ABSTRACT A low-grade ore containing ~0.3% Cu, remains unutilized for want of a viable process at Malanjkhand Copper Project (MCP), India in which copper is present as chalcopyrite associated with pyrite in quartz veins and granitic rocks. In order to extract copper from this material, bioleaching has been attempted on bench scale using Acidithiobacillus fer-rooxidans (A. ferrooxidans) isolated from the native mine water. The enriched culture containing A. ferrooxidans when adapted to the ore and employed for the bioleaching at 5% (w/v) pulp density, pH 2.0 and 25°C with three particle sizes viz.150 -76 μm, 76 - 50 μm and <50 μm, resulted in recovery of 38.31%, 29.68% and 47.5% Cu respectively with a maximum rise in redox potential (ESCE) from 530 to 654 mV in 35 days. Under similar conditions, the unadapted strains gave a recovery of 44.0% for <50 μm size particles with a rise in ESCE from 525 to 650 mV. On using unadapted bacte-rial culture directly in shake flask at pH 2.0 and 35°C temperature and 5% (w/v) pulp density (PD) for <50 μm size par-ticles, 72% Cu bio-dissolution was achieved in 35 days. Copper biorecovery increased to 75.3% under similar condi-tions with a rise in bacterial count from 1 × 107 cells/mL to 1.13 × 109 cells/mL in 35 days. The higher bio-recovery of copper with the adapted bacterial culture may be attributed to the improved iron oxidation (Fe2+ to Fe3+) exhibiting higher ESCE as compared to that of unadapted strains.
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Abhilash, .. , D. Mehta, K. and D. Pandey, B. (2012) Efficacy of Bacterial Adaptation on Copper Biodissolution from a Low Grade Chalcopyrite Ore by A. ferrooxidans. International Journal of Nonferrous Metallurgy, 1, 1-7. doi: 10.4236/ijnm.2012.11001.
 A. E. Troma, “New Trends in Biohydrometallurgy,” In: R. W. Smith and M. Misra, Eds., Mineral Bioprocesing, The Minerals, Metals & Materials Society, Pennsylvania, 1991, p. 43.
A. R. Colmer and M. E. Hinkle, “The Role of Microor-ganisms in Acid Mine Drainage,” Science, Vol. 106, No. 2751, 1947, pp. 253-256. doi:10.1126/science.106.2751.253
G. Rossi, “Biohydrometallurgy,” McGraw-Hill Book Company, Hamburg, 1990.
K. A. Natarajan, “Electrochemical Aspects of Bioleach-ing of Base-Metal Sulphides,” In: H. L. Ehrlich and C. L. Brierley, Eds., Microbial Mineral Recovery, McGraw- Hill Book Company, New York, 1990, p. 79.
A. Das, J. M. Modak and K. A. Natarajan, “Studies on Multi-Metal Ion Tolerance of Thiobacillus Ferrooxidans,” Minerals Engineering, Vol. 10, No. 7, 1997, pp. 743-749. doi:10.1016/S0892-6875(97)00052-6
M. P. Silverman, “Mechanism of Bacterial Pyrite Oxida-tion,” Journal of Bacteriology, Vol. 94, 1967, pp. 1046-1051.
L. A. Brickett, R. W. Hammack and H. M. Edenborn, “Comparison of Methods Used to Inhibit Bacterial Activ-ity in Sulfide Ore Bioleaching Studies,” Hydrometallurgy, Vol. 39, No. 1-3, 1995, pp. 293-305. doi:10.1016/0304-386X(95)00043-G
A. Schippers and W. Sand, “Bacterial Leaching of Metal Sulfides Proceeds by Two Indirect Mechanisms via Thi-osulfate or via Polysulfides and Sulfur,” Applied and En-vironmental Microbiology, Vol. 65, No. 1, 1999, pp. 319- 321.
L. Patnaik, R. N. Kar and L. B. Sukla, ”Infuluence of pH on Bioleaching of Copper and Zinc from Complex Sulphide Concentrate Using Thiobacillus Ferrooxidans,” Transactions of the Indian Institute of Metals, Vol. 54, No. 4, 2001, pp. 139-144.
G. S. Hansford and T. Vargas, “Chemical and Electro- chemical Basis of Bioleaching Processes,” Hydrometal-lurgy, Vol. 59, No. 2-3, 2001, pp. 135-145. doi:10.1016/S0304-386X(00)00166-3
W. Sand, T. J. Gehrke and A. Schippers, “(Bio)Chemistry of Bacterial Leaching—Direct vs. Indirect Bioleaching,” Hydrometallurgy, Vol. 59, No. 2-3, 2001, pp. 159-175. doi:10.1016/S0304-386X(00)00180-8
A. D. Agate, K. M. Paknikar and N. J. Khinvasara, “Scale-Up Leaching of Malanjkhand Copper Ores—A Case Study,” In: J. Salley, R. G. L. Mcready and P. L. Wichlaez, Eds., Biohydrometallurgy, CANMET, 1989, p. 577.
D. Pradhan, S. Pal, L. B. Sukla, G. Roy Choudhary and T. Das, “Bioleaching of Low Grade Copper Ore Using In-digenous Microorganism,” Indian Journal of Chemical Technology, Vol. 15, 2008, pp. 558-592.
S. C. Pal, K. D. Mehta, B. D. Pandey and T. R. Mank- hand, “Biomineral Processing for Extraction of Copper Metal from Lean Ore of Malanjkhand Copper Project,” International Conference on Emerging Trends in Mineral Processing and Extractive Metallurgy (ICME-2005), Bhubaneswar, India, pp. 246-255.
F. Habashi, “Chalcopyrite: Its Chemistry and Metallurgy,” McGraw-Hill, New York, 1978.
D. Bevilaqua, A. L. L. C. Leite, O. Garcia Jr. and O. H. Tuovinen, “Oxidation of Chalcopyrite by Acidithiobaci- llus ferrooxidans and Acidithiobacillus thiooxidans in Shake Flasks,” Process Biochemistry, Vol. 38, No. 4, 2002, pp. 587-592. doi:10.1016/S0032-9592(02)00169-3
M. B. Stott, H. R. Watling, P. D. Franzmann and D. Sutton, “The Role of Iron-Hydroxy Precipitates in the Passivation of Chalcopyrite during Bioleaching,” Mine- rals Engineering, Vol. 13, No. 10, 2000, pp. 1117-1127. doi:10.1016/S0892-6875(00)00095-9
Y. Rodriguez, A. Ballester, M. L. Blazquez, F. Gonzalez and J. A. Muňoz, “New Information on the Chalcopyrite Bioleaching Mechanism at Low and High Temperature,” Hydrometallurgy, Vol. 71, No. 1-2, 2003, pp. 47-56. doi:10.1016/S0304-386X(03)00173-7