Patent ID: 6669852
Filing Date: 2003-12-30
Classification: B01D,C01F,C22B,Y02P

Abstract:
A method for separating goethite-containing red mud contained in a sodium aluminate solution which is obtained by heating an alumina ore containing goethite as an iron component with an alkaline solution at 110-1600C, which method comprises adding a settling aid formed of a water-soluble polymer including, as an effective component, a copolymer having an average molecular weight of at least 2,000 and containing, as monomer components, a divalent moiety of a vinylhydroxamic acid compound or a salt thereof (A); a divalent moiety (meth) acrylic acid or a salt thereof (B); and a divalent moiety of (meth) acrylamide (C), to thereby settle the red mud and separate the settled red mud wherein the settling aid formed of the water-soluble polymer contains, in a amount of at least 20 mass %, the copolymer containing, as a monomer component, a divalent moiety formed of a vinyhydroxamic acid compound or salt thereof (A), and wherein the ratio of the vinylhydroxamic acid compound or salt thereof serving as monomer component (A) to the total monomer component is at least 5 mole.