Patent ID: 6726845
Filing Date: 2004-04-27
Classification: B01D,C02F

Abstract:
A method for treating Bayer Process liquor containing red mud comprising(a) adding to the liquor a soluble synthetic flocculant and starch, wherein said soluble synthetic flocculant is selected from the group consisting of (i) homopolymers of acrylic acid, (ii) copolymers of acrylic acid and acrylamide, (iii) copolymers of acrylic acid and acrylamide modified to contain a hydroxamic acid moiety; and (iv) copolymers of acrylic acid and acrylamide modified to contain an comprises ammonium acrylate with a molecular weight greater than 10 million; and (b) adding to the liquor dextran; wherein the soluble synthetic flocculant to flocculate said red mud prior to the addition of the dextran, and wherein no additional synthetic flocculant is added to the liquor; and then (c) removing the flocculated red mud contained in the Bayer process liquor by sedimentation, centrifugation or filtration.