Assessing Post-Closure Metal Dispersion from Sulphidic Mines in the Tropical Climate of North Australia — A Case Study

Authors: Edraki, M; Noller, BN Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_repo/852_61

Cite As:
Edraki, M & Noller, BN 2008, 'Assessing Post-Closure Metal Dispersion from Sulphidic Mines in the Tropical Climate of North Australia — A Case Study', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 663-671, https://doi.org/10.36487/ACG_repo/852_61



Abstract:
This paper presents an evaluation of the historic and post-closure water chemistry data for a closed mine in northern Australia, with a wet-dry climatic cycle. Lessons learned from such studies can be useful for future mine closure planning in similar climatic conditions. There is a distinctive grouping of the samples based on major and trace element chemistry. Background locations in the nearby creek with higher calcium and magnesium concentrations present one end member, while tailings run-off with high sulphate beryllium, copper, manganese, nickel, lead, zinc, arsenic and cobalt concentrations presents another. Waste rock dump seepages have low sulphate and heavy metals. Surface drainage from the pit area has low electrical conductivity, sulphate and heavy metals. Rare earth elements proved to be potentially useful for mine water fingerprinting. The long-term trends of concentrations show a significant reduction of sulphate and heavy metals since mine closure, and an onset of rehabilitation, which is also shown in the reduction of calculated metal loads. Solute loads, compared to the 2005-2006 wet season, as a benchmark, are suggested as a better indicator for monitoring the success of rehabilitation.

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