Abstract

The chemical composition and dust formation during the oxidation of copper concentrate particles under suspension-smelting conditions were investigated. The effects of initial particle size and oxygen concentration in the process gas on the particle composition, morphology, and mineralogy of the reacted particles along a laminar-flow reactor were tested. The chemical composition of the reacted particles was determined by atomic absorption spectroscopy. The mineralogy was determined by X-ray diffraction and QEMSCAN® techniques, the latter of which involves scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. The experimental data indicated that the smaller the size fraction in the feed, the higher the extent of oxidation. The QEMSCAN® micrographs in general agree with a reaction mechanism involving expansion and further fragmentation of the particles during flight. The extent at which both phenomena occurred was dependent upon the initial particle size and residence time of the particles in the reactor.