THE OXIDATION OF GALENA USING THIOBACILLUS-FERROOXIDANS

The leaching behavior of galena in the presence of Thiobacillus ferrooxidans was investigated. In acidic media, at about pH 2.8, galena was oxidized to form lead sulfate, It was observed that the addition of 0.4% ferrous sulfate increased the initial rate of galena leaching and a higher concentration of iron did not appear to inhibit the rate of reaction. The final amount of galena oxidized, approximately 92%, was found to be independent of various leaching conditions applied. The physiological behavior of bacteria during the galena leaching has also been studied by monitoring the enzyme activities of sulfide oxidase in the cell fractions of the sphaeroplast and cytoplasm. It was observed that the sulfide oxidase activity was present in the cytoplasm and there was a periplasmic protein unique to galena oxidation.