SUBSTANTIATION OF RATIONAL TECHNOLOGIES FOR CARRYING OUT PREPARATORY-THROWED RAIS IN THE MINING BLOCKS OF IRON MINES, WHICH ENSURE INCREASED STABILITY OF THE MASSIF EXPOSURES

Purpose. Improving the efficiency and safety of mining operations in the process of preparatory-rifled risers, through the use of rational technological schemes of borehole hydraulic technology. Methods. Analysis of literary sources, design documentation and practice of developing mineral deposits by underground method. Designing a technological scheme for borehole hydraulic technology for preparatory-rifled risers. Technical and economic comparison of the developed technological schemes for conducting preparatory-rifled risers. Results. The results of the study were proposals for improving and increasing the efficiency of preparatory-rifled risers in the process of underground mining of rich iron ore deposits by using safe technological schemes of borehole hydraulic technology. The main areas of mining and geological conditions for the rational use of specific technologies for risers are determined. Scientific novelty. The dependences of the cost of carrying out 1 m3 of preparatory-rifled riser in different ways on its length are obtained. It has been established that for the effective destruction of low-strength martite ores by hydraulic monitors, the dynamic pressure of water jets should be 0.1–0.2 of the uniaxial compression strength of the massif. Practical implication. A technological scheme has been developed for conducting preparatory-rifled risers using borehole hydraulic technology, which allows for low-operation, flow and safety of mining operations, flexibility in controlling the concentration and volume of work, good compatibility with traditional mining technologies, as well as preliminary enrichment in the converter or open-hearth production of high-quality steel grades. Efficiency is ensured by the simplification of tunneling technology, high penetration rate, energy and material savings.