The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
David Laurence - One of the best experts on this subject based on the ideXlab platform.
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establishing a sustainable Mining Operation an overview
Journal of Cleaner Production, 2011Co-Authors: David LaurenceAbstract:Abstract In a review of the literature on sustainability in Mining, it was found that there is limited guidance for mine operators to put sustainability frameworks and theory into action on the ground. This paper argues that operators can improve the sustainability of their mine sites by ensuring that leading practices are implemented in five areas. In addition to the widely-accepted dimensions of Environment, Economic and Community, Safety and Resource Efficiency must be addressed. The need for highlighting these additional elements is demonstrated in an analysis of over one thousand unplanned or prematurely closed mines over the past 30 years.
Mohammad Waqar Ali Asad - One of the best experts on this subject based on the ideXlab platform.
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Production phase and ultimate pit limit design under commodity price uncertainty
European Journal of Operational Research, 2016Co-Authors: Snehamoy Chatterjee, Manas Ranjan Sethi, Mohammad Waqar Ali AsadAbstract:Open pit mine design optimization under uncertainty is one of the most critical and challenging tasks in the mine planning process. This paper describes the implementation of a minimum cut network flow algorithm for the optimal production phase and ultimate pit limit design under commodity price or market uncertainty. A new smoothing splines algorithm with sequential Gaussian simulation generates multiple commodity price scenarios, and a computationally efficient stochastic framework accommodates the joint representation and processing of the Mining block economic values that result from these commodity price scenarios. A case study at an existing iron Mining Operation demonstrates the performance of the proposed method, and a comparison with conventional deterministic approach shows a higher cumulative metal production coupled with a 48% increase in the net present value (NPV) of the Operation.
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A review of cut-off grade policy models for open pit Mining Operations
Resources Policy, 2016Co-Authors: Mohammad Waqar Ali Asad, Muhammad Asim Qureshi, Hyong Doo JangAbstract:Abstract In an open pit Mining Operation, the heterogeneity of the grade-tonnage distribution of the deposit dictates that all available material within the boundaries of an open pit may not be processed. Given this heterogeneity, it is imperative that the valuable (ore) and waste materials are clearly identified. In this context, the cut-off grade defines the quantity of ore and waste, ensuring smooth supply of ore to the processing streams. While, the earliest significant effort towards the development of models for cut-off grade policy dates back to 1960s, a number of contributions on this vital aspect of a Mining Operation have been made since then. This paper presents a comprehensive overview of the available literature on cut-off grade policy models and suggests possible areas of future research.
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a heuristic approach to stochastic cutoff grade optimization for open pit Mining complexes with multiple processing streams
Resources Policy, 2013Co-Authors: Mohammad Waqar Ali Asad, Roussos DimitrakopoulosAbstract:Abstract Cutoff grade specifies the available supply of metallic ore from an open pit mine to the multiple processing streams of an open pit Mining complex. An optimal cutoff grade strategy maximizes the net present value (NPV) of an open pit Mining Operation subject to the Mining, processing, and marketing/refining capacity constraints. Even though, the quantities of material flowing from the mine to the market are influenced by the expected variation in the available metal content or inherent uncertainty in the supply of ore, the majority of cutoff grade optimization models not only disregard this aspect and may lead to unrealistic cash flows, but also they are limited in application to an open pit Mining Operation with single processing facility. The model proposed herein determines the optimal cutoff grade policy based on a stochastic framework that accounts for uncertainty in supply of ore to the multiple ore processing streams. An application on a large-scale open pit Mining Operation develops a unique cutoff grade policy along with a portfolio of Mining, processing, and marketing/refining rates. Owing to the geological uncertainty, the approach addresses risk by showing a difference of 14% between the minimum and maximum production rates, cash flows and NPV.
Yi Luo - One of the best experts on this subject based on the ideXlab platform.
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An improved influence function method for predicting subsidence caused by longwall Mining Operations in inclined coal seams
International Journal of Coal Science & Technology, 2015Co-Authors: Yi LuoAbstract:Prediction of surface subsidence caused by longwall Mining Operation in inclined coal seams is often very challenging. The existing empirical prediction methods are inflexible for varying geological and Mining conditions. An improved influence function method has been developed to take the advantage of its fundamentally sound nature and flexibility. In developing this method, the original Knothe function has been transformed to produce a continuous and asymmetrical subsidence influence function. The empirical equations for final subsidence parameters derived from collected longwall subsidence data have been incorporated into the mathematical models to improve the prediction accuracy. A number of demonstration cases for longwall Mining Operations in coal seams with varying inclination angles, depths and panel widths have been used to verify the applicability of the new subsidence prediction model.
Drew Dawson - One of the best experts on this subject based on the ideXlab platform.
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sleep in a live in Mining Operation the influence of start times and restricted non work activities
Applied Ergonomics, 2010Co-Authors: Sally A Ferguson, Angela Baker, Nicole Lamond, David J Kennaway, Drew DawsonAbstract:The amount of sleep obtained between shifts is influenced by numerous factors including the length of work and rest periods, the timing of the rest period relative to the endogenous circadian cycle and personal choices about the use of non-work time. The current study utilised a real-world live-in Mining environment to examine the amount of sleep obtained when access to normal domestic, family and social activities was restricted. Participants were 29 Mining operators (26 male, average age 37.4 ± 6.8 years) who recorded sleep, work and fatigue information and wore an activity monitor for a cycle of seven day shifts and seven night shifts (both 12 h) followed by either seven or fourteen days off. During the two weeks of work participants lived on-site. Total sleep time was significantly less (p < 0.01) while on-site on both day (6.1 ± 1.0 h) and night shifts (5.7 ± 1.5 h) than days off (7.4 ± 1.4 h). Further, night shift sleep was significantly shorter than day-shift sleep (p < 0.01). Assessment of subjective fatigue ratings showed that the sleep associated with both days off and night shifts had a greater recovery value than sleep associated with day shifts (p < 0.01). While on-site, participants obtained only 6 h of sleep indicating that the absence of competing domestic, family and social activities did not convert to more sleep. Factors including shift start times and circadian influences appear to have been more important.
J Benndorf - One of the best experts on this subject based on the ideXlab platform.
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application of efficient methods of conditional simulation for optimising coal blending strategies in large continuous open pit Mining Operations
International Journal of Coal Geology, 2013Co-Authors: J BenndorfAbstract:Abstract The delivery of in-spec coal qualities is essential for an efficient and environmental friendly Operation of modern coal-fired power plants. The design of the Mining Operation systems and blending opportunities plays a key role in homogenising variability and improving the prediction of key quality parameters, such as the calorific value (CV). Modern methods of conditional simulation in geostatistics allow for generating several realisations for large deposits capturing in-situ variability of key quality parameters. Integrating simulated realisations of the deposit with a simulation of transport- and blending models of Mining Operation leads to valuable insights into its performance as a function of the technical design and Operational mode. The contribution first reviews the method of Generalised Sequential Gaussian Simulation (GSGS), which is especially designed for computational efficient simulation of large deposits. In a second step GSGS is applied to a large coal field in Eastern Europe. The practical simulation process is described and applied in a complex geological environment of highly variable seam geometry and quality including multiple split seams. Results are applied to a large open pit coal Operation to investigate the variability of the calorific value and its behaviour along the extraction, transportation and blending process in a continuous Mining environment. The described approach provides a valuable view into the performance of a continuous Mining system in terms of homogenisation. Conclusions can be drawn to optimise the design of key equipment and to adjust the Operation mode to ensure that the customer's requirements in terms of coal quality variability are met with high probability.