INORGANICCHEMICALSINDUSTRY ›› 2008, Vol. 0 ›› Issue (10): 0-0.

   

Dealkalization and reclaiming valuable Ti and Sc from red mud

Sun Daoxing   

  • Online:2008-10-10 Published:2008-10-10

Abstract: Red mud is the residual of extracting alumina from bauxite by alkali.The study on dealkalization and distilling Ti and Sc from red mud was made.The conditions of red mud dealkalization with lime were:dosage of CaO was 5%~8% (mass fraction) that of red mud.The mass ratio of milk of lime (mass fraction of CaO is 20%) and red mud was (3~5)∶1.The overall base (mass fraction of R<SUB>2</SUB>O) after exacting 2 h at 80~90 ℃ was lower than 1.0% when the particle size of red mud was less than 180 μm.The lixiviating process for reclaiming Ti and Sc with acid by two steps was obtained too. Firstly,lixiviated with hydrochloric acid (6.0 mol/L).The hydrochloric acid solution which obtained from first step would be extracted by 1% of P507.After stripping by 2.0 mol/L NaOH solution at 50 ℃,the extracting rate of Sc reached above 90%.Secondly,lixiviated with sulfuric acid (17.1 mol/L).The mass ratio of sulfuric acid and red mud was 3∶1 at 200 ℃ for 2 h.The yield of TiO<SUB>2</SUB> was over 95%.<BR>