Granted Patent
Utility
US 5,912,401 · App. 08/863,661
Pyrometallurgical smelting method of copper
Inventors:
Takayoshi Fujii, Susumu Akagi, Yutaka Yasuda, Yoshiaki Suzuki
Patented Case
View Patent ↗
Granted: Jun 15, 1999
Filed: May 27, 1997
Inventors
Takayoshi Fujii
Susumu Akagi
Yutaka Yasuda
Yoshiaki Suzuki
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.