World Academy of Science, Engineering and Technology International Journal of Materials and Metallurgical Engineering, cilt.9, ss.1088-1091, 2015 (Düzenli olarak gerçekleştirilen hakemli kongrenin bildiri kitabı)
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
Cr2O7
) 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
2SO4
and
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
2SO4
at 50 ºC, while
93.5% copper extraction was obtained in 60 min with microwave
leaching method under same conditions.