Theoretical study on the flotation and adsorption behavior of dodecylamine on hydroxide minerals

Abstract

This study investigated the adsorption behavior of dodecylamine (DDA) on brucite, diaspore, and limonite through flotation experiments, infrared spectrum (IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and E–DLVO theoretical calculations. Flotation results indicate that compared with brucite, DDA significantly improves the floatability of diaspore and limonite. IR and SEM analysis confirmed that DDA can adsorb on the surfaces of the three minerals, which can be demonstrated by an increase in carbon content, a decrease in the proportion of metal elements, and the presence of N element. AFM shows significant changes on the surface of hydroxide minerals, such as an increase in cross–sectional height and roughness after DDA treatment. E–DLVO calculation further elucidates that DDA reduces electrostatic repulsion and enhances hydrophobic interactions between mineral particles and bubbles while maintaining van der Waals interactions, thereby promoting particle bubble adhesion. These findings reveal the adsorption mechanism of DDA at the interface of hydroxide minerals and provide theoretical guidance for optimizing the design of collectors for hydroxide minerals.