关键词: 柠檬酸, 白云母浮选, 油酸钠, 抑制机理

Abstract: Citric acid is usually used as an adjustment agent in mineral processing. In order to investigate the effect regularity of citric acid on the floatability of muscovite and the action mechanism of citric acid on muscovite under sodium oleate system, different muscovite samples were characterized by means of FT-IR, flotation solution chemistry, Zeta potential and XPS spectra etc. The results showed that the floatability of muscovite could be obviously inhibited by citric acid. The muscovite recovery rate only reached 0.40% when the concentrations of sodium oleate and citric acid were 9.20×10–4 and 4.76×10–5 mol/L respectively at pH value of 6. The reason for the inhibition of the floatability of the muscovite by citric acid was that citric acid generated C6H7O7– and C6H6O72– etc. in the solution. C6H7O7– and C6H6O72– etc. could adsorb on muscovite surface, then hinder oleate ions adsorbed on muscovite surface, and the collection performance of sodium oleate on muscovite could be weakened. Meanwhile C6H7O7– and C6H6O72– etc. which adsorbed on muscovite surface aroused muscovite surface Zeta potential negative direction increase, this means that the local positive region on the surface of muscovite will decrease, therefore the electrostatic adsorption action and the chemical adsorption of oleate ions on muscovite surface was weakened. Furthermore, these ions were generated by citric acid contained strong hydrophilic groups, and adsorbed on muscovite surface that caused muscovite surface with strong hydrophilicity, this means that the muscovite could be more difficult to float up, hence the floatability of muscovite decreased significantly under the above comprehensive effect. This work can provide a certain theoretical basis for the floatation separation of muscovite, and it can also provide some degree of reference for the selection of adjustment agents in the process of muscovite flotation.

Key words: Citric acid, Muscovite flotation, Sodium oleate, Inhibition mechanism