Three‐Dimensional Modeling of Tailings Beach Shape

Abstract

Tailings (mining waste) disposal is a significant consideration for the mining industry, with the majority of the ore processed in most mining operations ending up as tailings. This creates large volumes of tailings, which must be handled and stored responsibly to avoid potential environmental catastrophes. The most common form of tailings storage facility is the impoundment, where tailings are contained within a basin, with beaches forming around the perimeter of the impoundment and a pond standing in the middle. A relatively new method of tailings storage is to create a "stack," whereby the tailings solids form a large heap, with the discharge of tailings slurry from the apex of the heap. This method of tailings storage is finding greater popularity as the industry seeks to reduce the amount of water discharged with the tailings, and usually features the discharge of non-segregating tailings slurry that flows turbulently in its own self-formed channel down the tailings beach. It is of significant interest for mine operators and tailings engineers to be able to predict the shape of the beach that forms in either of these disposal scenarios. The key to being able to do this relies on a method of prediction of the beach slope. In this article two new beach shape models are presented for the three-dimensional (3-D) geometric modeling of the beach surface of a tailings stack that has been formed through the variable discharge of a non-segregating slurry that periodically changes in its composition, whereby the overall discharge output is defined as a sequence of smaller finite periods of steady uniform discharge, each having its own resulting beach slope. A beach slope model previously presented by the authors has been used here to predict the applicable beach slope for each finite discharge regime. The shape models presented here present two different methods for the compounding of the individual tailings deposits that are generated by each of these finite discharge * To whom correspondence should be addressed. E-mail: Satinath. Bhattacharya@rmit.edu.au. regimes. Historic tailings discharge data is run through both models, and the shapes predicted by the models are compared with aerial survey data of real tailings stacks. This work not only presents a method of tailings stack shape prediction, but also a plausible theory for explaining the concavity of tailings beaches. The models also have the potential to be developed further for the 3-D modeling of tailings beaches formed in other types of storage facilities, such as impoundments or valleys.

Generic modelling of desiccation for cyclic deposition of thickened tailings to maximise density and to minimise oxidation

“…The absence of a water cover increases the risk of acid generation in sulphidic tailings, while rain-driven erosion may also be a concern in very humid climates. Directing tailings during deposition to control layer thickness and the overall the geometry of the stack can be difficult due to variability in the rheology the tailings coming out of the pipe, as well as lack of understanding of the overland flow, though this is improving through increased operational experience and research (Shuttlewoth et al, 2005;Fitton et al, 2008;Henriquez and Simms, 2009;McPhail, 1995).…”

Beaching angles and evolution of stack geomoetry for thickened tailings - a review

“…On the issue of concavity, the authors propose two explanations as to why non-segregating tailings should produce an equilibrium beach slope profile with curvature. Fitton (2007) ascribes concavity to variability in the properties of the tailings delivered, and has developed beach slope modelling methods using this assumption (Fitton et al, 2008). By contrast, in the method of McPhail (1995) concavity is built into the equation for stream power dissipation.…”

“…For prediction of the equilibrium beach profile for stacks where channel flow dominates, some researchers have used the concept of equilibrium between erosion and sedimentary deposition (Fitton et al, 2008;Pirouz and Williams, 2007). Others have pursued an approach based upon dissipation of kinetic energy of the tailings stream as it travels down the slope of the stack (McPhail, 1995(McPhail, , 2008.…”

“…The following model has been largely developed by Tim Fitton (Fitton et al, 2006(Fitton et al, , 2007(Fitton et al, , 2008Fitton, 2007). The model integrates non-Newtonian open channel flow and sediment transport.…”

Recycling and utilisation of industrial solid waste: An explorative study on gold deposit tailings of ductile shear zone type in China

“…Though a good many studies (Changul et al, 2010;Das and Maiti, 2008;Fanfani et al, 1997;Fitton et al, 2008;Hiller et al, 2013;Madejón et al, 2010;Meunier et al, 2011;Ribeta et al, 1995;Rodríguez et al, 2009;Stoltz and Greger, 2002;Wei et al, 2009. The relatively low content of gold in gold deposits results in large amounts of discharge of tailings in the course of mining.…”