Impact of flotation operational parameters on the optimization of fine and coarse Itabirite iron ore beneficiation

Abstract

This paper investigates the impact of operational parameters on the reverse flotation of Timbopeba itabirite iron ore in a pneumatic (MBE Pneuflot) flotation cell. To this end, the effects of physical and chemical parameters (i.e., collector and depressant dosage, superficial gas velocity (Jg), solids concentration, and feed rate) on the reverse flotation of iron ore are investigated in detail. Results show that increasing collector dosage increases quartz recovery, particularly for the coarser quartz where recovery increases by nearly 30%. Increasing depressant dosage results in a decrease in both quartz recovery and hematite loss, for the coarser hematite particles. In addition, increasing the feed rate does not affect quartz recovery or hematite loss, suggesting that the pneumatic flotation cell is not constrained by residence time. Furthermore, increasing the superficial gas velocity results in an increases in quartz recovery to an optimum at a Jg of around 0.6 cm/s after which it decreases significantly, particularly for the coarser particles where recovery decreases by 50%. Decreasing the solids concentration does not affect quartz recovery but results in a significant reduction in hematite loss. Here, fine and coarse hematite loss decrease from around 25% to 12% and 10% to 2%, respectively. Solids concentration and Jg are operating parameters that have the largest effect on the flotation performance of the pneumatic flotation cell. Overall, the obtained results suggest that this flotation cell should be operated at relatively low superficial gas velocities and solids concentrations. However, these findings are for a pilot scale and would need to be examined at larger scale (e.g., an industrial scale) where different operating conditions may be optimal.