From the organization and state of drilling and blasting works largely depends on the management of stocks of blasted rock mass and rhythmicity of work of quarries. As reported data show, the cost of preparation of rocks for excavation at the quarries of the Polar region is 1.5-2 times higher than at the quarries of the central regions of the country with similar mining conditions. Improvement of technology and organization of drilling and blasting operations at the quarries of the Polar region allowed to significantly increase the provision of excavators with blasted rock mass.

The rhythmicity of work of quarries in the Polar region depends on numerous factors and, first of all, on severe climatic conditions, the influence of which leads to a decrease in the productivity of quarries and violation of the rhythm of their work. To take into account the severity of the climate, correction factors are introduced to the production rates in different periods of the year. However, seasonal fluctuations in general are insufficiently studied, although the laws of seasonality are very important to take into account when planning and organizing production processes. On the other hand, at the quarries of the Polar region it is very important to use favorable periods of the year for intensification of mining operations.

Mechanical drilling of boreholes on granite quarries of the Karelian Isthmus in view of high strength and abrasiveness of rocks - expensive and insufficiently productive method. For definition of possibility of application on granite quarries of fire drilling of boreholes by chair of open and drilling and blasting works of the Leningrad mining institute the drillability of granites of some deposits of the Leningrad area (Rovnoe, Erkil, Vozrozhdeniya and Kamennogorsky) is investigated. The studies were carried out with the use of small-scale jet burners (RGR-2, RTB-V5, MIRGEM), operating on oxygen-kerosene and benzene-air mixtures. Their technical characteristics are as follows ...

At quarries of the Leningrad region granite stripping is conducted, placing charges of explosives in vertical wells in diameter of 105 mm. Usually after explosions the bottom of a ledge turns out extremely uneven, ledges (sills) sometimes reach one third of height of a ledge. Due to the uneven bottom of the ledge productivity of excavators EKG-4 does not exceed 250 thousand m^3/ year, ie about half as much as at the advanced mining enterprises.