Survey of Thiobacillus ferrooxidans in solubilization of copper sulphide ores

Survey of several mining operations in Australia revealed the presence of typical Thiobacillus ferroxidans bacteria in the leaching solutions. Using a serial dilution cultural method and employing a liquid iron medium, the bacterial density was estimated to be about 100 million cells/ml. In leaching operations, these organisms increased in numbers from the oxidation ponds to the final pond with a concomitant decrease in ferrous iron content. The data also showed that a large number of bacteria were present in water from deep mining operations. Laboratory studies on leaching of copper ores showed that microbial activity was mainly responsible for rapid solubilization and that a relationship existed between the environmental factors such as temperatures, pH of the leaching effluent water and the bacterial count. (Dr. A.D. Agate, Prof. And Head of the Microbiology Department, MES's Abasaheb Garware College, Karve Road, Poona-4)