Adsorption mechanism of mixed collector systems on hematite flotation

Abstract

Adsorption mechanism of mixed cationic C12 amine and anionic sulphate/oleate collectors was investigated on hematite through Hallimond flotation studies. The flotation response of hematite independently with cationic and anionic collectors and with mixed cationic/anionic collector systems is assessed. Hallimond flotation response of hematite as a function of pH and collector concentration was investigated. The study revealed that hematite flotation recovery is maximum at acidic pH with sulphate, at neutral pH 6–7 with oleate, and at basic pH about 9.5 with C12 amine. It is the first time that the hematite flotation results show an increased adsorption of cationic collector in the presence of anionic collector apart from its own co-adsorption. Flotation results indicate the presence of oleate increased the C12 amine adsorption due to a decrease in the electrostatic head–head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail–tail hydrophobic bonds.