*M.E. Amosah1, M. Yvon1, J. Zhou1, K.P. Galvin1
1ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, University of Newcastle, Callaghan, NSW 2308, Australia
Abstract: Due to the depletion of high-grade mineral deposits there is increasing demand for the reprocessing of minerals from tailings dams. However, tailings reprocessing can present several challenges due to the presence of slimes: reduced selectivity and kinetics resulting in low recovery, excessive entrainment, and high reagent consumption. This research focussed on a previously intractable problem, the processing of a low-grade cassiterite (SnO2) feed from a tailings dam. Conventional technologies have failed to achieve viable recoveries and saleable grades. Therefore, gravity separation and desliming were applied using the RefluxTM Classifier, targeting the tin down to ~ 10 µm, followed by flotation. Experiments were performed using an inclined channel spacing of 1.8 mm at ~5 t/m2/h. Recoveries of up to 94% above 20 µm and 50% below 20 µm were achieved. Importantly, the deslimed product permitted highly effective recovery of the tin by flotation, with final decanted product grades higher than 30 wt.% tin, and an overall recovery of up to 35%. The scope for further improvement in the grade and recovery is discussed.
Keywords: Slimes, Cassiterite, Tailings, Gravity separation, RefluxTM Classifier, Inclined channels, Flotation