Chalcopyrite Leaching in Ammonia-Ammonium Chloride Solutions: Insight into the Dissolution Kinetic Studies

Abstract

The hydrometallurgical method for processing chalcopyrite ore has gained enormous attention due to the environmental problems emanated by the conventional pyrometallurgical route. Here, hydrometallurgy is considered an alternative that may be more of low-cost and environmentally friendly. Thus, alkaline leaching has been considered an effective, efficient, and acceptable leachant for chalcopyrite ore dissolution. The dissolution behaviour of copper from low-grade chalcopyrite mineral was examined in an ammonia-ammonium chloride media. However, the influence of experimental conditions including alkali concentration, reaction temperature, and particle size was considered. At optimized leaching conditions (o.4 mol/L NH3-NH4Cl; 75 °C; 43 μm), 81.1% dissolution efficiency was achieved within 120 minutes. The dissolution mechanism with estimated activation energy (Ea)of 29.95 kJ/mol is by the proposed diffusion control mechanism. Hence, the dissolution rate was affirmed by analyzing the raw ore and un-leached residue using XRD and SEM-EDS analyses for possible industrial utilities.