Magnetic separation of weakly magnetic copper minerals

High Gradient Magnetic Separation of chalcopyrite and bornite, both weakly magnetic copper minerals with mass susceptibilities of about 0.1 × 10^-6m³/kg and 0.2 × 10^-6m³/kg respectively, has been performed. Initially pure mineral samples were processed before turning to copper samples with decreasing content of the minerals. These were: a concentrate, flotation tailings and a real ore. The recovery of these minerals was good, ranging from 90% for the concentrate to 70% for the tailings and ore. The grade was rather poor except for the ore where the grade of the magnetic minerals in the mags is almost three times higher than in the feed.