High grade deposits were mined in the early stages of the activity. No attention was paid to maximizing the use of the deposits. Even nowadays, millions of tons of useful minerals are discarded every year into tailings ponds. This study investigated the possibility of economically retrieving ultrafine tailings (slimes) from an iron ore concentrator via reverse cationic flotation. The promising results of the bench scale tests led to carrying out pilot-scale tests. It was observed that a reverse cationic column flotation process, using high depressant dosage was selective, yielding high levels of iron recovery, approximately 60% mass recovery and 80 % metallic recovery in the flotation stage, from 9 to 12 % of Fe in the tailing and from 0,55 % to 0,90 % of SiO2 in the concentrate (SiO2+Al2O3 < 2,00 %). The ultrafines flotation is an economic alternative for increasing the recovery in mineral processing operations. The flotation of ultrafines may also be evaluated for decreasing or treating effluents disposed to the environment.
Flotation; ultrafines; iron ore
