Granted Patent
Utility
US 6,599,414 · App. 09/924,000
Solvent extraction processes for metal recovery
Inventors:
Michael J. Virnig, G. Timothy Fisher
Patented Case
View Patent ↗
Granted: Jul 29, 2003
Filed: Aug 7, 2001
Inventors
Michael J. Virnig
G. Timothy Fisher
Assignee (at issue)
Cognis 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.