Regular Article

Effects of Acidithiobacillus ferrooxidans and Fe(III) on pyrite–pyrolusite bioleaching process

¹ School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
² State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

^⁎ e-mail: hrli@home.ipe.ac.cn

Received: 22 June 2016
Received in final form: 5 October 2016
Accepted: 16 March 2017

Abstract

The beneficial effects of Acidithiobacillus ferrooxidans and/or Fe(III) on manganese bioleaching from a low-grade manganese ore were confirmed. The results showed that the rate of manganese bioleaching increases with the amount of A. ferrooxidans and/or Fe(III). With the presence of Fe(III) and A. ferrooxidans the average initial leaching rate increased from 0.06 to 0.15 g/(L h). Cyclic voltammetry analysis showed that the presence of A. ferrooxidans and/or Fe(III) generate obvious redox potential polarization in the solution. Fe(III) reduced the potential difference between anode and cathode of pyrite and promoted the positive cathodic polarization of pyrolusite at 0.2 V. In the process of pyrite oxidation A. ferrooxidans accelerated the generation and transfer of electron.