Granted Patent
Utility
US 4,996,038 · App. 06/909,708
Heat recovery from concentrated sulfuric acid
Inventors:
Donald R. McAlister, Steven A. Ziebold
Patented Case
View Patent ↗
Granted: Feb 26, 1991
Filed: Sep 19, 1986
Inventors
Donald R. McAlister
Steven A. Ziebold
Assignee (at issue)
Monsanto Company
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.