Masengo, E, Ingabire, EP, Huza, J & Julien, MR 2024, 'Impact of the construction of a filtered tailings stack on top of an existing slurry tailings storage facility at LaRonde gold mine', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 321-334, https://doi.org/10.36487/ACG_repo/2455_26
(https://papers.acg.uwa.edu.au/p/2455_26_Masengo/)
Abstract: LaRonde is a gold mine owned and operated by Agnico Eagle Mines since 1988. LaRonde has been depositing slurry tailings in two facilities: the main tailings storage facility (TSF) and Extension A4 TSF. These two facilities reached their full storage capacity at the end of 2022. To accommodate about 12 million tonnes of additional tailings and avoid building a new conventional slurry TSF, LaRonde decided to change their tailings management strategy from slurry tailings to filtered tailings in 2019. The construction of the filtration plant started in April 2020 and was commissioned in October 2022. The selected option for the filtered tailings deposition was to build a filtered tailings stack over the existing Extension A4 TSF. The construction of the filtered tailings stack required the construction of a 1.5 to 2 m-thick waste rock platform (bridgelift) over the slurry tailings within the existing TSF. This paper presents the geotechnical investigation and characterisation of the slurry tailings and the filtered tailings stack, the instrumentation program implemented to monitor the behaviour of the slurry tailings during the construction of the bridgelift and the filtered tailings stack, plus the results of the monitoring program that have been used to verify and update the design assumptions.

Keywords: filtered tailings, slurry tailings, critical state line, monitoring, inclinometers, porewater pressures