The behaviour of chalcopyrite in flotation columns in a copper cleaner circuit was evaluated by an image analysis and materials balancing technique to compare chalcopyrite recoveries by cleaner columns with chalcopyrite recovery by conventional cleaner flotation cells. A higher recovery of free chalcopyrite grains smaller than 10 mu m was obtained by the column flotation circuit than by the conventional flotation circuit. It was also observed that pyrite and sphalerite particles smaller than 13.3 mu m are entrained in the Cu concentrates from both the column and conventional flotation circuits.