Copeland, A, Daigle, V & Strauss, A 2023, 'Is the implementation of dry stacking for tailings storage increasing? A Southern African perspective', in GW Wilson, NA Beier, DC Sego, AB Fourie & D Reid (eds), Paste 2023: Proceedings of the 25th International Conference on Paste, Thickened and Filtered Tailings
, University of Alberta, Edmonton, and Australian Centre for Geomechanics, Perth, pp. 611-619, https://doi.org/10.36487/ACG_repo/2355_46
It is good practice in the early phases of a new mine design, or when a new tailings storage facility (TSF) is required at an existing mine, to consider alternatives and carry out trade-off studies for tailings storage. These studies should include multiple sites and at least two disposal methods or technologies with the aim of identifying the best tailings management system for the project, generally the most cost-effective, socially and environmentally acceptable system. Dry stacking is gaining credibility and is seen as a preferred technology to manage project specific risks for various reasons: lower risk of failure, increased water conservation and water cost saving, project stakeholders and environmental considerations, better geochemical mitigation, and possible improvement in metal recovery during filtration through additional mineral dissolution. In some cases, the drivers for considering dry stacking are obvious, such as a mine located in a dry climate or new regulations, but in other places this is less obvious.
This paper evaluates the outcomes of a number of such trade-off studies mostly in Southern Africa or arid regions of Africa, which include:
The paper also looks at two mines where filtered tailings has been implemented, their overall TSF operating and stability performance, as well as opportunities and challenges of the technology. No names of the mines are included, as the focus is on whether there is an increased move towards dry stacking, and what obstacles are being experienced.
Keywords: dry stacking, filtered tailings, trade-off studies, tailings dewatering, arid climate, risk mitigation, geochemistry
South African Department of Environmental Affairs 2013, National Environmental Management: Waste Act: Regulations, Notice 634 of 2013.