Authors: Williams, DJ; McGhie, A; Short, T

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2215_57

Cite As:
Williams, DJ, McGhie, A & Short, T 2022, 'Repurposing of the Genex Kidston mine site in Queensland, Australia', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: 15th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 789-802, https://doi.org/10.36487/ACG_repo/2215_57

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
The Genex Kidston mine site is among the best examples in Australia of repurposing post-closure. The paper presents the rehabilitation history of the Kidston mine site as it approached closure in 2001, and the performance of the rehabilitation over the last 20 to 25 years. The rehabilitation strategy adopted by Kidston for their surface waste rock dump was to selectively place the mineralised material within a 50 to 60 m wide side encapsulation of fresh barren waste rock, and to construct an innovative store and release cover comprising oxide waste over the top of the dump revegetated with native trees, shrubs, and grasses. The dump rehabilitation aims were to prevent the exposure of the mineralised waste rock to rainfall infiltration incident on the free-draining fresh barren rock angle of repose slopes, and for the top cover to minimise the net percolation of incident rainfall into any underlying mineralised waste rock, which it has been demonstrated to achieve. For the surface tailings storage facility, the upper exposed layer of tailings oxidised and the oxidation products were largely leached by rainfall infiltration, resulting in a slightly alkaline pH, and rendering the tailings surface suited to direct revegetation with the addition of fertiliser and initial irrigation. The tailings also have a relatively low permeability. Both the low permeability of the tailings and the revegetation with native trees, shrubs and grasses serve to limit the net percolation of rainfall. Genex Power Limited purchased the Kidston mine site in 2016 with the aim of converting it to a Renewable Energy/Battery Hub, including a Solar Farm, on the surface tailings storage facility, and constructing a Pumped Storage Hydro Project, taking advantage of the two open pits. These facilities are described in the paper, which also provide the opportunity for the long-term management of the former mine site.

Keywords: post-closure repurposing, rehabilitation, slope treatment, tailings storage facility, waste rock dump

References:
AECOM 2018, Initial Advice Statement, Kidston Pumped Storage Hydro Project, revision 8, repared for Genex Power Limited.
Benson, CH, Albright, WH, Roesler, AC & Abichou, T 2002, ‘Evaluation of final cover performance: Field data from the Alternative Cover Assessment Program (ACAP)’, Proceedings of Waste Management ’02 Conference, Tucson, p. 18.
Bews, BE, O’Kane, MA, Wilson, GW, Williams, DJ & Currey, NA 1997, ‘The design ‘of a low flux cover system, including lysimeters, for acid generating waste rock in semi-arid environments’, Proceedings of 4th International Conference on Acid Rock Drainage, Vancouver, pp. 747–762.
International Network for Acid Prevention 2009, Global Acid Rock Drainage Guide, INAP, Paris,
Mulligan, DR, Gillespie, MJ, Gravina, AJ & Currey, NA 2006, ‘An assessment of the direct revegetation strategy on the tailings storage facility at Kidston gold mine, North Queensland, Australia’, in AB Fourie & M Tibbett (eds), Mine Closure 2006: Proceedings of the First International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 371–381,
Williams, DJ 2019, ‘Obstacles to effective mine closure, rehabilitation and relinquishment’, Proceedings of Tailings and Mine Waste 2019 Conference, Vancouver, pp. 1271–1286.
Williams, DJ, Currey, NA, Ritchie, P & Wilson, GA 2003, ‘Kidston waste rock dump design and “store and release” cover performance 7 years on’, Proceedings of 6th International Conference on Acid Rock Drainage, Cairns, pp. 747–762.
Williams, DJ, Stolberg, DJ & Currey, NA 2006, ‘Long-term performance of Kidston’s “store/release” cover system over potentially acid forming waste rock dumps’, Proceedings of the Seventh International Conference on Acid Rock Drainage, St Louis, Missouri, USA, 26–30 March 2006, pp. 2385–2396.




© Copyright 2022, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
Please direct any queries or error reports to repository-acg@uwa.edu.au