Abstract
— Chalcopyrite is the primary source of low-grade copper ore, it is one of the minerals which occur in large amounts and plays an important role in industry, as it makes up to 70% of copper deposits in the world. The formation of passive surface layers during leaching of chalcopyrite impacts recovery rates of copper, making determination of rate-limiting factors an important step for process optimization. The chalcopyrite concentrate was roasted at a temperature of 600°C to convert the concentrate from sulfide to oxide or sulfates. The roasted concentrate was leached using sulfuric acid and acetic acid separately, varying temperature and pH of the acids. pH was optimized first thenòptimum pH was used to determine effects of temperature and the leachate was collected after every 2 hours up to 8 hours and analyzed using atomic absorption spectroscopy. Results indicate that roasting process converts copper sulfide in chalcopyrite into copper sulfate (chalcocyanite) and oxides. Optimal copper recovery during leaching is achieved under highly acidic conditions (low pH) and elevated temperatures of up to 55°C, which promote dissolution and reaction kinetics. Sulfuric acid proves far more effective than acetic acid due to its stronger acidic nature, resulting in a faster reaction rate and lower activation energy.