Enhancement mechanism of metal ions on the flotation behavior of muscovite in sodium oleate system

Metal ions have been employed to improve the flotation efficiency of muscovite, yet the underlying enhancing mechanisms remain unclear. In this study, we systematically investigated the improvement in muscovite flotation by adding metal ions with different valence states (K⁺, Ca²⁺, and Al³⁺). Flotation experiments revealed that the muscovite recovery rate increased from approximately 10 % to over 70 % with the addition of Ca²⁺ and Al³⁺, while it decreased to less than 1 % with the introduction of K⁺. Fourier Transform Infrared spectrophotometer (FT-IR), contact angle tests, and zeta potential analysis confirmed the significant changes in the surface properties of muscovite after binding with K⁺, Ca²⁺, and Al³⁺. Surface electrostatic potential (ESP) results indicated that the muscovite surface exhibited positive electrostatic potential in the presence of these metal ions, facilitating the adsorption of collectors (NaOL) and enhancing the flotation recovery of muscovite. Furthermore, molecular dynamics (MD) simulations demonstrated that the enhancing effect of Al(OH)₂⁺ on collector adsorption was more pronounced than that of AlOH²⁺, attributed to the better dispersion of the OL-Al(OH)₂ complex compared to the 2OL-AlOH complex. These findings provide new insights into the complexation between metals and anionic collectors, and improving the flotation effect of minerals through metal ions has significant potential for industrial applications.