Abstract: Flotation tests， Zeta potential measurements， infrared spectrum analyses， EDLVO calculations and SEM analyses were used to investigate the effect of citric acid on entrainment behavior of fine chlorite in hematite reverse flotation. Flotation results illustrated that citric acid promotes entrainment behavior of fine chlorite， and is conducive to removing chlorite in concentrate. Zeta-potential tests and infrared spectrum analyses indicated that adsorption of citric acid on the surfaces of chlorite and hematite increases their electronegativity and enhances the electrostatic repulsion between hematite and chlorite particles. EDLVO calculations demonstrated that the attraction between hematite and fine chlorite is transformed into repulsion after interacting with citric acid， and the calculation results are consistent with those of SEM.

Key words: citric acid, chlorite, entrainment, hematite, EDLVO calculations, interaction