Enhanced Column Bioleaching of Copper Sulfides by Forced Aeration

To assess the effects of forced aeration on leaching dynamics of sulfides, five sets of column bioleaching of copper sulfides using Acidithiobacillus ferrooxidans were conducted when the aeration rates ranged from 0 to 150 L/h. The experimental results show that forced aeration can ameliorate the porosity and flow rates throughout the heap, and improve the bacterial concentration and oxidative ability. Forced aeration at the column bottom can enhance the interactions of air, flow and particles, and then facilitate the heap porosity and connectivity. The oxidant Fe3+ concentrations are proportional to the aeration rates, and lead to an accelerating dissolution rate of sulfides. In addition, the bacterial concentration, oxidative ability and Fe3+ concentration are susceptible to aeration rates, and the forced aeration remarkably enhances the bioleaching when aeration rates are higher than 60 L/h compare to those with none or slight aeration.