Results of studies of hardening heap of charges of explosive

Abstract

Purpose. Investigation of a new hardening composition of the heel of a blast-hole charge of explosives, which improves the quality of the explosion, reduces the concentration of fine dust and provides an overall reduction in the dust content of the mine atmosphere, and, thereby, improves working conditions and work safety. The methodology. The studies were carried out in laboratory conditions on volumetric models using the method of accelerated photo-registration of the process in conjunction with polarization-optical studies of stresses, respectively, with approved methods of destruction of solid media by explosion. Research results. In volumetric models made of organic glass, when they were destroyed by an explosion of an explosive charge of different design, the appearance and propagation of stress waves was recorded using a special stand with a photo-recording device, a flash lamp, and lens systems. By measuring the detonation velocities of the mixtures, the parameters of the explosive were calculated, characterizing their effect on the environment. Different designs of charges were formed in the drilled charging cavities of the models. It has been established that a heel with a hardening mixture increases its residence time in the borehole by 20% in comparison with other designs of charges, creating a reliable locking of detonation products. This increases the degree of explosive energy use for the destruction of the rock mass, the uniformity of its crushing, and also reduces the volume of fine dust emission into the atmosphere. Scientific novelty. A technique has been developed for determining the optimal compositions, properties of the hardening mixture and the technology for its preparation. It is shown that damming with a hardening mixture reduces the volume of fine dust emission into the atmosphere. Practical value. An acute problem for mining enterprises is the uniformity of crushing of the rock mass, the working conditions of workers during blasting operations in mine workings in hard rocks, when there are significant emissions of dust into the atmosphere. These emissions create working conditions that are not allowed by sanitary standards. This work is aimed at developing measures to reduce the intake of the finest dust into the mountain atmosphere.