BIOLEACHING OF COPPER FROM COPPER SULFIDE MINERALS OF REKO DIQ DEPOSITS IN CHAGAI, BALOCHISTAN

Chagai, District of Balochistan, Pakistan is rich in minerals and has great diversity of mineral resources such as copper, Gold, Silver, molybdenum etc. Copper sulfide ore sample was obtained from Reko Diq deposit (Chagai District, Balochistan) Diq H- 4 Tanjeel area for experimental leaching studies. Concentration of copper by froth floatation or any other beneficiation technique is costly, very expensive, harmful to environment and not so efficient. Bioleaching concentration used in this study is considered one of the green methods adopting by many countries worldwide. During bioleaching process, mesophilic bacterial culture used in laboratory tests was sourced from the acid mine drainage of sulfur deposit collected from Koh-i-Sultan, Chagai District (Balochistan) and bioleaching was carried out by shake flasks at 30oC. Optimum growth occurs at pH 2.0-2.5 and 28-35 °C. Pyrite (FeS2) was also present in the ore simple. Calcite (CaCO3) was present as acid consuming gangue mineral in the ore. The presence of acidophilic bacteria in the acid mine water was observed under phase contrast microscope. Copper became soluble from ore owing to sulfuric acid in leaching process. Chemically controlled leach solution displayed 125.22 ppm copper during the similar leaching time. Leaching data exhibited that 87% copper became soluble from the ore owing to 30-days of acidophilic bacterial leaching. The rate of solubilization of copper from ore enhances due to the biological production of sulphuric acid by utilizing indigenous acidophilic bacteria present in pyrite, during leaching experiments. Keywords: Copper sulfide ore, acidophilic bacteria, bioleaching, metal extraction