Granted Patent
Utility
US 6,436,169 · App. 09/799,265
Method of operating a copper smelting furnace
Inventors:
Yushiro Hirai, Mitsumasa Hoshi
Patented Case
View Patent ↗
Granted: Aug 20, 2002
Filed: Mar 5, 2001
Inventors
Yushiro Hirai
Mitsumasa Hoshi
Assignee (at issue)
Nippon Mining & Metals Co., Ltd.
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.