Granted Patent
Utility
US 4,976,776 · App. 07/323,922
Method for reduction of material containing metal oxide using a fluidized bed reactor and flame chamber
Inventors:
Hans I. Elvander, Rolf E. Malmstrom
Patented Case
View Patent ↗
Granted: Dec 11, 1990
Filed: Mar 15, 1989
Inventors
Hans I. Elvander
Rolf E. Malmstrom
Assignee (at issue)
A. Ahlstrom Corporation
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.