Engineering-geological and geo-ecological assessment of the stability of the rich iron ores of the Yakovlevsky mine (KMA)

Abstract

The Yakovlevsky deposit of the Kursk Magnetic Anomaly (KMA) is characterized with large reserves and high grades of iron ores which are products of chemical weathering of ferruginous quartzites in Pre-Paleozoic period. High-grade iron ores (HGIO) are non-compacted variations with high porosity and even macroporosity. Their occurrence depth is over 500 m. The article analyses granulometric composition, physical properties and strength parameters of various highgrade iron ore types. Acceptable level of hydrodynamic pressure is calculated with the view of the pillar width, which is equal to 53 m, and various widths of individual working spans. Forecast time of underground waters penetration from the overlying Low Carboniferous aquifer horizon to the - 370 m horizon is calculated. Conclusions are made on negative impact of underground waters penetration which leads to secondary watering of the high-grade iron ores, a sharp decrease in their durability that creates preconditions for inrush formation.