Study on the effect of iron oxide-hydroxide nanoparticles on mixed flotation of bornite and molybdenite

Iron oxide-hydroxide nanoparticles have high adsorption properties, and their crystalline structure has adsorption sites for water molecules. Owing to these properties, iron oxide-hydroxide nanoparticles has been reported to alter the surface hydrophobicity of chalcopyrite, depressing its floatability. However, there is no study available on the effect of iron oxide-hydroxide nanoparticles on bornite flotation. Therefore, this study examined iron oxide-hydroxide nanoparticles for their potential as a depressant of bornite. It was found that iron oxide nanoparticles acted as a depressant of bornite in flotation tests using pure mineral. Iron oxide-hydroxide nanoparticles hydrophilized the surface of bornite, suggesting the possibility of separation of bornite and other valuable associated sulfide minerals, such as molybdenite. Based on these results, the influence of iron oxide nanoparticles on the mixed flotation of bornite and molybdenite was investigated in the presence of potassium amyl xanthate and diesel oil as copper and molybdenum collectors. The separation efficiency between bornite and molybdenite was 61.5% after employing 30 mg/L of iron oxide-hydroxide as a depressant. Under this condition, molybdenite recovery was 94.9% and bornite recovery was 33.3%. This result demonstrates the potential use of iron oxide-hydroxide as a selective depressant for bornite in the selective flotation of copper-molybdenum.