Process evaluation of an iron ore operation using the floatability component model

Abstract

The Brucutu iron ore mine (Minas Gerais, Brazil) is Vale`s largest iron producing operation achieving around 21 million tons per annum. Evaluation of flotation performance is of high importance as even small gains can lead to large monetary benefits. Cell-by-cell samples of the froth products, selected feed and pulp-products were analyzed for flow rate, particle size distribution and chemical composition. In addition, certain samples were analyzed on an assay-by-size basis and hydrodynamic measurements of certain flotation cells were also performed. This detailed experimental dataset was then used to calibrate a floatability component model of the process. Longer mainline residence time resulted in significant Fe2O3 losses while yielding little benefit in terms of SiO2 product grade. Scavenger 2 has twice the residence time of scavenger 1 while having to treat only 10% of the SiO2, resulting in high Fe2O3 recoveries to the froth and poor separation. In addition, it is shown that the Fe2O3 exhibits true flotation behavior resulting in increased Fe2O3 losses. Simulations using the floatability component model identified avenues of process improvement to ad-dress the identified behavior. The insight provided by the simulations into the dynamics of the flotation process is invaluable for process engineers.