AP19676884 "Development of effective methods for crushing rock mass during mining of ore from a complex-structured array by controlling the parameters of the explosion energy"

Relevance

The development of deposits with highly fractured and complex-structured massifs presents serious engineering and technical difficulties. Unstable physical and mechanical properties of rocks and a high degree of fracturing significantly reduce the effectiveness of traditional drilling and blasting technologies. In this regard, it is important to develop scientifically sound methods of explosive energy management that ensure stable destruction of the array, increase productivity and reduce production costs.

Purpose

The aim of the work for 2024 is to develop methods for controlling the energy of an explosion and the parameters of drilling and blasting operations for the destruction of complex-structured and highly fractured rock formations based on theoretical and experimental studies, modeling gas-dynamic processes and optimizing the design of explosive charges.

Expected and achieved results

It has been established that fractures in fractured massifs are initiated by stretching waves, and when a charge detonates, the explosion energy is evenly distributed in all directions, but outside the fracture zones, the voltage decreases rapidly. To calculate pressure and stresses, a model with equivalent resultant forces directed along four axes to the center of gravity of the charge has been developed. Modeling of gas-dynamic processes in the charging chamber has shown that the use of gas-dynamic downhole in conditions of destruction of complex-structured highly fractured arrays ensures a delay of detonation products by 10-15 ms, which, in turn, leads to prolonged exposure to increased pressure on the borehole walls. It has been found that the size of fracture zones increases with increasing charge length, which must be taken into account when designing explosive circuits, especially in fractured rocks, where the size and shape of fracture zones may vary depending on geological conditions. Studies have shown that a charge length equal to 0.75 of the well depth or 0.85 of the ledge height is the most effective for achieving high-quality crushing and maximum fracture volume. Based on the results obtained, the relationship between the radii of the fracture zones and the magnitude of the destructive stresses was established, and an empirical formula for determining the fracture radius was proposed.