Authors: Errázuriz, T
Show More
Open access courtesy of:

Citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
The application of highly thickened tailings technologies is rapidly increasing due to the perceived benefits with respect to reduction of environmental impacts, water saving and potential reductions in dam size and impoundment footprint. Evaluation of these potential benefits requires that during design stages an understanding is developed of the range of feasible beach slopes to be achieved during deposition. A comprehensive evaluation of the operational factors influencing the beach formation process is paramount to ensure that expected performance during design stages is met throughout operations. This paper presents the derivation of a dimensionless parameter for non-Newtonian flows, associated with sheet flows on an inclined plane, which directly relates to the tailings beach slope expected to be formed due to subaerial disposal. This dimensionless parameter provides a closed expression for estimating tailings beach slopes based on rheological properties and discharge rates considering that sheet flow mechanisms occur. Conditions for sheet flow occurrence, such as level of further dewatering of the beach after deposition, active discharge times and geometry of active discharge areas, can be derived within this formulation. The dimensionless parameter and conditions found to promote sheet flow also allow to address the advantages and limitations of different discharge operation strategies, such as operating the tailings facility by sectors (allowing drying cycles) of varying geometries. Evaluation of this approach in the light of case histories is presented. Finally, discussion on how to evaluate the potential of having concave tailings beach profiles within this formulation is provided. Keywords: tailings beach slope estimation, tailings surface disposal, thickened tailings deposits design

Keywords:

Citation:
Errázuriz, T 2018, 'Tailings beach slopes as a dimensionless parameter of non-Newtonian flows', in RJ Jewell & AB Fourie (eds), Proceedings of the 21st International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 515-530.

References:
Been, K & Jefferies, MG 1985, ‘A state parameter for sands’, Géotechnique, vol. 35, no. 2, pp. 99–112.
Blight, GE & Bentel, GM 1983, ‘The behaviour of mine tailings during hydraulic deposition’, Journal of the South African Institute of Mining and Metallurgy, April 1983, pp. 73–86.
Fitton, TG 2007, Tailings Beach Slope Prediction, PhD thesis, RMIT University, Melbourne, (since published as a book by VDM Verlag, Saarbrucken in 2010).
Fourie, AB & Gawu, SKY 2010, ‘The validity of laboratory flume data for predicting beach slopes of thickened tailings deposits’, in RJ Jewell and AB Fourie (eds), Proceedings of the 13th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 241–253.
Ihle, CF & Tamburrino, A 2009, ‘Proposed scaling laws for laminar flow of a Bingham plastic down an inclined plane’, in RJ Jewell, AB Fourie, S Barrera and J Wiertz (eds), Proceedings of the 12th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 225–232.
Jefferies, MG & Been, K 2015, Soil Liquefaction: A Critical State Approach, 2nd edn, Taylor and Francis, Abingdon, 690 p.
Jewell, RJ 2010, ‘The evolution of paste and thickened tailings’, Newsletter of the Australian Centre for Geomechanics, vol. 35,
pp. 1–3.
McPhail, GI 1995, Prediction of the Beaching Characteristics of Hydraulically Placed Tailings, PhD dissertation, University of the Witwatersrand, Johannesburg.
McPhail, GI 2008, ‘Prediction of the beach profile of high-density thickened tailings from rheological and small-scale trial deposition data’, in AB Fourie, RJ Jewell, P Slater, A Paterson (eds), Proceedings of the 11th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 179–188.
McPhail, GI, Bello, F & Engels, J 2017, ‘Beach profile modeling at Centinela Mine, Chile’, Proceedings of the 4th International Seminar on Tailings Management, Gecamin, Santiago.
Naik, B 1883, ‘Mechanics of mudflow and treated as the flow of a Bingham fluid’, PhD thesis, Washington State University, Pullman.
Pirouz, B & Williams, MPA 2007, ‘Prediction of non-segregating thickened tailings beach slopes – a new method’, in AB Fourie and RJ Jewell (eds), Proceedings of the Tenth International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 315–327.
Simms, P, Williams, MPA, Fitton, TG & McPhail, GI 2011, ‘Beaching angles and evolution of stack geometry for thickened tailings – a review’, in RJ Jewell & AB Fourie (eds), Proceedings of the 14th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 323–338.




© Copyright 2018, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
Please direct any queries to or error reports to repository-acg@uwa.edu.au