Reverse flotation of apatite from iron ore in a REFLUXTM flotation cell

Dephosphorization is essential to purify iron ore before converting it into valuable products like steel. This is carried out using the flotation process, where selectively hydrophobized phosphorus compounds like apatite impurities are recovered and a higher grade iron ore is achieved in the form of magnetite and haematite. The REFLUX TM Flotation Cell (RFC TM ) has displayed tremendous potential in coal applications and mineral processing at the lab scale. The cell has broken the operating boundaries of the conventional flotation processes, which have not been achieved before, and enabled very high upgrades and recoveries. This study applies the RFC TM for the first time for the reverse flotation of apatite from magnetite-rich iron ore. The study focuses on improving the hydrodynamic parameters without focusing on the reagents optimization. The experiments are divided into pre-experiments at lower solid concentrations, and the observations are used to formulate a Design of Experiments for solid concentrations up to 50 % (w/w), as used at the mine site. Additionally, for the first time, the Wire mesh sensor, operating in electrical resistivity mode, is fixed in the cell cross-section to determine the gas–liquid phase distribution. The mineralogical results are correlated to the observations and the measured phase distributions. • RFC TM reverse flotation removing apatite from magnetite up to 20% (w/w) solids. • Sensitivity analysis of hydrodynamic flux effects on cell performance. • Bubbly-zone liquid interface loss to underflow is the main cause of poor performance. • In-situ phase distribution via high-resolution conductivity Wire-mesh sensor.