Depression of iron sulphide flotation in zinc roughers

Three methods of improving zinc concentrate grade in the flotation of two massive sulphide ores were investigated. These methods involve the use of oxygen gas conditioning, copper specific collectors or selective polymeric depressants. The results obtained demonstrated that all three methods provide high zinc concentrate grades through depression of iron sulphide minerals. It was also found that by combining two methods, reagent consumption could be decreased without decreasing overall performance.