Electro-generative mechanism for simultaneous leaching of pyrite and MnO2 in presence of A. ferrooxidans
(1. School of Chemistry and Chemical Engineering, Central South University,Changsha 410083, China; 2. School of Resources Processing and Bioengineering, Central South University, Changsha 410083,China; 3. Hunan Metallurgic Professional Technical College, Zhuzhou 412000, China )
Abstract: A dual cell system was used to study the output power, output voltage, galvanic polarization of anode and cathode, and the relationship between the electric quantity(Q) and some factors, such as the dissolved Fe2+ magnitude, the time in the electro- generative simultaneous leaching with bacteria(BEGSL) and without bacteria(EGSL). A three-electrode system was adopted to study their individual self-corrosion current, which was smaller compared with the galvanic current. The results show that the output power and voltage in BEGSL are higher than those in EGSL. The accumulated sulfur on the surface of sulfides produced in BEGSL can be oxidized by A. ferrooxidans, and the ratio of biologic electric quantity reaches 51.50% in 72 h. The first stage both in EGSL and in BEGSL is the dissolution of pyrite on the surface to ferrous ion and sulfur element, which was oxidized by A. ferrooxidans in the further procedure.
Key words: pyrite; MnO2; bio-oxidation; simultaneous leaching; electro-generation