Granted Patent
Utility
US 4,386,963 · App. 06/304,272
Grinding aids for granular blast furnace slag
Inventor:
Bruce A. Lange
Patented Case
View Patent ↗
Granted: Jun 7, 1983
Filed: Sep 21, 1981
Inventor
Bruce A. Lange
Assignee (at issue)
W. R. Grace & Co.
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.