Effects and Mechanism of Different Grinding Media on the Flotation Behaviors of Beryl and Spodumene

The flotation behavior of beryl and spodumene (typical silicate minerals) was studied at wet-grinding conditions with different grinding mediums, with dodecylamine or sodium oleate as the collector. The mechanism of potential influence of the grinding medium to the flotation behavior was investigated through measuring zeta potential of pure minerals, micro scanning by X-ray photoelectron spectroscopy (XPS), surface interaction simulation and etc. The test data suggested that, with dodecylamine as the collector and relatively lower pH, the recoveries of beryl and spodumene are higher with zircon balls as wet-grinding media than those with iron balls, while in the higher pH, the recovery difference became smaller. With sodium oleate as a collector, within the same pH environment, the recovery of beryl and spodumene under zircon ball wet-grinding is lower than those under iron wet-grinding. We observed formation of iron-hydroxyl complexes on the mineral surface after iron ball grinding, which are significant influence on the flotation behavior of silicate minerals. Furthermore, for iron wet-grinding, the iron adsorbed on the mineral surface increased the adsorption energy between laurylamine (cationic collector) and silicate minerals, which inhibited the interaction between collectors and minerals. On the other hand, the interaction energy between sodium oleate (anion collector) and silicate minerals was decreased, which promoted the interaction between collectors and minerals.