Effects and mechanism of different grinding media on the flotation behaviors of typical silicate minerals

The flotation behavior of typical silicates was studied at wet grinding conditions with different grinding media (iron ball and zircon ball) when dodecylamine or sodium oleate was chosen as a collector. The mechanism of these systems was systematically il-lustrated through measuring the zeta potential of pure minerals and micro scanning by X-ray photoelectron spectroscopy (XPS). When dodecylamine is chosen for a collector, below the optimum pH value, the recoveries of zircon, beryl, spodumene and quartz are higher by zircon balls as grinding media than those by iron balls. Above the optimum pH value, the recoveries of these four silicates are very similar whether by iron balls or zircon balls. However, different grinding methods have little effects on the recovery of feldspar. The recoveries of these five silicates with iron balls as grinding media are higher than those with zircon as grinding media when sodium ole-ate is chosen as a collector. The results show that the zeta potential of zircon, beryl, spodumene and quartz is higher by zircon balls, compared with iron balls. So the recoveries of these four minerals are higher by zircon balls versus iron balls when dodecylamine is chosen as a collector. The Fe content on the surface of these five minerals is higher significantly by wet grinding with iron balls, com-pared with zircon balls. So the recovery of the former grinding methods is higher than the latter because of activation by iron ions.