Silica and Iron Recovery from a Residue of Iron Ore Flotation

Abstract

A study of silica and iron recovery from the iron ore concentration tailing is presented. The residue is composed of 40.1% Fe, 33.4% SiO 2 , 8.31% Al 2 O 3 , 0.08% P, and 0.34% MnO. The developed process of silica and iron recovery consisted of size classification, magnetic separation, and removal of impurities by leaching. A concentration of SiO 2 from 33.4% to 67.0%, with 60.0% of mass reduction, was achieved by size classification. After magnetic separation, the SiO 2 grade increased from 67.0% to 95.0%, in non-magnegtic fraction and iron increased from 40.1% to 60.2% in magnetic fraction. The iron content in magnetic fraction achieved the commercial grade. In order to increase the content of silica, the impurities removal from the non-magnetic fraction was studied. The leaching agents investigated were HCl, H 2 SO 4 , HNO 3 , HF, C 6 H 8 O 7 , (COOH) 2 . 2H 2 O and NaOH. A concentration of 98.0% SiO 2 was attained with the acid digestion.