McNaughton, CS, Crilley, LR, Damour, F, Radevski, J, Klink, M & Allen, J 2024, 'South Australia tailings storage facility: dust emissions study ', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2024: Proceedings of the 17th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 165-182, https://doi.org/10.36487/ACG_repo/2415_11 (https://papers.acg.uwa.edu.au/p/2415_11_McNaughton/) Abstract: A new copper-gold-silver mine has been developed approximately 160 km north of Port Augusta on the eastern margin of the Arcoona Plateau in South Australia, part of the traditional lands of the Kokatha people. The area is a rolling ‘gibber plain’[footnoteRef:3] surrounded by alluvial plains, stabilised dunes and salt playa such as Lake Torrens (Ngarndamukia). [3: Also ‘stoney downs’, desert or cobble pavement.] Tailings from the mine are delivered as a salt-rich slurry to the tailings storage facility (TSF); a valley-fill impoundment located at the headwaters of the local creek. The fine tailings spread and as they settle, water rises to the slurry surface. As the tailings dry in the arid South Australian climate, dissolved mineral salts crystalise (effloresce) at the tailings surface, forming a durable crust that inhibits wind erosion of the fine tailings. In 2023 BHP commissioned WSP to undertake a dust emissions study for the mine’s TSF. The study deployed a Portable In Situ Wind Erosion Laboratory (PI-SWERL) to measure dust emissions fluxes directly, as a function of wind shear stress, from undisturbed dry tailings surfaces. These measurement data are then converted into dust emissions fluxes (i.e. mg/m2/s) as a function of 10-m wind speeds (i.e. m/s). The study included PI-SWERL measurements for various tailings types, the surrounding gibber plain, regional alluvial deposits and a salt playa. The study also included ancillary measurements of surface properties (e.g. moisture content and particle sizes). Our paper presents the PI-SWERL technique and results of the dust emissions study, and includes a discussion about what the study results mean in terms of local air quality, dust deposition and the long-term (> 100 years) wind erodibility of the mine’s TSF. Keywords: tailings, tailings storage, mine closure, environmental impacts, dust, dust emissions, air quality, wind erosion, particle size