The Leaching Behavior of Copper from Chalcopyrite Tailings in the Presence of Silver Ion in Bioleaching System

The objective of this research was to investigate the effect of silver ion on the bioleaching behavior of copper from chalcopyrite tailings. We selected A.t ferrooxidans as bioleaching bacteria and copper-containing tailings as experiment subject in our research. Apart from concentrations of silver ions, the conditions for the leaching experiments were identical: pulp density 150 g/L, bacterial inoculation amount around 10(7) cells/mL, pH at 2.0, leaching temperature 30 degrees C rotation speed 150 r/min. The results showed that 82% copper contained in ore tailing was dissolved into the leaching solution when the silver ion concentration was 0.01 g/L, while only 13% and 35% copper dissolved when the silver ion was 0.05 g/L of concentration and at its absence, respectively. This outcome indicated that the presence of silver ion, as well as its concentrations, exerted a significant influence on bioleaching behavior of copper minerals, and low concentration of silver ion could contribute to leaching.