Mining Institute, Kola Science Center, Russian Academy of Sciences, Apatity, Russia:

S. A. Kozyrev, Head of Laboratory, Doctor of Engineering Sciences

Mineral Mining and Processing Management, Kola GMK, Zapolyarny, Russia:

N. V. Safonov, Head of Mining Department, SafonovNV@kolagmk.ru
V. A. Matveenko, Head of Geological Information System and Mining Planning Department

Severny Mine is a main mineral mining division of Kola Mining and Metallurgical Company (Kola GMK), located in the Pechenga district of the Murmansk Region. This division includes Severny, Severny-Gluboky and Kaula-Kotselvaara mines. Mining operations use different extraction systems. Development of Zhdanovskoe and Zapolyarnoe deposits is carried out using three systems of mining: caving with single-end ore drawing, sublevel caving with room-and-pillar, and room-and-pillar. At Kotselvaara-Kammikivi and Semiletka deposits, blasting in sublevel drifts and sublevel caving are in use. The largest output (up to 90 %) is produced by the systems of sublevel caving with single-end ore drawing using powerful self-propelling machinery. The main factors which influence ore fragmentation quality at Severeny-Gluboky Mine, Kola GMK are described. The blasting-induced damage in the form of cracks, indents and cascading in boreholes is revealed. The detonation and energy parameters of an emulsion explosive being used are determined on a full scale and on a testing site. On this basis, the actual explosive properties of different explosives are calculated, and the rational blasting parameters are found for boreholes with a diameter of 89 and 102 mm. For the rhomb-shaped extraction panels adopted in the mine, the patterns of drilling, charging and blasting are proposed with regard to the specified rates of drilling-and-blasting. It is shown that for the integrity of boreholes and their reduced deviation from the design variants, the vertical drilling pattern is preferable. This pattern ensures high drawing performance and better rock fragmentation quality.

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