Abstract

High Gradient Magnetic Separation of small (5-38 µm) weakly magnetic copper mineral particles from a copper concentrate and ore has been performed. In previous work coarser fractions of these minerals, bornite and chalcopyrite, were separated successfully. The recovery of the smaller particles in the magnetic fraction decreases but their grade increases compared to the results obtained on the larger particles. At a magnetic background field of 1.3 T the concentrate was upgraded from 72% bornite and chalcopyrite to 86% with a recovery of 82% and the ore from 16% magnetic minerals to 44% with a recovery of 72%.