MMIJ Annual Meeting

Chalcopyrite (CuFeS₂) is widely recognized as one of the primary sources of copper and is typically recovered from associated gangue minerals through froth flotation. However, the efficiency of this separation process can be significantly influenced by surface chemistry modifications of the mineral. Recently, there has been a growing number of studies exploring the use of nanotechnologies to modify the surface properties of the minerals. Therefore, the present study aims to systematically investigate the impact of iron-based nanoparticles—goethite (α-FeOOH) and hematite (Fe₂O₃))—on the flotation behavior of chalcopyrite. The results demonstrated that goethite nanoparticles exhibited a significant depressing effect on flotation of chalcopyrite; specifically, the addition of 30 mg/L of goethite nanoparticles reduced chalcopyrite recovery from 93% to 15% at pH 9. This pronounced decline in flotation performance suggests that goethite nanoparticles can act as effective nanodepressants by interfering with the surface hydrophobicity of chalcopyrite. Detailed studies using zeta potential analysis revealed that the opposite charge interaction between goethite nanoparticles and chalcopyrite may be the primary cause of the observed depressing effect.