Comparison of Microwave-Assisted and Conventional Leaching for Extraction of Copper from Chalcopyrite Concentrate

Kılıçarslan A., Önol K., Basit S., Sarıdede M. N.

World Academy of Science, Engineering and Technology International Journal of Materials and Metallurgical Engineering, vol.9, pp.1088-1091, 2015 (Conference Book)


Chalcopyrite (CuFeS2) is the most common primary 

mineral used for the commercial production of copper. The low 

dissolution efficiency of chalcopyrite in sulfate media has prevented 

an efficient industrial leaching of this mineral in sulfate media. Ferric 

ions, bacteria, oxygen and other oxidants have been used as oxidizing 

agents in the leaching of chalcopyrite in sulfate and chloride media 

under atmospheric or pressure leaching conditions. Two leaching 

methods were studied to evaluate chalcopyrite (CuFeS2) dissolution 

in acid media. First, the conventional oxidative acid leaching method 

was carried out using sulfuric acid (H2SO4) and potassium 

dichromate (K2


) as oxidant at atmospheric pressure. Second, 

microwave-assisted acid leaching was performed using the 

microwave accelerated reaction system (MARS) for same reaction 

media. Parameters affecting the copper extraction such as leaching 

time, leaching temperature, concentration of H



concentration of K2Cr2O7were investigated. The results of 

conventional acid leaching experiments were compared to the 

microwave leaching method. It was found that the copper extraction 

obtained under high temperature and high concentrations of oxidant 

with microwave leaching is higher than those obtained 

conventionally. 81% copper extraction was obtained by the 

conventional oxidative acid leaching method in 180 min, with the 

concentration of 0.3 mol/L K2

Cr2O7in 0.5M H


at 50 ºC, while 

93.5% copper extraction was obtained in 60 min with microwave 

leaching method under same conditions.