Patent ID: 7189327
Filing Date: 2007-03-13
Classification: B01D,B03D,C01D,C02F,C08F,C08L

Abstract:
1. A method of enhancing the recovery of useful coal from screenbowl centrifuge separation operations comprising a) discharging a slurry of coal into the screenbowl centrifuge; b) adding to a low shear zone of the screenbowl centrifuge, from about 0.005 lbs active polymer/ton dry solids in centrifuge to about 0.70 lbs active polymer/ton dry solids in centrifuge, of an anionic copolymer, wherein said anionic copolymer is selected from the group consisting of copolymers of acrylamide and acrylic acid and salts thereof to allow solids to be flocculated without being torn apart by shear forces; c) centrifuging the slurry to separate the flocculated solids from an effluent; and d) recovering useful coal from the slurry.