Sublevel retreat mining in the subarctic: a case study of the Diavik Diamond Mine

摘要

Diavik Diamond Mine is located on the subarctic tundra of the Northwest Territories, Canada, 300 km northeast of Yellowknife. When its first two open pits were exhausted in 2012, it completed the full transition to underground mining. Three orebodies are currently being mined underground using two mining methods: blasthole open stoping and sublevel retreat (SLR). SLR was not an original method as described in the feasibility study. As the pits were mined, the underground project developed, and additional information became available. Over time, it became apparent that SLR would be the optimal method for two of the orebodies. A great deal has been learnt throughout development and operation of the SLR method at Diavik. This paper examines considerations for ventilation, production drilling and blasting, geotechnical concerns, and operational constraints for SLR mining in the subarctic. It also describes the process for method selection and the overall lessons learned.