Insight into the Influence of Mineralogical Properties of Pristine Pyrite on Its Bioleaching with Thermophiles

ABSTRACT

To expound the relationship between bioleaching behaviors and mineralogical properties of pristine pyrite samples, chemical compositions, semiconductive properties, surface morphologies, and chemical species of synsedimentary pyrite (SSP) and mesothermal pyrite (MTP) were compared, accompanying with bioleaching behaviors analysis by three thermophiles. Mineralogical characterizations showed that both pyrites belonged to p-type semiconductors with an S/Fe ratio higher than 2, and the arsenic content in MTP was as high as 0.6%. The fractured surface of SSP had more kinks and steps, and higher concentrations of S^2- and oxides, as compared with that of MTP. Bioleaching results indicated that SSP was leached faster than MTP. The more kinked and stepped structures and the larger contents of S^2- and oxides on pyrite surfaces were the dominant reasons for the faster bioleaching kinetics of SSP. The high arsenic content in MTP limiting the cell growth was another cause for its slower leaching.

KEYWORDS:

• Synsedimentary pyrite
• mesothermal pyrite
• mineralogical properties
• thermophiles
• bioleaching

Acknowledgments

The authors would like to thank beamline BL14B1 (SSRF, China) for providing the beam time and helps during experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This study was supported by the Natural Science Basic Research Program of Shaanxi (No. 2020JQ-666) and the National Natural Science Foundation of China (No. 52004198, 51934009, 51374249).