The Norilsk polymetallic deposit is developed by underground mining in difficult mining and geological conditions. The ore deposit is located in the permafrost zone, has intensively developed fracturing, a thick cover of overlying rocks and is characterized by the release of methane into underground workings from coal seams underlying the ore deposit. At the Zapolyarny mine (formerly named No. 7/9) disseminated ores were mined using a chamber-and-pillar system with ore storages or with breaking from sublevel drifts. These systems were abandoned because they did not provide safe working conditions for miners and stability of inter-chamber pillars.