Continuous Tank Bioleaching of Mine Tailings by a Mesophilic Bacterial Culture

摘要

The aim of the present study is to develop a continuous bioleaching process for the detoxification of mine tailings with a high amount of arsenic. We used a mesophilic bacterial consortium, previously adapted to high solid and heavy metals concentrations, mainly composed of L. Ferriphilum, A. cupricumalans, F acidophilum, and A. ferrooxidans. Sensitivity analyses and optimization tests for various operating parameters {e.g., agitation speed, solid concentration, oxygen and carbon dioxide requirement, nutrient requirement, residence time, particle size distribution) were carried out in a laboratory scale unit composed of 3 reactors connected in series. To understand and assess the performance of the system, the following analyses were performed during the experiments: arsenic leaching efficiency, ferrous to ferric oxidation rates, pH and redox potential. When the edition of this abstract closed, 40% of extraction efficiency was achieved during a preliminary run in a prototype laboratory unit composed of 2 1-L operating volume in series.