Author 1:
Name & Surname: Tokarev O. V.
Company: Kola Mining and Metallurgical Company (Monchegorsk-7, Russia)
Work Position: Deputy Director for Minerals and Raw Materials, Head of Mine Management
Contacts: e-mail: tokarevov@kolagmk.ru

Author 2:
Name & Surname: Kuzenkov M. V.
Company: Kola Mining and Metallurgical Company (Monchegorsk-7, Russia)
Work Position: Head of Mining Department, Mine Management

Author 3:
Name & Surname: Udalov A. E.
Company: VNIMI (Saint-Petersburg, Russia)
Work Position: Head of Metalliferous and Nonmetalliferous Deposit Geomechanics Laboratory
Scientific Degree: Candidate of Engineering Sciences

The Zhdanov copper-nickel ore deposit is composed of 7 ore bodies of sublatitudinal elongation and echelon occurrence. The ore reserves at the top of the deposit have been mined out with three open pit mines down to a limit depth of 420 m (Tsentralny OPM). The open pit mining in the overall output of Kola MMC made 80%. As the open pits were approaching their ultimate limits, it was decided in 2000 to extract the remaining reserves with an underground method. The prime selection criteria for a mining method were: high productivity owing to employment of self-propelled equipment and integrated mechanization of mining; minimized amount of development work; efficient extraction of ore reserves at the minimum loss and dilution. These criteria are to the best covered by a two-stage mining approach: sublevel caving with room-and-pillar mining. At the first stage (when open pit and underground mining methods are used concurrently), the room-and-pillar system is used. At the second stage (upon open pit mining completion), rib pillars and crown pillars are broken with the sublevel caving technology and frontal ore drawing.

1. Mukhtarov T. M. Kombinirovannyy sposob razrabotki mestorozhdeniy poleznykh iskopaemykh (Combined method of mineral deposits' mining). Moscow : Nedra, 1988. 321 p.
2. Shelkanov V. A. Kombinirovannaya razrabotka rudnykh mestorozhdeniy (Combined mining of ore deposits). Moscow : Nedra, 1974. 250 p.
3. Demidov Yu. V. Kontseptsiya i nauchnye problemy kombinirovannoy razrabotki moshchnykh rudnykh mestorozhdeniy Kolskogo poluostrova (Concept and scientific issues of combined mining of large-capacity ore deposits of Kola Peninsula). Otkryto-podzemnaya razrabotka moshchnykh rudnykh mestorozhdeniy (Open-cast and underground mining of large-capacity ore deposits). Apatity : Kola Science Center of Russian Academy of Sciences, 1995. pp. 12–15.
4. Kaplunov D. R., Kalmykov V. N., Rylnikova M. V. Kombinirovannaya geotekhnologiya (Combined geotechnology). Moscow : «Ore and Metals» Publishing House, 2003. 560 p.
5. Baryshnikov V. D., Gakhova L. N., Kramskov N. P. Geomekhanicheskaya otsenka usloviy otrabotki zakonturnykh zapasov pri sformirovannykh bortakh karera (Geomechanical assessment of overboard reserve mining conditions with formed pit edges). Gornyy Informatsionno-Analiticheskiy Byulleten = Mining Informational-Analyticlal Byulletin. 2010. No. 6. pp. 223–230.
6. Lazchenko K. N., Terentev B. D. Geotekhnologicheskie sposoby razrabotki mestorozhdeniy poleznykh iskopaemykh (Geotechnological methods of mineral deposit mining). Moscow : Gornaya Kniga, 2007. 75 p.
7. Mikhaylov Yu. V. Podzemnaya razrabotka mestorozhdeniy poleznykh iskopaemykh: podzemnaya razrabotka rudnykh mestorozhdeniy v slozhnykh gorno-geologicheskikh usloviyakh : uchebnoe posobie (Underground mining of mineral deposits: underground mining of ore deposits in complex mininggeological conditions : tutorial). Moscow : Akademiya, 2008. 320 p.