The Relationship between Metabolic Pathways of Bacteria and Pyrrhotite Bioleaching Behavior

Abstract:

The effect of Sulfobacillus thermosulfidooxidans, cultured respectively in the substratum containing ferrous ion or solid elemental sulfur in a long term, on the leaching behavior of pyrrhotite was revealed through leaching test and surface analysis of pyrrhotite leaching residues using XRD and SEM. It was demonstrated that there was significant difference in growth characteristic of S. thermosulfidooxidans, the leaching behavior and surface products of pyrrhotite when pyrrhotite bioleaching was conducted using S. thermosulfidooxidans cultured in different mediums, and it suggested that the difference was chiefly due to different energy metabolism pathways. The pyrrhotite leaching behavior using S. thermosulfidooxidans grown on ferrous ion in a long term was similar to that in the sterile acidic system, and only leaching yield was slightly improved. This was attributed to the ability to oxidize sulfur of S. thermosulfidooxidans was weakened and thus the effect of the generated sulfur could not be eliminated, which leads to low iron extraction and low S. thermosulfidooxidans reproduced ability for lack of growth energy. In the case of S. thermosulfidooxidans cultured in medium containing sulfur, The ability to oxidize sulfur was enhanced, the bacterium grew rapidly in the mid-term of leaching, which weakened the suppressing effect of sulfur film and improved significantly pyrrhotite leaching. However, a large number of jarosite was generated owing to the accumulation of ferric ions with the bioleaching processing, and the formed wrapping layer by jarosite and minor sulfur on mineral surface suppressed further leaching of pyrrhotite.

• Periodical: Advanced Materials Research (Volume 1130)
• Pages: 175-178
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1130.175
• Online since: November 2015
• Authors: Guo Hua Gu, Hui Sha Yang, Chong Qing Wang, Xiong Yi Xu
• Keywords: Bioleaching, Energy Sources, Pyrrhotite, Sulfobacillus thermosulfidooxidans

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