| Abstrakt: |
Acidithiobacillus ferrooxidans is lithotrophic microorganism involved in many transformation and cyclic reactions of elements in nature, with an important role in biochemical cycles of sulfur and iron. Natural ability of this microorganism has been widely used by man in processes of metal exploitation. More precisely, to convert low-soluble metal compounds, mostly sulfides, into solutions. Practically, naturally occurring reactions have been directed and enhanced, in such a way to get useful metals, mostly from low-grade metal ores and waste materials. By the means of microbial leaching solution, in the case when the type of ore and the geological characteristics of the soil are suitable, it is possible to recover certain metals with minimum investment and threats to environment. In order to extract copper from ore dumps, microbial leaching has been conducted in laboratory using the culture of Acidithiobacillus ferrooxidans. Samples were taken from twelve different locations on Bor ore dumps. Leaching experiments were performed by the shake flask testing technique at 28°C, during two-week period. Parameters, like solid-liquid ratio, number of bacteria, rate of leaching, physical and chemical characteristics of ore, were determined. Obtained results show 7.5-fold higher copper leaching efficiency in the suspension with Acidithiobacillus ferrooxidans, then in control suspension. Microbial leaching of low-grade ores and ore dumps plays very important role in the concept of environmental protection, because it allows use of relatively simple technology to control and redirect uncontrolled loss of metals into the soil and water-streams. [ABSTRACT FROM AUTHOR] |
