Flotation of an Oxidized Copper Sulfide Ore

摘要

This paper presents the results of the characterization and processing of the Hofrat En Nahas copper sulfide ore from Sudan (Southwest of Darfur). Mineralogical examinations indicated that chalcopyrite is the main valuable copper mineral present in this ore. The associated gangue minerals include pyrite, feldspar, quartz and calcite. Furthermore, the mineralogical investigation revealed that the chalcopyrite mineral surface has been subjected to oxidation and/or alteration. Microscopic examination and grain counting of the size fractions indicated that the degree of liberation of the copper minerals was obtained at about 150 μm. A sulfidization-flotation method was used, on a laboratory scale, to investigate the amenability of this ore to be concentrated. Promising results were obtained at pH 12, 16 g/Mg potassium amyl xanthate collector, 16 g/Mg sodium sulfide as sulfidizing agent, and 20% solids in the pulp using pine oil as a frother. From a flotation feed assaying 2.7% Cu, a copper concentrate assaying about 23.5% Cu at a recovery of 91.5% was obtained in only one roughing and one cleaning stages.