The natural flotability of chalcopyrite

Abstract

In an extensive programme of batch flotation tests on mixtures of purified minerals, it was established that freshly ground chalcopyrite displayed natural flotability in an oxidising environment and non-flotability in a reducing environment. No rational hypothesis to account for this behaviour has emerged. Grinding in an iron mill produced strongly reducing conditions and consequently suppressed flotation which was restored subsequently by raising the potential of the pulp either by aeration or by the addition of oxidants. The coarse particle sizes recovered more slowly than other fractions. The type and addition of frother had a pronouced effect on the natural flotability, but no proven effect on hydrophobicity. There is some evidence that whilst these observations apply to chalcopyrite from several sources when floated from mixtures with quartz, chalcopyrite in real ore samples does not necessarily show the same flotation behaviour.