STUDIES OF CHARACTERIZATION AND CONCENTRATION OF COMPACT ITABIRITE OF THE SERRA AZUL COMPLEX, MG

The Lagoa das Flores Mine is an important iron ore deposit located at the Serra Azul complex in the Northwestern border of the Ferriferous Quadrangle, Minas Gerais, where other important mines also occur, such as Arcelor Mittal, Usiminas, MBL and MMX. Presently 2.2 Mt/year of waste are generated; 70% of this waste is comprised by compact itabirite whose mineral resource is of the order of 370 Mt. The goals are to perform a mineralogical characterization and the development of process routes for this ore type by bench scale testing. The latter was carried out by work index and abrasion index determinations and magnetic concentration, desliming and flotation testing. The ore was composed by quartz, martitic hematite and minor magnetite; the average iron content was 34.3% and the quartz liberation degree was 92% below 0.075 mm. The best processing route are grinding to –0.15 mm, followed by medium and high strength field magnetic concentration, regrinding to –0.053 mm and reverse cationic flotation. Therefore, a final concentrate with 67.8% Fe, 1.84% SiO2 contents and metallic recovery of 83% is obtained