A device to intensify preliminary softening of frozen overburden at open-pits of the permafrost zone

The main challenges in mining frozen grounds in winter time are related to the topmost layer, which softening can provide optimal conditions for its removal. The article describes the developed patented device, which can be used in the openpit mining of mineral deposits in the permafrost zone, providing intensification of preliminary blastless softening of frozen overburden using surface-active substances (surfactants). It is emphasized that the technical task of the device is to maintain a constant level of solution in the boreholes without its overflow, ensuring continuous penetration of the surfactant solution into the cracks and pores of the ground mass due to the hydrostatic pressure of the surfactant solution itself. For this purpose, the device is fitted with a perforated dispenser to ensure a uniform, continuous supply of the surfactant solution. A dedicated hole or valve should be provided in the upper part of the shell to balance the pressure inside the tank with atmospheric pressure, and its lower part is covered with drilling fines to provide its vertical stability. An insufficient degree of implementing the surfactantbased methods of rock softening is noted, as well as the fact that the proposed device will cause a decrease in their strength and deformation properties and will allow, within certain limits, to control the state and properties of the mined rock mass in open-pit mines in the northern regions of the Russian Federation.