The article provides a comprehensive analysis of usingTNT-free explosives (E) in the iron ore mining sector in Ukraine. It delves into thedevelopment and application of a specific type of emulsion explosive known as "Ukrainit," which is free from TNT, with the objective of its adoption in underground iron ore mining operations. Pilot blasting activities were carried out at PJSC "ZaporizhzhiaIron Ore Plant" (PJSC "ZIOP"), selected for its state-of-the-art equipment and advanced ore extraction technology.Through examination of ground-level concentrations of environmentally hazardous substances, the study revealed that the highest levels of carbon monoxide, nitrogen oxide, and dioxide were observed in 2008 when underground mining operations exclusively used100% TNT-containing E. However, by the year 2020, a situation changedwith implementation of a blend comprising 78% "Ukrainit" type EE and 22% TNT-containing explosives, resulting in anotable decrease in the maximum concentrations of environmentally hazardous substances compared to 2008. Specifically, carbon monoxide leveldecreased by 5.0–5.5 times, while nitrogen oxide and dioxide levels decreased by 1.2–1.3 times.Furthermore, useof "Ukrainit" type EE at PJSC "ZIOP" led to a 1.5 times decrease in the environmental hazard index on average (reduced to 36%) compared to the usage of TNT-containing E. These findings underscore the significant environmental benefits associated with the adoption of TNT-free explosives in iron ore mining operations, particularly in mitigating the release of harmful substances and reducing environmental risks.
Laboratory and industrial studies have established the total impact of environmentally hazardous substances, taking into account the distance from the source of emissions and the specific consumption of explosives. With the help of physicochemical analysis and biological testing, the dependence of the change in the conditional indicator of damage to bioindicators with an increase in the distance from the source of emission and the specific annual consumption of explosives was revealed. A methodology for calculating the environmental assessment of the state of atmospheric air around the mine ventilation shaft has been developed. The exponential dependence of the influence of surface concentrations of environmentally hazardous substances on the damage of bioindicators at the cellular and organismic levels has been established, which makes it possible to assess the state of atmospheric air at industrial sites of iron ore mines. The proposed technology of sand drilling, which involves the use of emulsion explosives in mining ore deposits in chamber development systems will reduce emissions of environmentally hazardous substances into the atmosphere and increase the level of environmental safety of iron ore mines.
Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, their structural composition, fracturing and compaction under the action of rock pressure, were developed. Based on the change in the stress-strain state of the rock mass under the action of the explosion, numerical modelling of the radii of the zones of crumpling, intensive fragmentation and fracturing was performed using the finite element method. According to the simulation results, the power dependence of the change in the radii of the crumpling and fragmentation zones of the rock mass was determined depending on the diameter of the charging cavity, the pressure of the explosion products, and the limit of rock compressive strength. By comparing the results of analytical and numerical modelling for rigid boundary conditions of a homogeneous non-cracked rock mass, the difference in the values of the radii of the defined zones was established as being 4, 8 and 6%, respectively. The resulting analytical models of the radii of crushing zones, intensive fragmentation and fracturing increase the accuracy of estimating the parameters of rock mass destruction by explosion by up to 50% and improve the parameters of drilling and blasting operations when carrying out mining operations, special purpose cavities and rocking of the rock mass.
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