A comprehensive gold oxide heap leach model: Development and validation

McBride, D.; Gebhardt, J.E.; Cross, M.

doi:10.1016/j.hydromet.2011.12.003

Cited by 27 publications

(14 citation statements)

References 31 publications

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“…It can be obtained by fitting the permeability values of a series of models that have porosities close to the percolation threshold. The derivative models generated by the deflation process are used for computation of permeability and then fitted with a linear relationship in the log-log plot to obtain μ. Permeability is simulated by a Navier-Stokes solver (Rief et al, 2007;Wiegmann, 2007), which uses the finite volume method (McBride et al, 2012;Mostaghimi & Mahani, 2010;Mostaghimi et al, 2014;Mostaghimi, Percival, et al, 2015).…”

Section: Scaling Law Of Permeabilitymentioning

confidence: 99%

Topological Characterization of Fractured Coal

et al. 2017

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Coal transport properties are highly dependent on the underlying fractured network, known as cleats, which are characterized by geometrical and topological properties. X‐ray microcomputed tomography (micro‐CT) has been widely applied to obtain 3‐D digital representations of the cleat network. However, segmentation of 3‐D data is often problematic due to image noise, which will result in inaccurate estimation of coal properties (e.g., porosity and specific surface area). To circumvent this issue, a discrete fracture network (DFN) model is proposed. We develop a characterization framework to determine if the developed DFN models can preserve the topological properties of the coal cleat network found in micro‐CT data. We compute the Euler characteristic, fractal dimension, and percolation quantities to analyze the topology locally and globally and compare the results between micro‐CT data (before denoising), filtered micro‐CT data (after denoising), and the DFN model. We find that micro‐CT data with noise have extensive connectivity while filtered micro‐CT data and DFN models have similar topology both globally and locally. It is concluded that the topology of the DFN models are closer to that of the realistic cleat network that do not have segmentation‐induced pores. In addition, micro‐CT imaging always struggles with the trade‐off between sample size and resolution, while the presented DFN models are not restricted by imaging resolution and thus can be constructed with extended domain size. Overall, the presented DFN model is a reliable alternative with realistic cleat topology, extended domain size and favorable data format for direct numerical simulations.

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Section: Scaling Law Of Permeabilitymentioning

confidence: 99%

Topological Characterization of Fractured Coal

et al. 2017

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“…The general heap leach model is implemented within a computational fluid dynamics (CFD) multi-physics software framework. A detailed description of the mathematical models and algorithms is given by (Bennett et al, 2012b) for copper sulfide ores and for oxide ore (McBride et al, 2012b). The host code, PHYSICA, provides a three-dimensional finite volume unstructured mesh modular framework for multi-physics modeling (Croft et al, 1995).…”

Section: Heap Leach Modelmentioning

confidence: 99%

Optimization of a CFD – Heap leach model and sensitivity analysis of process operation

McBride

Croft

Cross

et al. 2014

Minerals Engineering

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A comprehensive heap leach model, developed within a computational fluid dynamics software framework, provides a modeling tool to capture reactive dissolution in low grade ores of oxide and sulfide minerals. These systems involve suites of very complex reactions, which are closely coupled with thermal conditions and key microbial populations. One of the key challenges when modeling heap leach scenarios is characterization of the ores and parameterization of the model in order to utilize the model as an investigative tool. The calibration of the model can be a lengthy process requiring many simulation runs. An optimization tool has been incorporated into the model to allow automated searching for multiple 'best fit' parameter values and to determine sensitivity. Once the model has been parameterized, large-scale forecasts can be simulated or a sensitivity analysis can be performed to investigate a range of process variables, such as irrigation rate, lift, air injection, acidity, head grade and dripper emitter spacing, amongst others. One such example is explored here for the Zaldivar ore body.

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“…Mostaghimi et al [23,24] applied CFD technology to capturing flow in a three-dimensional heap. McBride et al [25][26][27] coupled flow-solid-gas and chemical interactions within a CFD model and applied the model to a three-dimensional heterogeneous heap with variable permeability, saturated conditions and solution traveling through preferential pathways. Local variation in permeability and torturous liquid flow paths through the micro-macro pore network has been captured by utilizing a dual pore-system [28] and by incorporating local voidage heterogeneities into the particle size distribution of the ore [29].…”

Section: Introductionmentioning

confidence: 99%

“…The particle scale micro-model is often coupled to a fluid macro-model. The shrinking core model is normally coupled to the macro model by an explicit formulation as the implicit formulation is computationally expensive [17,19,25]. More recently Ferrier et al [33] replaced the diffusion-reaction equation with a product of explicit functions, which significantly reduced computational time whilst retaining accuracy.…”

Section: Introductionmentioning

confidence: 99%

Heap Leaching: Modelling and Forecasting Using CFD Technology

McBride

Gebhardt²,

Croft

et al. 2018

Minerals

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Heap leach operations typically employ some form of modelling and forecasting tools to predict cash flow margins and project viability. However, these vary from simple spreadsheets to phenomenological models, with more complex models not commonly employed as they require the greatest amount of time and effort. Yet, accurate production modelling and forecasting are essential for managing production and potentially critical for successful operation of a complex heap, time and effort spent in setting up modelling tools initially may increase profitability in the long term. A brief overview of various modelling approaches is presented, but this paper focuses on the capabilities of a computational fluid dynamics (CFD) model. Advances in computational capability allow for complex CFD models, coupled with leach kinetic models, to be applied to complex ore bodies. In this paper a comprehensive hydrodynamic CFD model is described and applied to chalcopyrite dissolution under heap operating conditions. The model is parameterized against experimental data and validated against a range of experimental leach tests under different thermal conditions. A three-dimensional 'virtual' heap, under fluctuating meteorological conditions, is simulated. Continuous and intermittent irrigation is investigated, showing copper recovery per unit volume of applied leach solution to be slightly increased for pulse irrigation.

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A comprehensive gold oxide heap leach model: Development and validation

Cited by 27 publications

References 31 publications

Topological Characterization of Fractured Coal

Topological Characterization of Fractured Coal

Optimization of a CFD – Heap leach model and sensitivity analysis of process operation

Heap Leaching: Modelling and Forecasting Using CFD Technology

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