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Dewatering of Red Mud.
Pap in Floc in Biotech & Separation Sys Elsevier Sci Publ B V Asterdam 1987 Asterdam:175-185
A solid-liquid separation technique was applied to red mud, the caustic-containing residue generated when alumina is extracted from bauxite by the Bayer process. Red mud obtained from Jamaican bauxite was dewatered in laboratory batch tests and small-scale continuous tests to develop an inexpensive method of washing the mud and recovering the valuable sodium aluminate and caustic. A number of high-molecular-weight polymers were evaluated; a high-anionic powder polymer used in combination with a high-anionic emulsion-type polymer proved to be most effective. In small-scale continuous tests using a baffled tube mixer to aid floc formation and a rotating trommel to dewater the solids, slurries with an initial concentration of 10 pct solids were dewatered to 27 pct solids using 0.17 Kg of combined polymer per ton of dry solids. After the trommel treatment, the flocculated red mud was placed in a column fitted with a screen to allow released water to drain; after 15 days, the solids content increased to over 40 pct.
Pap in Floc. in Biotech. & Separation Sys., Elsevier Sci Publ. B.v., Asterdam, 1987, Pp 175-185
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Content source: National Institute for Occupational Safety and Health Education and Information Division