Microbially-Induced Corrosion of Structural Materials in Underground Workings of the Yakovlev’s Mine (Kursk Magnetic Anomaly, Russia)

Role of biocorrosion in the early fracture of underground metal structures at the Yakovlev’s mine (Kursk Magnetic Anomaly) of high-grade iron ores (HGIO) is analysed based on integrated study including microbiological methods of investigation. Major natural and technogenic sources of microorganisms input into the iron ore body are specified. Underground microbiota of the Yakovlev’s mine along with factors promoting its intensification are studied. Particular attention is paid to favorable conditions existing down the mine that facilitate electrochemical and biochemical corrosion of ferrous metals. During the investigation a wide range of aerobic and anaerobic microorganisms including various species of bacteria, micromycetes and actinomycetes was encountered. Inoculated cultures were frequently characterized by abnormal microbial counts exceeding 106 cells per 1 g of dispersed iron ore. Special microbiological monitoring aimed to study in situ dynamics of deteriorating test metal coupons placed in the aggressive environment of moistened HGIO was conducted. Acquired results are suggesting the necessity of due account of microbial corrosion while assessing safety of mining operations and ensuring stability of the metal arch support.