Bioleaching of copper and other metals from low-grade oxidized mining ores by Aspergillus niger

• Published in: Journal of chemical technology and biotechnology (1986) 2003-05, Vol.78 (5), p.497-503
• Main Authors: Mulligan, Catherine N, Kamali, Mahtab
• Format: Article
• Language: English
• Subjects: Aspergillus niger; Biohydrometallurgy. Microbial leaching; bioleaching; Biological and medical sciences; Biotechnology; citric acid; copper; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; mining ore; organic acids; Solanum tuberosum
• ISSN: 0268-2575; 1097-4660
• DOI: 10.1002/jctb.830

A study was initiated to determine the feasibility of using the fungus Aspergillus niger for bioleaching metals from oxide low‐grade ore. Large quantities of the metals are embodied in the low‐grade ores and mining residues that can be recovered. Presently available techniques (pyrometallurgical and hydrometallurgical) are expensive or may have a negative impact on the environment. An oxidized mining ore containing mainly copper (7245 mg kg−1 residue) was studied. In this study, the fungus A niger produced a variety of organic acids. Addition of small quantities of sulfuric acid enhanced the organic acids, efficiency. Various agricultural wastes were evaluated as substrates and a maximum solubilization of 68% for copper for a medium containing potato peels was achieved. In conclusion, leaching of copper from a mining ore is technically feasible using A niger. Further research must be performed to increase the rate of copper removal. Copyright © 2003 Society of Chemical Industry