Abstract: This study focused on the acidophilic microbial dissolution process of stibnite and investigated the effect of different proportions of pyrite on the interaction between acidophilic microorganisms and stibnite. The results showed that the Proteobacteria had the highest abundance at the phylum level, it was the main stibnite-tolerant bacterium.Acidithiobacillushad the highest level of abundance at the genus level, which was the representative dominant genus in acid mine environments. Additionally, SEM-EDS results showed that for microbial action systems with Sb2S3∶FeS21∶1 and 1∶2 , more corrosion pits and fine particles were found on the surface of mineral residues, and for the microbial action system with Sb2S3∶FeS21∶1, the interfacial reaction between stibnite and pyrite was stronger. XRD and XPS results indicated that the addition of pyrite could promote the oxidative decomposition of stibnite and sulfur oxidation by acidophilic microorganisms. Tafel polarization curves and EIS impedance results showed that when Sb2S3∶FeS2was 1∶1, the microbial system had the highest corrosion current density and the smallest charge-transfer impedance. The above results were of great significance for understanding the migration, transformation, and environmental fate of stibnite in antimony mining areas, and further promoting the development of antimony pollution control technologies.

Key words: stibnite, pyrite, acidophilic microorganisms, mineral-microbe interaction, microbial community