Li, AL, Been, K, Wislesky, I, Eldridge, T & Williams, D 2012, 'Tailings initial consolidation and evaporative drying after deposition', in R Jewell, AB Fourie & A Paterson (eds), Proceedings of the 15th International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 25-42, https://doi.org/10.36487/ACG_rep/1263_03_Li
Tailings and mine waste management has an ever-growing importance in mining, including the oil sands industry. Dewatering technologies are being adopted and further developed to reduce the environmental and social impacts of tailings management facilities as well as the risks associated with possible failure of dams that retain liquid or liquefiable tailings. The geotechnical performance of tailings deposits is one of the key issues that needs to be fully addressed for large mining projects, including oil sands projects. It has been demonstrated (Li et al., 2009) that the initial void ratio of tailings immediately following deposition is a critical parameter that affects the performance of tailings deposits under both static and seismic loading conditions, particularly the post-liquefaction stability of tailings deposits.
This paper presents a design method that draws upon geotechnical modelling techniques to predict the initial void ratio of tailings following self-weight consolidation and evaporative drying achieved through thin layer deposition. The self-weight consolidation model is based on a large strain consolidation theory (Gibson et al., 1967). For evaporative drying, the governing equation is based on a desiccation model (Gilliland and Sherwood, 1933) established for moisture migration within fine-grained soils due to evaporative drying, but the method also incorporates the soil-water characteristic curve equation (Fredlund and Xing, 1994). Analytical solutions have been derived for the governing equations. The modelling tools developed and presented in this paper provide a means to estimate an optimum layer thickness and drying period to increase in situ density of tailings and reduce the liquefaction potential of tailings deposits.
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