Adsorption mechanism of mixed cationic C-12 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 C-12 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 C-12 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. (C) 2011 Elsevier Ltd. All rights reserved.