The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 1996
Filed:
Feb. 25, 1992
Applicant:
Inventors:
Donald W DuBois, Irwin, PA (US);
Bernard A Maloney, Murrysville, PA (US);
Stanley R Pickens, Monroeville, PA (US);
Assignee:
PPG Industries, Inc., Pittsburgh, PA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C25B / ; C25B / ;
U.S. Cl.
CPC ...
205350 ; 205516 ;
Abstract
Disclosed is an improved method of making chlorine and alkali metal hydroxide, e.g., sodium hydroxide, in an electrolytic cell of the type wherein a liquid permeable diaphragm separates the anolyte from the catholyte, said method comprising adding to the anolyte, while the cell is operating, a hydrated aluminum silicate containing clay mineral, followed by lowering the pH of the anolyte by the addition of an inorganic acid and maintaining the anolyte at said lowered pH for a time sufficient to restore the cell to a predetermined current efficiency.