Extraction of copper from Seruwila copper magnetite deposit

Abstract

Seruwila Copper Magnetite deposit remains unextracted, although proper exploration work have been carried out. A XRF characterization was conducted in the laboratory for the systematically collected field ore sample. It was confirmed that 0.6% Cu and 20-50% Fe are available in the sample on average. Raw ore samples followed a comminution process where the particle size was reduced up to 75μm. Sulfuric acid was used as the leaching medium. Particles below the size of 75μm gave optimum leaching efficiency. Leaching efficiency could be improved with increasing temperatures and acid concentrations. Optimum solid/liquid ratio was determined to be in the range 20/125 – 20/150 (g/ml) for leaching. Selective extraction of Cu cations from the leachate solution was successfully conducted using an Ammonia solution. Formed complex solution was filtered and treated with concentrated Sulfuric acid to prepare an electrolyte solution. Elemental analysis of the deposited layer from electrowinning the above solution gave 76.62% Cu along with current efficiency of 72% and power consumption of 1023.5 kWh/t. It was concluded that this methodology is economically feasible when compared with electrowinning the leachate directly, which resulted only 62.88% Cu with comparatively lower current efficiency of 50.95% and higher power consumption of 3097 kWh/t.