep 8, 1992
Inventor
Paul R. Graves, Jr.
Assignee (at issue)
GnB
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.