Predicting void ratio for surface paste tailings deposition

Authors: Salfate, ER; Wilson, GW; Wijewickreme, D; Simms, P Download Paper

DOI https://doi.org/10.36487/ACG_rep/1008_39_Salfate

Cite As:
Salfate, ER, Wilson, GW, Wijewickreme, D & Simms, P 2010, 'Predicting void ratio for surface paste tailings deposition', in R Jewell & AB Fourie (eds), Mine Waste 2010: Proceedings of the First International Seminar on the Reduction of Risk in the Management of Tailings and Mine Waste, Australian Centre for Geomechanics, Perth, pp. 473-485, https://doi.org/10.36487/ACG_rep/1008_39_Salfate



Abstract:
Paste tailings have proven to be a reliable technology with advantages in terms of safety and water savings. Although safety is always the priority when designing this type of facilities, effective water usage has turned out to be of special importance for dry regions where the benefits of saving water often justify the use of this technology. Current design requirements have revealed the need to reliably predict the deposited and post- deposited void ratio and density of the paste. These properties are fundamental for determining the stability of paste impoundments, especially under undrained conditions. This paper presents an overview of the modelling framework under which some of the initial properties of paste tailings can be predicted. The approach is based on the application of unsaturated soil mechanics, through which drying and volume change of the paste can be related. The results using this framework seem to correlate well with those from drying tests performed in the laboratory, thus confirming the validity of the modelling approach. Several case scenarios were evaluated using this modelling framework. Variables such as paste layer thickness, drying time of the paste, and climate have been modified to observe their effect over water content and void ratio distribution. The results presented herein demonstrate how void ratio and density of the paste would change under different operational and climatic conditions. The long-term goal of the research is to develop a model that may be used as a planning tool during the design stages of paste tailings storage facilities.

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