Electrochemical behavior of chalcopyrite in presence of Thiobacillus ferrooxidans
(Department of Mineral Engineering, Central South University of Technology, Changsha410083,P.R.China)
Abstract: The electrochemical behavior of chalcopyrite both in the absence and presence of bacteria(Thiobacillus ferrooxidans) in acid solution was studied by using various electrochemical measurement methods. It was shown from the results of the electrochemical measurements that the rest potential E r is 0.255 V (vs SCE) in uninoculated acid solution, but is up to 0.308 V in inoculated solution, and the corrosion characteristic of chalcopyirte is pitting corrosion. In addition, it is first found that the pitting potential E b of chalcopyrite electrode is all 0.635 V in both uninoculated and inoculated cases. This means that the presence of Thiobacillus ferrooxidans in the solution has no effect on the pitting potential. But the pitting current has been enhanced from 0.05 mA/cm2 in uninoculated case to 0.51 mA/cm2 in inoculated case, and the corrosion rate of chalcopyrite electrode in the later case has increased 10 times.
Key words: chalcopyrite； bacteria； rest potential； pitting potential