ORALS

The presence of high concentrations of dissolved ions in groundwater, sea water or recycled water may alter the water structure, particle surface wettability and colloidal interactions between bubbles and particles and can have a significant effect on mineral flotation [1]. While the impact of water quality on the flotation of precious and base metal minerals is well established [2], [3], there is a lack of relevant published studies regarding the effect of water salinity on the flotation of rare earth bearing minerals. This study aims to investigate the effects of using saline water and water with high concentration of dissolved salts on the flotation of rare earth bearing minerals. Specifically, this paper attempts to quantify the effect of water quality variation on flotation recovery and grade of rare earth minerals and gain an understanding on which ions existing in saline water affect flotation behaviour. The results showed that the presence of divalent metal ions such as Mg2+ and Ca2+ leads to significant depression of monazite flotation while the presence of monovalent metal ions such as Na+ affected monazite flotation recovery to a lesser extent. Comparison of various water systems for flotation showed that bore water from Western Australia resulted in decrease in recovery of >40% after two stages of cleaning.

References:
[1] Wang, B., & Peng, Y., (2014). The effect of saline water on mineral flotation – A critical review. Minerals Engineering, 66-68, 13-24. [2] Peng, Y., Seaman, D., 2011. The flotation of slime-fine fractions of Mt. Keith pentlandite ore in de-ionised and saline water. Minerals Engineering 24 (5), 479–481. [3] Moreno, P.A., Aral, H., Cuevas, J., Monardes, A., Adaro, M., Norgate, T., & Bruckard, W., 2011. The use of seawater as process water at Las Luces copper–molybdenum beneficiation plant in Taltal (Chile). Minerals Engineering, 24(8), 852-858.