Sherriff, BL, Etcheverry, DJ, Sidenko, NV & Van Gulck, J 2011, 'Spatial and temporal evolution of Cu-Zn mine tailings during dewatering', in AB Fourie, M Tibbett & A Beersing (eds), Mine Closure 2011: Proceedings of the Sixth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 383-385, https://doi.org/10.36487/ACG_rep/1152_40_Sherriff
(https://papers.acg.uwa.edu.au/p/1152_40_Sherriff/)
Abstract: The Ruttan Cu-Zn Mine produced about 50 Mt of fine-grained tailings over 30 years. Since the closure of the mine in 2002, the tailings have been systematically dewatered through trenches draining into the open pit. This study evaluated the evolution of tailings that were underwater until 2002. Acid generation is dominated by the oxidisation of the abundant pyrite and pyrrhotite comprising 25 wt.% of tailings. Metals are temporarily attenuated from waters associated with the tailings, either absorbed on Fe oxy-hydroxide precipitates or as evaporite minerals at the surface of the tailings. While some secondary phases are stable, evaporites are only temporary metal sinks as they can re-dissolve. The pH of pore water and shallow groundwater decreased first to 4.5 and then stabilised at values of 2–3. Metal contents of ground and surface water are increasing but Ruttan Lake is maintaining a constant composition.