10,634 research outputs found

    Risk-based evaluation for underground mine planning

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    As underground mine planning tools become more sophisticated, mine planners have the capacity to investigate numerous mine sequencing options to identify the best strategy for a given project, creating higher value for shareholders. The information required for mine planning decisions goes beyond the external sources of uncertainty recognised by typical evaluation techniques used in the mining industry, to include technical factors (e.g. mine development layout) and the ability of a mineral extraction project to achieve planned production levels. Due to the individual characteristics that define underground mining projects, each will exhibit its individual risk profile, and thus advanced evaluation techniques must capture this information.This paper describes a Risk‐based Evaluation Methodology that accounts for financial and technical scheduling risk in the evaluation of underground mining projects. It provides decision‐makers with more information early in the mine planning cycle by combining planning and design methodologies with evaluation techniques to identify, optimise and evaluate strategies for mining extraction sequences. Standard evaluation practices used in the mining industry (Discounted Cash Flow, Real Options and Monte Carlo Simulation) are combined with the concepts of Modern Portfolio Theory to establish an evaluation methodology that recognises financial uncertainty in the context of technical scheduling factors. This paper will show that the Risk‐based Evaluation Methodology can be used at the tactical level, as it is applied in combination with the Schedule Optimisation Tool (SOT), for the purpose of recommending a materials handling system to be implemented in a mining project. For the case study, the inclusion of more information in the decision‐making process not only provides a more accurate valuation and allows for the recognition of risk, but it also alters the ultimate decision

    Models and methods to make decisions while mining production scheduling

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    Purpose is to develop a new approach to the design of mining operations basing upon models and methods of decision making. Methods. The paper has applied a complex approach involving approaches of decision-making theory. Analysis of the pro-duction development scenarios is proposed for strategic activity planning; criteria to make decisions under the uncertainty conditions as well as decision-making trees for day-to-day management are proposed to determine balanced production level. Findings. It has been identified that mining production design is of the determined character demonstrating changes in “state of the nature” depending upon the made decisions. The idea of mining production is to reduce uncertainty gradually by means of analysis of production scenarios, and elimination of unfavourable alternatives. Operative management is implemented while constructing decision trees, and optimizing operation parameters. Representation of sets of rational equipment types as well as development scenarios, and their comparison in terms of decision-making parameters makes it possible to determine adequate capacity of a working area, and to reduce expenditures connected with the equipment purchase and maintenance. In this context, limiting factors, effecting anticipatory mining out-put, are taken into consideration. Successive comparison of the alternatives helps identify decision-making area for different scenarios of the production development. Originality. To manage mining production, approaches of decision-making theory have been proposed which involve the use of decision trees, decision-making criteria, and analysis of scenarios basing upon representation of operating procedures in the form of a network model within which the shortest route corresponds to optimum decision. Practical implications. Decision-making system has been developed making it possible to optimize operation parameters, to reduce prime cost of mining, and to select a structure of engineering connections with the specified production level. The described approaches may be applied at the stage of a stope design as well as in the process of a field development. Specific attention has been paid to a software development to implement the approaches.Мета. Розробити новий підхід до проектування гірничого виробництва, який базується на моделях та методах теорії прийняття рішень. Методика. В роботі застосовано комплексний метод, який включає підходи теорії прийняття рішень. Для стратегічного планування діяльності запропоновано досліджувати сценарії розвитку виробництва, для визначення раціонального рівня виробництва – критерії прийняття рішень в умовах невизначеності, а також дерева прийняття рішень для поточного управління. Результати. Виявлено, що процес проектування гірничого виробництва має детермінований характер, який демонструє зміну “станів природи” залежно від прийнятих рішень. Суть проектування гірничого виробництва зводиться до послідовного зменшення невизначеності шляхом дослідження сценаріїв виробництва та виключення несприятливих альтернатив. Оперативне управління здійснюється шляхом побудови дерев рішень та оптимізації параметрів експлуатації. Представлення множин раціональних типів обладнання, сценаріїв розвитку подій та порівняння їх за критеріями прийняття рішень дозволяє визначити раціональний рівень видобутку виймальної дільниці і знизити витрати на придбання та обслуговування обладнання, при цьому враховуються обмежувальні фактори, які впливають на величину очікуваного видобутку. Послідовне порівняння альтернатив дозволяє встановити поле прийнятних рішень для різних сценаріїв розвитку виробництва. Наукова новизна. Для управління гірничим виробництвом запропоновано підходи теорії прийняття рішень, які включають застосування дерев рішень, критеріїв прийняття рішень та аналіз сценаріїв, котрі базуються на представленні технологічного процесу у вигляді мережевої моделі, в якій найкоротший маршрут відповідає оптимальному рішенню. Практична значимість. Розроблена система прийняття рішень, дозволяє оптимізувати параметри експлуатації, знизити собівартість видобутку, вибрати структуру технологічних зв’язків з заданим рівнем продуктивності. Описані в роботі підходи можуть бути використані як на стадії проектування очисного забою так і в процесі експлуатації родовища корисних копалин. Особливу увагу приділено розробці програмного забезпечення для впровадження описаних підходів у виробництво.Цель. Разработать новый подход к проектированию горного производства, который базируется на моделях и методах теории принятия решений. Методика. В работе использован комплексный метод, который включает подходы теории принятия решений. Для стратегического планирования деятельности предложено исследовать сценарии развития производства, для определения рационального уровня производства – критерии принятия решений в условиях неопределенности, а также деревья принятия решений для текущего управления. Результаты. Установлено, что процесс проектирования горного производства носит детерминированный характер, который отражает изменение “состояний природы” в зависимости от принятых решений. Суть проектирования сводится к последовательному уменьшению неопределенности путем исследования сценариев производства и исключения неблагоприятных альтернатив. Оперативное управление осуществляется посредством построения деревьев решений и оптимизации параметров эксплуатации. Представление множества рациональных типов оборудования, сценариев развития событий та сравнение их по критериям принятия решений позволяет определить рациональный уровень добычи очистного участка и снизить затраты на приобретение и обслуживание оборудования, при этом учитываются ограничивающие факторы, которые влияют на величину ожидаемой прибыли. Последовательное сравнение альтернатив позволяет установить поле приемлемых решений для разных сценариев развития производства. Научная новизна. Для управления горным производством предложены подходы теории принятия решений, которые включают применения деревьев, критериев принятия решений и анализ сценариев, основанных на представлении технологического процесса в виде сетевой модели, где кратчайший маршрут соответствует оптимальному решению. Практическая значимость. Разработана система поддержки принятия решений, которая позволит оптимизировать параметры эксплуатации, снизить себестоимость добычи, выбрать структуру технологических взаимосвязей с заданным уровнем производительности. Описанные в работе подходы могут быть использованы как на стадии проектирования очистного забоя, так и в процессе эксплуатации месторождения полезных ископаемых. Особое внимание уделено разработке программного обеспечения для внедрения описанных подходов в горное дело.The study has been carried out within the framework of research project of the National Academy Sciences of Ukraine for young scientists “Resource-saving techniques to support mine workings under the complex hydrogeological conditions”; Agreement #29-04/06-2019; official registration #0119U102370

    Research methodology in montanistic tourism

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    Research methodology in montanistic tourism involves the archival research and study of special literature, surface and underground field survey, the analysis of findings of rock fragments, mineral composition, traces of metallurgical processes, fragments of pottery, etc. A separate problem is the study and evaluation of the development of mining and post-mining landscapes, focusing on the entire supply chain of resource industries and their impact on the cultural development of the country

    An intelligent framework and prototype for autonomous maintenance planning in the rail industry

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    This paper details the development of the AUTONOM project, a project that aims to provide an enterprise system tailored to the planning needs of the rail industry. AUTONOM extends research in novel sensing, scheduling, and decision-making strategies customised for the automated planning of maintenance activities within the rail industry. This paper sets out a framework and software prototype and details the current progress of the project. In the continuation of the AUTONOM project it is anticipated that the combination of techniques brought together in this work will be capable of addressing a wider range of problem types, offered by Network rail and organisations in different industries

    Presidential address: Optimization in underground mine planning-developments and opportunities.

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    Presidential address presented at the The Southern African Institute of Mining and Metallurgy Annual General Meeting on 11 August 2016.The application of mining-specific and generic optimization techniques in the mining industry is deeply rooted in the discipline of operations research (OR). OR has its origins in the British Royal Air Force and Army around the early 1930s. Its development continued during and after World War II. The application of OR techniques to optimization in the mining industry started to emerge in the early 1960s. Since then, optimization techniques have been applied to solve widely different mine planning problems. Mine planning plays an important role in the mine value chain as operations are measured against planned targets in order to evaluate operational performance. An optimized mine plan is expected to be sufficiently robust to ensure that actual outcomes are close or equal to planned targets, provided that variances due to poor performance are minimal. Despite the proliferation of optimization techniques in mine planning, optimization in underground mine planning is less extensively developed and applied than in open pit mine planning. This is due to the fact that optimization in underground mine planning is far more complex than open pit optimization. Optimization in underground mine planning has been executed in four broad areas, namely: development layouts, stope envelopes, production scheduling, and equipment selection and utilization. This paper highlights commonly applied optimization techniques, explores developments and opportunities, and makes a case for integrated three-dimensional (3D) stochastic optimization, in underground mine planning.MvdH201

    Otimização do teor de corte e do sequenciamento de minas subterrâneas

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    Orientador: Priscila Cristina Berbert RampazzoDissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação CientíficaResumo: Métodos de lavra subterrânea são aplicados na extração de vários metais e minerais. O planejamento de métodos subterrâneos difere do planejamento de métodos de superfície pelo fato de que não é necessário extrair todas as áreas de produção dentro dos limites econômicos finais para se ter uma sequência factível, ou seja, nos métodos subterrâneos é fisicamente possível que algumas áreas permaneçam não lavradas mesmo estando dentro do limites econômicos finais. O planejamento estratégico é a área central do planejamento de longo prazo de uma mina e visa definir estratégias de escala de produção, métodos de lavra e de beneficiamento mineral, selecionar as áreas que serão lavradas e otimizar a sequência de lavra destas áreas de produção. Para garantir a viabilidade econômica do empreendimento, o planejamento estratégico deve considerar as características-chave dos empreendimentos de mineração, que são: a necessidade de capital intensivo, o longo período de retorno do investimento e o ativo (reserva) limitado. Essas características devem ser consideradas durante o processo de valoração de um empreendimento mineiro, que normalmente é feito através do cálculo do VPL, valor presente líquido. Dentre as principais alavancas do planejamento estratégico, o teor de corte utilizado na seleção dos blocos que serão lavrados e o sequenciamento de mina são os que geram maior número de opções, fazendo com que avaliações de cenários demandem muito tempo e se tornem inviáveis na prática dada a necessidade de respostas rápidas para tomadas de decisão. Neste trabalho, três diferentes modelos matemáticos são propostos para abordar, de forma conjunta, o problema da seleção dos blocos de lavra de uma mina subterrânea e a otimização do sequenciamento destes blocos. Tais modelos consideram o VPL como principal objetivo a ser maximizado e resultam no uso do teor de corte como fator que equilibra as capacidades de produção dos diferentes estágios de um sistema de mineração. A abordagem matemática adapta a modelagem clássica de problemas de sequenciamento considerando os blocos de lavra como tarefas e as atividades de escavação de galerias (desenvolvimento de acessos) e de produção de minério (lavra) como máquinas. Os modelos propostos são testados com base em casos reais, utilizando-se métodos de solução exata e um algoritmo genético. Os resultados computacionais mostram que o algoritmo genético é mais eficiente do que os métodos exatos, sobretudo para instâncias maiores, mais próximas da realidadeAbstract: Underground mining methods are used at the extraction of many metals and minerals. Underground mining planning differs from surface mining planning mainly because, in the first case, it is not necessary to extract all mining blocks within the ultimate economic limits to have a feasible sequence, i.e., it is physically possible to an underground mine to have some areas left \textit{in situ} even if they are inside the ultimate economic limits. Strategic planning is the core area of long-term mining planning and aims to define the scale of production, mining and processing methods, to select areas that will be mined, and to optimize the mining sequence. To guarantee the economic feasibility of a mining asset, strategic planners must also consider the key aspects of mining businesses, which are: capital-intensive requirements, long-term payback, and limited asset (reserves) life. These characteristics must be considered during the valuation process of a mining asset, which is normally conducted through NPV, net present value, calculations. Among the main strategic planning levers, cut-off grades (used at the selection of blocks that will be mined) and the mine sequencing are the ones that generate the greatest number of options. As scheduling multiple scenarios requires a great deal of time, this is infeasible in real situations given the need for quick responses. In this dissertation, three mathematical models are proposed to tackle, at the same time, two problems: the selection of the mining blocks in an underground mine, and the optimization of their sequence. These models consider NPV as the main objective to be maximized and result in using cut-off grades as a factor that balances the main capabilities of a mining system. The mathematical approach adapts classical scheduling models considering mining blocks as jobs; and tunnels excavation (access development) and ore production (mining) activities as machines. The proposed models are tested, with real cases, using exact-solution methods and a genetic algorithm. Results show that the genetic algorithm is more efficient than the exact methods, especially for greater instances that are similar to real problemsMestradoMatematica Aplicada e ComputacionalMestre em Matemática Aplicada e Computaciona

    Underground mine scheduling under uncertainty

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    17 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1016/j.ejor.2021.01.011Underground mine schedules seek to determine start dates for activities related to the extraction of ore, often with an objective of maximizing net present value; constraints enforce geotechnical precedence between activities, and restrict resource consumption on a per-time-period basis, e.g., development footage and extracted tons. Strategic schedules address these start dates at a coarse level, whereas tactical schedules must account for the day-to-day variability of underground mine operations, such as unanticipated equipment breakdowns and ground conditions, both of which might slow production. At the time of this writing, the underground mine scheduling literature is dominated by a deterministic treatment of the problem, usually modeled as a Resource Constrained Project Scheduling Problem (RCPSP), which precludes mine operators from reacting to unforeseen circumstances. Therefore, we propose a stochastic integer programming framework that: (i) characterizes uncertainty in duration and economic value for each underground mining activity; (ii) formulates a new stochastic variant of the RCPSP; (iii) suggests an optimization-based heuristic; and, (iv) produces implementable, tactical schedules in a practical amount of time and provides corresponding managerial insights.National Institute of Occupational Safety and HealthNational Agency for Research and Development (ANID
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