Abstract: Aimed at sodium oleate system, the effect of Mg2+ on the flotation behavior of muscovite was investigated then the activation mechanism of Mg2+ on muscovite was detected by means of flotation solution chemical, Zeta potential and XPS spectra etc. The result shows that muscovite can be activated significantly by Mg2+ under alkaline conditions and the greater pH value, the better activation effect of Mg2+ on the muscovite. The muscovite recovery rate reached 82. 20% when the amount of sodium oleate and Mg2+ was 9. 20 × 10 -4 mol/L and 3. 44 × 10 -4 mol/L respectively at pH=12. The radical activation cause of Mg2+ on muscovite is it can enhance oleate ions' electrostatic adsorption on local positive region of muscovite surface and increase the reaction probability of oleate ions with reactive Al and Si on muscovite surface. Furthermore, the magnesium ion covering on muscovite surface can react with oleic acid ions to generate hydrophobic magnesium oleate. So muscovite floatability can be significantly improved under the combined action of these three factors.

Key words: muscovite;sodium oleate;magnesium ion;activation