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:
Aug. 24, 1999
Filed:
Jan. 24, 1997
Rokhsareh Thompson, Pointe Claire, CA;
Michael Paleologou, Beaconsfield, CA;
Richard McKinnon Berry, Ile Perrot, CA;
Craig J Brown, Pickering, CA;
Michael Sheedy, North York, CA;
Pulp and Paper Research Institute of Canada, Pointe Claire, CA;
Eco-Tec Limited, Pickering, CA;
Abstract
A process using an amphoteric ion-exchange resin, also known as a 'snake-cage polyelectrolyte' resin separates kraft white liquor into sulphide-rich and caustic-rich components. The sulphide-rich component can be used in the initial stage of pulping, pretreatment of wood chips prior to pulping, or it can be used to make polysulphide-rich liquor. The caustic-rich component can be used in the final delignification phase, in place of sodium hydroxide or white liquor in oxygen delignification, pH adjustment and flue gas scrubbing. The same system can be used to separate green and polysulphide liquors into sulphide-rich and sulphide-poor components, and to remove sulphide from other mill caustic streams contaminated with sulphide.