Increasing regulatory and social demands are key driving forces behind operational changes taking place in mining. As tailings storage facilities (TSFs) come under scrutiny, operators are looking at alternative tailings management strategies. Integrated tailings management, including technical, economic, environmental, social, and risk aspects of the operation is urgently required. Current evaluation methodologies used to decide on the preferred method are limited, and have often poorly addressed the issue of realistic financial provisioning for the responsible disposal of tailings. The use of high-density tailings may be the best available option in many cases. However, it is often deemed undesirable because of economics – a conclusion that sometimes results from short-term profit-based assessments. Furthermore, there is a recognised lack of information on the costs of dewatering technologies to aid in tailings management decision-making.
This paper reports on an economic evaluation completed for comparing the lifecycle costs of disposing a typical non-acid generating gold tailings in the Goldfields of Western Australia. Conceptual TSF designs were developed and costed for managing the tailings as slurry, thickened, and filtered. Key elements driving the costs of disposal are highlighted and discussed. The concepts of the West Australian Mining Rehabilitation Fund (MRF) are introduced and considered in the estimates. In the context of increasing tailings management challenges, changes in the lifecycle costs over a range of possible future case scenarios are presented within the results to evaluate to what extent different TSF designs and closure strategies have on driving the costs of disposal in the long-term. The paper ends with a discussion addressing the long-standing challenges of financially quantifying the ‘real’ costs of surface tailings disposal. An appropriate comparison depends on the assessment of the accumulated costs resulting from a more holistic approach. This serves to enable decision makers to decide on the best practice for tailings disposal efficiency to ensure sound environmental and social performance.
Keywords: tailings management, cost comparison, tailings storage facility design, Mining Rehabilitation Fund
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