Adsorption Characteristics of Sodium Oleate on the Surface of Hydroxide Minerals

ABSTRACT This study systematically investigated the adsorption behavior of sodium oleate (NaOL) on the surfaces of brucite, diaspore, and limonite, and its effect on mineral flotation recovery. Through single mineral flotation experiments, the differences in the concentration of NaOL on the flotation recovery of three minerals were revealed: At a NaOL dosage of 50 mg/L, the highest flotation recovery of brucite, diaspore, and limonite was 62.90%, 42.50%, and 49.13%, respectively. In addition, the adsorption characteristics of NaOL at the mineral interface were elucidated by combining Fourier Transform Infrared spectroscopy (FTIR) analysis, Energy‐Dispersive X‐Ray spectroscopy (EDS), atomic force microscopy (AFM), and Extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theoretical analysis. The FTIR results indicate that the adsorption strength of NaOL on the surface of brucite is stronger than that of diaspore and limonite. EDS test results showed that after sodium oleate adsorbed on brucite, diaspore, and limonite, the content of characteristic elements on the mineral surface decreased, while the content of C and O increased significantly. AFM imaging further revealed a significant increase in the average roughness of NaOL on the surfaces of brucite, diaspore, and limonite. EDLVO theoretical calculations show that NaOL changes the hydrophobic interaction energy and total interaction energy of the three minerals from positive to negative, indicating that NaOL greatly enhances the hydrophobic interaction energy between the three mineral particles and bubbles. This study laid a theoretical foundation for the study of the adsorption characteristics and mechanism of the collector on the surface of hydroxide minerals.