Experiences of seismic monitoring at the Kittilä mine

Authors: Pyy, A; Meyer, S; Falmagne, V Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2465_17

Cite As:
Pyy, A, Meyer, S & Falmagne, V 2024, 'Experiences of seismic monitoring at the Kittilä mine', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 341-354, https://doi.org/10.36487/ACG_repo/2465_17



Abstract:
The Kittilä gold mine in Northern Finland is owned and operated by Agnico Eagle Finland. The mining operation started in 2008 with open pits which were closed in 2012, when production moved underground. The new 1,040 m-deep hoisting shaft commenced operation in 2023. The mine consists of four separate orebodies, currently producing 2.0 Mt per annum, and requiring over 13 km of development on an annual basis. The principal mining method is longhole stoping with delayed backfill. A microseismic monitoring system was installed during early development of the Rimpi orebody. Early development and mining of the Rimpi orebody between 700 to 900 m depth from surface indicated a potential for generating a dynamic rock mass response. The evolution of the rock mass response during the development and extraction of two upper (700 to 900 level) and one lower (1,025 to 900 level) pyramid(s) is presented, including the yielding sill pillar below 900 level and stress redistribution around the stoping areas. An analysis of footwall structure activation and seismic response is presented with two examples. In both cases, stress change induced by stope extraction caused seismic events in the footwall at 50–200 m distance from the stoping. Good location accuracy of seismic events (MW > −2.3) together with routine source mechanism calculation has enabled analysis of the seismically active structures in the footwall and improved ground support planning. Microseismic monitoring is an integral part of the Kittilä mine operational safety and seismic risk management.

Keywords: microseismic monitoring, rock mass response, sill pillar

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