Monastyryov M. Justification of parameters of preparation for blasting operations of construction raw materials at granite opencasts in order to improve the effectiveness of drilling and blasting operations

The aim of the work is to improve the effectiveness of broad range of drilling and blasting operations. This is achieved by choosing of efficient technological parameters of mining-hole breakage method of raw rock material. It was shown both theoretically and experimentally that creation of convergent detonation waves in mining-hole charge of blasting material (BM) using linear initiators changes the energy redistribution of blast. That energy is spent at crushing and regrinding of raw rock material and also provides decreasing of yield of oversize fractions of crushing by a factor of 3.0 with increasing of regrinding fractions by a factor of 1.3. It was proved that the type and properties of the BM and also the necessary density of the BM in mining hole have to be such that the initial pressure of explosive products in mining hole should correspond to the dynamic boundary of compressive hardness of raw rock material. The main results of the work have been implemented at mining opencasts of Donbass.