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:
Mar. 24, 1992
Filed:
May. 24, 1991
Jack S Thompson, Moose Jaw, CA;
David Genders, East Amherst, NY (US);
Ormiston Mining and Smelting Co. Ltd., Moose Jaw, CA;
Abstract
A process for producing sodium hydroxide and ammonium sulfate by electrolysing an aqueous solution of sodium sulfate is disclosed. The process is carried out in a three-compartment electrolytic cell having a central compartment separated from an anode and a cathode compartment by, respectively, anion selective and cation selective ion exchange membrane. The solution of sodium sulfate is circulated through the central compartment, while solutions of sodium hydroxide and ammonium sulfate are circulated, respectively, through the cathode and the anode compartment. During the process, ammonia is added to the anolyte to at least partially neutralize sulfuric acid produced in the anode compartment and reduce the back migration of protons from the anolyte into the central compartment. As a result, high purity ammonium sulfate of commercial value higher than that of sulfuric acid is produced with high current efficiency and in concentrations higher than those achievable for sulfuric acid.