Insights into the relation between adhesion force and chalcopyrite-bioleaching by Acidithiobacillus ferrooxidans.

Abstract This paper presents a study on the relation between bacterial adhesion force and bioleaching rate of chalcopyrite, which sheds light on the influence of interfacial interaction on bioleaching behavior. In our research, Acidithiobacillus ferrooxidan s ( A . ferrooxidan s) were adapted to grow with FeSO 4 ·7H 2 O, element sulfur or chalcopyrite. Then, surface properties of Acidithiobacillus ferrooxidans and chalcopyrite were analyzed by contact angle, zeta potential and Fourier transform infrared spectroscopy (FTIR). Adhesion force between bacteria and chalcopyrite was measured by atomic force microscopy (AFM). Attachment and bioleaching behaviors were also monitored. The results showed that A . ferrooxidan s adapted with chalcopyrite exhibited the strongest adhesion force to chalcopyrite and the highest bioleaching rate. Culture adapted with sulfur bacteria took second place and FeSO 4 ·7H 2 O-adapted bacteria were the lowest. Bioleaching rate and bacterial attachment capacity were positively related to bacterial adhesion force, which is affected by the nature of energy source. According to this work, the attachment of bacteria to chalcopyrite surface is one of the most important aspects that influence the bioleaching process of chalcopyrite.