Filizzola, B, Zhang, P & Mozaffari, S 2024, 'Mining front seismicity at Kiirunavaara mine categorization and probable triggers', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 915-924.
(https://papers.acg.uwa.edu.au/p/2435_G-04/)
Abstract: Kiirunavaara sublevel caving mine (north Sweden, owned by LKAB) is regarded as seismically active since 2007-2008 and presently has the largest seismic monitoring system in the world. Several authors have studied the characteristics of seismicity at Kiirunavaara, but still a closer look into the factors influencing mining-front related seismicity has yet not been performed. This paper aims to investigate the mining-front seismicity in Kiirunavaara mine from a production point of view (mucking data, mining-front geometry, and mining sequence) and to point out probable triggers to these events. 63 large seismic events with local magnitude ML ≥ 1.5 from 2011 to 2021 classified by previous studies as mining-front related were analysed. Based on the combined analysis of the events in mXrap, GironPlot and mucking data/graphs, the results allowed to reclassify the number of mining-front related events, and their probable influential contexts. In this paper, only the two most relevant categories: Stage I category (17 events) and Longitudinal Mining category (19 events) are presented. The Stage I category presents a scenario of stress concentration in the rock pillar between sublevels on the initial stage of production of a level, when no connection to the cave above has been established yet. The high number of events related to Longitudinal Mining reinforces the suggestion of not using this geometry in the mine. This study has brought forward relevant discussion for the future of mining in highly stressed environments, and initial suggestions on how to mitigate the mining-front related seismicity at Kiirunavaara mine.