Granted Patent
Utility
US 5,846,501 · App. 08/840,239
Process for the selective recovery of the salt constituents from used hardening shop salts which contain nitrite-nitrate
Inventors:
Matthias Kremer, Georg Wahl, Eberhard Gock, Stefan Wigger, Jorg Kahler
Patented Case
View Patent ↗
Granted: Dec 8, 1998
Filed: Apr 11, 1997
Inventors
Matthias Kremer
Georg Wahl
Eberhard Gock
Stefan Wigger
Jorg Kahler
Assignee (at issue)
Durferrit GmbH Thermotechnik
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.