Granted Patent
Utility
US 4,330,508 · App. 06/200,126
Removal of selenium (IV) and (VI) from acidic copper sulphate solutions
Inventors:
Donald R. Weir, Derek G. E. Kerfoot, Hugh C. Scheie
Patented Case
View Patent ↗
Granted: May 18, 1982
Filed: Oct 24, 1980
Inventors
Donald R. Weir
Derek G. E. Kerfoot
Hugh C. Scheie
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.