Integration of Groundwater Modelling with Mine Planning to Optimise Mine Closure Plans ⎯ The Marillana Creek (Yandi) Mine Story

Authors: Hall, JW; Middlemis, H; Waters, PJ; Rozlapa, KL Download Paper

DOI https://doi.org/10.36487/ACG_repo/605_5

Cite As:
Hall, JW, Middlemis, H, Waters, PJ & Rozlapa, KL 2006, 'Integration of Groundwater Modelling with Mine Planning to Optimise Mine Closure Plans ⎯ The Marillana Creek (Yandi) Mine Story', in AB Fourie & M Tibbett (eds), Mine Closure 2006: Proceedings of the First International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 131-137, https://doi.org/10.36487/ACG_repo/605_5



Abstract:
A major challenge for closure planning at mining operations below water table is evaporation from final void pit lakes, which can impact on downstream groundwater (and surface water) flows and quality. A closure approach that is increasingly being adopted is to infill the final voids with waste rock to above the pre- mining water table to prevent the development of a pit lake and subsequent evaporative losses. At BHP Billiton Iron Ore’s Marillana Creek (Yandi) mine, where the orebody is a channel iron deposit that forms the major aquifer in the region, this approach is not practical. With a stripping ratio of less than one, there is insufficient waste rock to infill all mine areas to the pre-mining water table. Through the integration of hydrogeological modelling with mine planning, a cost effective solution was developed, which involved selective infilling of all pits, largely using run-of-mine waste dumping, and some diversion of surface water flows. This solution will result in maintenance of adequate groundwater and surface water flows to support downstream water dependent ecosystems and maintain beneficial use.

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