Comparison between the effect of microwave irradiation and conventional heat treatments on the magnetic properties of chalcopyrite and pyrite

The effect of microwave radiation and conventional heat treatments of chalcopyrite and pyrite on their magnetic properties was investigated. Magnetic susceptibility of chalcopyrite increased significantly by increasing microwave power and treatment time. Pyrite magnetism was affected only at 500 W microwave power. On the other hand, magnetic susceptibility of both chalcopyrite and pyrite increased significantly by increasing heating temperature. X-ray diffraction and XPS characterization showed that the formation of more magnetic phases after chalcopyrite and pyrite treatment is the reason behind their increased magnetism. Dry magnetic separation of individual treated minerals at several magnetic field strengths from 0.5 Tesla to 2 Teslas was conducted. The results suggest that selective magnetic separation of chalcopyrite from pyrite is possible only in case of microwave treatment due to its selective effect in favor of chalcopyrite at lower power levels compared to pyrite. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.