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:
Dec. 30, 1997
Filed:
Jul. 12, 1994
Applicant:
Inventors:
James W Smith, Toronto, CA;
Hoc Nghia Tran, Toronto, CA;
Assignee:
Thor Technology Corporation, North York, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 301 ; 162 3011 ; 423207 ;
Abstract
Sodium hydroxide is formed from sodium sulphate by a three step operation comprising converting the sodium sulphate to sodium sulphide, converting the sodium sulphide to sodium bicarbonate, and converting the sodium bicarbonate to sodium hydroxide. The operations preferably are effected in conjunction with a bleached kraft pulp mill operation, so as to utilize by-product sodium sulphate from chlorine dioxide generation to produce useful sodium hydroxide as sulphur without co-producing chlorine.