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:
Apr. 17, 2001
Filed:
Oct. 22, 1998
Bryan Hiscox, Rigaud, CA;
Alcan International Limited, Montreal, CA;
Abstract
A method of forming and classifying a precipitate containing large, coarse and fine particles from a super-saturated precipitating mother slurry, e.g. sodium aluminate from the Bayer process. The method comprises separating the precipitating mother slurry into a plurality of separate streams, introducing each stream into a vessel provided with an agitated lower zone and a quiescent upper zone to form the precipitate, with the large and coarse particles remaining as a slurry in the agitated lower zone and the fine particles migrating to the quiescent zone, removing product slurry from the lower agitated zone, and removing spent liquor containing the fine particles from the quiescent upper zone. The invention also provides apparatus for carrying out the method. The combined precipitation and partial classification (separation of fine particles) makes it possible to deal with high solids charges increasingly encountered in industrial processes.