Covacevich, J, Wates, J & Dal Pozzo, S 2013, 'Comparison of predictions of beach slopes using alternative models', in R Jewell,  AB Fourie, J Caldwell & J Pimenta (eds), Paste 2013: Proceedings of the 16th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 481-491, https://doi.org/10.36487/ACG_rep/1363_37_Covacevich
(https://papers.acg.uwa.edu.au/p/1363_37_Covacevich/)
Abstract: Beach slope prediction for thickened tailings is one of the key aspects to be determined by specialists before the development of the engineering phases for large scale copper sulphide ore exploitation in northern Chile. Although the main reasons for implementing thickened tailings technology in Chile are the lack of water and the high cost of bringing it from the sea, beach slope has a significant impact on the volume and cost of tailings embankments in steep terrain such as that in the Andes.

Some prediction methods assume that the beach slope equates to the slope where erosion and sedimentation reaches equilibrium. Conversely, McPhail relates the beach slope profile to ‘stream power’ whilst others have established models based on limit equilibrium conditions and energy conservation. Since there are no projects of over 100 ktpd in steady operation anywhere in the world at this time, these methods have not yet been proven suitable for predicting slopes for large-scale operations.

This paper compares beach slope predictions using the most common methods with results obtained from extensive pilot Plant trials involving deposition cells and flumes for a mining company in northern Chile. The paper discusses differences between the findings of each method and concludes with a commentary on the factors that may ultimately influence the actual beach slopes that will be obtained in practice. Finally, we provide recommendations for the design of tailings facilities given the absence of a proven prediction method.