Patent ID: 7070696
Filing Date: 2006-07-04
Classification: C02F,Y10S

Abstract:
1. A process of flocculating and dewatering an aqueous suspension of suspended solids comprising, introducing into the suspension, (a) substantially linear cationic polymer, (b) structured polymer, in which polymer (b) has ionic regain greater than 20% and is cationic wherein said ionic regain is calculated as (x−y)/x multiplied by 100 where x is the ionicity of the polymer (b) measured after applying standard shear and y is the ionicity of the polymer (b) before applying standard shear characterised in that the polymers are introduced into the substrate sequentially and polymer (a) is added first then polymer (b) to flocculate said suspended solids, and dewatering said aqueous suspension, wherein polymers (a) and (b) are copolymers of acrylamide and at least one cationic monomer selected from the group consisting of quaternary ammonium and acid salts of dimethyaminoethyl (meth) acrylate, quatemary ammonium and acid salts of dimethylaminoethyl (meth) acrylamide, and diallyldimethyl ammonium chloride.