Granted Patent
Utility
US 5,128,047 · App. 07/512,653
Sequential separation of metals by controlled pH precipitation
Inventors:
John M. Stewart, George Hanki Chan
Patented Case
View Patent ↗
Granted: Jul 7, 1992
Filed: Apr 20, 1990
Inventors
John M. Stewart
George Hanki Chan
Assignee (at issue)
Rhone-Poulenc, 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.