Clarification of bayer process liquors
AssigneeAllied Colloids Limited
InventorsJohn R. Field, Gillian M. Moody, Trevor K. Hunter
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Abstract
The clarification of a sodium aluminate liquor in the Bayer Process, especially the liquor obtained by Kelly filter filtration of the supernatant from the primary settling stage, is improved by flocculation with a polymer of the formula CH.sub.2 .dbd.C(R.sup.1)CONHR.sup.2 NR.sup.3 R.sup.4 wherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl.
Claims21
A process for separating inorganic suspended solids in a sodium aluminate liquor obtained in a Bayer Process wherein an effective amount of a flocculatng agent is added to the liquor containing suspended solids, the flocculating agent comprising a quaternised polymer having an intrinsic viscosity (IV) above 1 dl/g and having at least about 25% by weight quaternised recurring units derived from monomers of the formula
- CH.sub.2 .dbd.C(R.sup.1)CONHR.sup.2 NR.sup.3 R.sup.4
- wherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl, and the flocculated suspended solids are separated from the liquor.
A process for separating inorganic suspended solids from a sodium aluminate liquor obtained in a Bayer process wherein an effective amount of a flocculating agent is added to the liquor containing the suspended solids, the flocculating agent comprising a quaternised polymer having an intrinsic viscosity of above 1 dl/g and having from 95 to 25% by weight quaternised recurring groups derived from monomers of the formula
- CH.sub.2 .dbd.C(R.sub.1)CONHCH.sub.2 CH.sub.2 CH.sub.2 N(CH.sub.3).sub.2
- wherein R.sub.1 is hydrogen or methyl, and the flocculated suspended solids are separated from the liquor.
Dependencies are inferred from the claim text.