Patent ID: 6077486
Filing Date: 2000-06-20
Classification: B01D,C01F

Abstract:
A process for reducing the level of colloidal iron in a Bayer process stream, comprising (a) providing a Bayer process stream having (i) a pH of 11 or greater, (ii) a sodium aluminate concentration of greater than 100 grams per liter, and (iii) containing colloidal iron; (b) providing an amidoxime polymer; (c) intermixing said Bayer process stream with about 1 milligram to about 500 milligrams of said amidoxime polymer per liter of said Bayer process stream, to form a mixture comprised of sodium aluminate solution and an insoluble polymer-iron complex, and (d) separating said insoluble polymer-iron complex from said sodium aluminate solution to obtain a purified sodium aluminate solution.