Operations Research Applications In Underground Mine Production Scheduling

Author : Matheus Furtado E. Faria
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (131 download)

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Download or read book Stochastic Optimization of Stope Design and Long-term Underground Mining Production Scheduling for Sublevel Open Stoping Mining Operations written by Matheus Furtado E. Faria and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Underground mine planning defines the design of technically producible economic material volumes and development openings, the sequence of multiple underground activities, and the material destinations within a mineral deposit throughout the mine's life, aiming to maximize the net present value (NPV). Due to the existence of different mining methods and the inherent operational and computational complexities, this planning is commonly performed through a stepwise optimization process in which the stope layout is preliminarily designed. Subsequently, the network of developments interconnecting the production areas is conceived, defining the precedence of underground mining activities. Finally, the strategic underground mine production scheduling is optimized, the only step that accounts for the time value of money. Available optimization methods have been focused separately on each of the planning steps, which do not benefit from the synergies between the planning steps. Additionally, most of the previously mentioned methods are deterministic; that is, they neglect many sources of uncertainty, which has been extensively demonstrated to have a significant impact on the profitability and feasibility of mining operations. Therefore, this thesis proposes stochastic optimization methods for underground mines by employing a sublevel open stoping mining method and ultimately attempts to integrate the mine design and production scheduling into a single optimization framework. The first part of this thesis presents a stochastic optimization method of stope design along with the commonly used sequential underground mine planning framework. A set of geostatistical simulations is used to quantify the variability and uncertainty of grades within the mineral deposit. The proposed method aims to maximize the undiscounted profit while capitalizing on the upside potential in terms of recoverable metal of the generated stope layout. It also accounts for the development costs of potential production levels and stopes. The application of this stochastic approach at an underground gold mine achieved a 40% higher undiscounted profit and 21% recoverable metal when benchmarked against an industry-standard deterministic stope design software tool. The second part of this thesis presents an integrated stochastic optimization of stope design and long-term underground mine production scheduling by integrating time-dependent development costs and production targets. The mathematical model seeks to maximize the NPV from the scheduled stopes, as well as to minimize the shaft, drifts and crosscuts development costs and maintenance costs to keep the levels in operation while managing the risk of failing to meet yearly productions targets. Therefore, an optimal underground mine design is yielded as an output from the optimized production schedule. The method also opens new avenues to account for time-dependent sources of uncertainty that cannot be incorporated into the stope design optimization in the sequential underground mine planning framework. A case study at an underground gold mine demonstrates that the proposed method generates more selective stopes and physically different production levels, which correspond to an 11% higher NPV and a shorter life-of-mine by two years, as compared to the sequential optimization framework"--