Mine Tailings Storage: Safety Is No Accident

China makes advances in tailings dam safety

In the last decade, the Chinese mining industry has made significant changes in the treatment of mine waste, including improving engineering design, construction and monitoring of tailings storage facilities. The government has increased regulation and mines are now required to have a tailings disposal system in operation before mining can begin. Improving tailings dam safety in China is vital since there are more than 12 000 tailings dams, of which more than 6 000 were in use at the last report (Chen et al. 2016). While most of these tailings dams are small, 95 per cent of them are constructed using the upstream method, which, while economical, has proven to be less stable than other methods (Wei et al. 2013). Due to the large number of failures, mine owners are now required to provide stability analyses and flood-control analyses, which are generally undertaken by professional design companies (Wei et al. 2013). Li et al. (2017) recently suggested four initiatives to improve tailings dam safety in China: • Improve supervision over the whole life cycle of tailings storage, including closure and reclamation. • Consider safety, economy and societal and environmental risks in risk analysis during the design phase. • Raise dam stability standards and maximum flood safety standards to be in line with international best practice. • A reclamation and environmental protection fund should be established by the mining enterprise at the planning and design phase. The challenge of safely storing mine waste is growing in scale and complexity. Over the last few decades, the tailings- to-ore ratio has been increasing, as mineral deposits with increasingly lower ore grades are mined (Mudd 2007). The fate of this increasing volume of waste is a major focus of the debate on the general sustainability of mining and the practicalities of storing ever-increasing quantities of tailings. This is a challenge that could be further complicated by the increased severity and occurrence of extreme weather events expected under climate change predictions (Franks et al. 2011). With community confidence shaken by recent failures, the mining industry is being challenged to guarantee the health and safety of people and the environment. The alarm over tailings dam failures, along with concerns over land access, water use and contamination, indigenous rights and inequality raises questions about the way mining contributes to sustainable development.

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