Quartz mineral bioleaching by Acidithiobacillus ferrooxidans in gravity column reactor

Quartz mineral bioleaching by Acidithiobacillus ferrooxidans in gravity column reactor. Bioleaching is the process by which copper is extracted from low-sulfur minerals using microorganisms. However, chemical leaching is preferably applied to extract copper from oxidized or mixed minerals, without reports of application of microorganisms in this operation. In this work, we investigated the presence of Acidithiobacillus ferrooxidans in 9K medium and quartz mineral, with quartz sandstone, cuprite and pyrite at different particle sizes. It was found that at 24 days of the chemical leaching process 86[%] of copper was recovered when bacteria were included and only 54[%] recovered without them. The highest copper recovery in both processes was obtained in the fol-lowing order according to the particle size: 9.5 mm > 12.5 mm > 19.05 mm. The application of bacterial cells to chemical leaching processes with oxidized copper minerals including quartz and A. ferrooxidans cells increases copper recovery while the mineral particle size is lower. This technology may be used for mining companies that are still performing chemical leaching and may include in the operation the addition of microorganisms to increase copper recovery from mineral sulfides including quartz.