Granted Patent
Utility
US 4,377,556 · App. 06/366,806
Process for removing dissolved selenium values from an acidic aqueous copper sulphate solution
Inventor:
Zoenek Hofirek
Patented Case
View Patent ↗
Granted: Mar 22, 1983
Filed: Apr 9, 1982
Inventor
Zoenek Hofirek
Assignee (at issue)
Sherritt Gordon Mines Limited
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.