Simultaneous use of direct and reverse flotation in the production of iron ore concentrate plant

Abstract The exploitation of low-grade iron ore deposits represents the current scenario for this business. Thus arise several types of research that aim at improvements and innovations as solutions to such situation. Therefore, herein, suggested is an alternative route for iron ore flotation that targets a higher mass recovery with concentrate within the market specification. First, the sample was deslimed at 38 µm and with the underflow a cut was performed in the 74 µm cyclone in order to separate the coarse particles from the fine. With the coarse particles, i.e. with the underflow, there a reverse flotation was carried on obtaining a concentrate with 67.7% of Fe and 0.9% of SiO2. In the fine particle overflow, direct flotation was done, generating a low-quality concentrate with 40.9% of Fe and 39.7% of SiO2. The mass recovery in direct flotation was 88% and in the reverse flotation was 61.1%. The concentrate generated from two flotations had a mass recovery of 67.4% with a content of Fe of 53.4% and 21.6% SiO2