EFFICIENCY INCREASE IN MINING OF HIGH-GRADE IRON ORE DEPOSITS WITH SOFT ORES

The article provides a geomechanical substantiation of the mass around the preparatory workings of the Yakovlevo deposit of high-grade iron ores using the finite element method implemented in the Simulia Abaqus software package. The simulation considered two schemes of transition from a layered system to a chamber one with enlarged geometric parameters of polygonal mine workings. The results of numerical simulation of the stress-strain state are obtained for various types of ores and are represented in the diagrams of the distribution of the main normal maximum stresses and configurations of the limiting condition zones of the mass around the workings/ chambers at various stages of mining. The geomechanical justification of the safe parameters of the polygonal-shaped chambers confirmed the possibility of switching to the mining of martite and hematite-martitic iron ore reserves by an option of a layer system with larger chambers. The use of the obtained results on high-grade iron ore deposits with soft ores will increase the productivity, efficiency, and safety of mining