Granted Patent
Utility
US 4,900,451 · App. 07/305,232
Method of controlling manganese deposition in open recirculating aqueous systems
Patented Case
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Granted: Feb 13, 1990
Filed: Feb 1, 1989
Assignee (at issue)
Betz Laboratories, 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.