Granted Patent
Utility
US 6,231,640 · App. 09/324,300
Dissolving petroleum coke in molten iron to recover vanadium metal
Inventors:
Donald P. Malone, Thomas C. Holcombe
Patented Case
View Patent ↗
Granted: May 15, 2001
Filed: Jun 2, 1999
Inventors
Donald P. Malone
Thomas C. Holcombe
Assignee (at issue)
Marathon Ashland Petroleum LLC
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.