Final Project Completion Report For CORE-0020 Project (under CSIR's Tenth Five Year Plan: 2002-2007)

The continued depletion of high grade ore and growing awareness of environmental problems associated with traditional methods have led researchers to explore alternate, efficient and less polluting biological methods in copper and uranium extraction, processing and waste water treatments. Pyrometallurgical and hydrometallurgical methods have some disadvantages such as unsuitability to low grade and complex ores, involvement of high cost and increase in pollution load. The alternate processing option is expected to conform to high efficiency, relatively less expensive methodology involving low energy consumption and must be environmentally benign. Bio-leaching is considered an appropriate processing technology to address to several problems mentioned above. The uranium solubilising and accumulating properties of microorganisms that could catalyze the oxidation of the metal may be exploited to ease the supply of this strategic metal for the country. In fact, industrial-scale bioleaching of uranium is carried out by spraying stope walls with acid mine drainage and the in-situ irrigation of fractured underground ore in the mine. Similarly, copper bio-dissolution from its low-grade ore has inherent potential since no other processes are suitable for such deposits. Besides its industrial application to material supply, microbial leaching has some potential for remediation of mining sites, treatment of waste and detoxification of sewage sludge. Based on this, a collaborative network project was conceived for possible funding in a network mode by involving CSIR laboratories in the country under Tenth Five Year Plan. The amenability of the low-index ores of copper and uranium was tested using Acidithiobacillus ferrooxidans isolated from source mine water and results are presented in this report.