Direct block scheduling technology : analysis of avidity.

This study is focused on Direct Block Scheduling testing (Direct Multi-Period Scheduling methodology) which schedules mine production considering the correct discount factor of each mining block, resulting in the final pit. Each block is analyzed individually in order to define the best target period. This methodology presents an improvement of the classical methodology derived from Lerchs-Grossmann?s initial proposition improved by Whittle. This paper presents the differences between these methodologies, specially focused on the algorithms? avidity. Avidity is classically defined by the voracious search algorithms, whereupon some of the most famous greedy algorithms are Branch and Bound, Brutal Force and Randomized. Strategies based on heuristics can accentuate the voracity of the optimizer system. The applied algorithm use simulated annealing combined with Tabu Search. The most avid algorithm can select the most profitable blocks in early periods, leading to higher present value in the first periods of mine operation. The application of discount factors to blocks on the Lerchs-Grossmann?s final pit has an accentuated effect with time, and this effect may make blocks scheduled for the end of the mine life unfeasible, representing a trend to a decrease in reported reserves

Avaliação de erro no cálculo do volume de sólidos irregulares

Exportado OPUSMade available in DSpace on 2019-08-14T12:30:10Z (GMT). No. of bitstreams: 1 alizeibek_saleimen_nader.pdf: 2071257 bytes, checksum: e95fb24f12217344ba1b30565560f792 (MD5) Previous issue date: 29Esta dissertação de mestrado apresenta, em maiores detalhes, dois métodos bastante utilizados na atualidade para a execução de cálculos de volumes de sólidos irregulares: o método de blocos e sub-blocos e o método de integração vetorial. Inicialmente, discute-se formas para o cálculo de analítico de volumes, apresenta-se suas deficiências para o tratamento de sólidos irregulares e propõe-se o uso de métodos numéricos. Separadamente, estuda-se estes métodos, apresentando, de forma completa, o funcionamento de cada um deles, focalizando-se nas semelhanças e diferenças e dos mesmos. Apresenta-se exemplos visuais de regiões bidimensionais irregulares que possibilitam discussões sobre a estabilidade e o comportamento dos erros frente atranslações, convexidade e não-convexidade. A seguir, calcula-se áreas de regiões representadas por funções, das quais sabe-se o valor exato, através dos dois métodos, apresentando, visualmente, a composição dos vetores e dos blocos e demonstrando analiticamente os cálculos feitos para estas áreas. Insere-se um novo conceito de integração vetorial gaussiana, que faz uso da técnica de integração vetorial aprimorada pela quadratura de Gauss. Apresenta-se descrições detalhadas sobre o funcionamento da quadratura e junção dos métodos. Faz-se estudos comparativos dos métodos utilizando-se sólidos regulares (cilindro e cone) e irregulares, sendo que um dos irregulares foi construído, passo a passo, pela diferença de sólidos regulares conhecidos. Utilizou-se programas existentes no mercadobaseados nos métodos apresentados para a avaliação de erros e tempos de execução. Apresenta-se gráficos e tabelas que expressam os resultados obtidos. Após uma breve discussão sobre a qualidade das informações coletadas, apresenta-se as conclusões e comentários finais e introduz-se de forma bastante sucinta, uma das tecnologias emergentes mais promissoras para o tratamento do problema de cálculo de volume de sólidos irregulares. O desenvolvimento dos algoritmos matemáticos e da tecnologia computacional permitirá que tais avanços tecnológicos alcancem produtos tecnologicamente adequados para o uso indústria mineral.This masters dissertation presents in greater level of details two of the most used methods for performing volume calculation for irregular solids: the blocks and subblocks method and the vector integration method. It starts by discussing forms for the analytical calculation of volumes, presents its deficiencies for treating irregular solids and proposes the use of numerical methods. Separately these methods are studied and their theoretical background is presented in a complete manner denoting their similarities and differences. Visual examples ofirregular bi-dimensional regions are discussed in the light of stability and behaviour of the volumetric errors in situations of translation, convexity and non-convexity. Subsequently, area calculations are performed using the two distinct methods, in regions represented by pre-determined functions whose analytical values are known. The vector and blocks pattern is visually presented and the analytical calculation for these areas is demonstrated. The new concept of gaussian vector integration is introduced where the technology of vector integration is enhanced by the Gauss quadrature technique. Detailed descriptions about the gaussian technique and about the conjunction of the two methods are presented.Comparative studies of the methods using regular solids (cylinder and cone) and irregular solids are executed. One of the irregular solids was created step by step by the difference of known regular solids. Computer software available in the market was used to perform the calculation for each of the methods and the error and time of execution was measured for each case. Graphics and tables with the results that were obtained are presented. A brief discussion concerning the importance of the basic information available in real cases is made followed by the conclusions and final comments. A very brief comment is provided on new promising emerging technologies for the calculation of volumes of irregular solids.The on going development of mathematical algorithms and computer technology will make these technological advances available for products suitable to the mineral industry

Slope monitoring via SSR radar as a geotechnical key performance indicator integrated to the primarily activities of the mineral value chain.

O avanço da tecnologia da informação e da aplicação de computadores na indústria de mineração permitiu a automatização de várias atividades da cadeia de valor mineral (CVM). As atividades da cadeia de valor mineral podem ser divididas em atividades de suporte e em atividades primárias. Os sistemas ERP (Enterprise and Resource Planning) têm fornecido por muitos anos a plataforma para a integração eficiente das atividades de suporte da mineração. No entanto, apesar dos avanços obtidos com a aplicação dos computadores em nichos técnicos específicos, não se conseguiu até o presente momento, integrar efetivamente as atividades primárias da cadeia de valor mineral. As principais razões para isto, são tanto as incertezas existentes no processo produtivo, que diferentemente de outros setores industriais são intrínsecas ao negócio da mineração, quanto as dificuldades para se medir e gerenciar convenientemente os indicadores chave de desempenho (KPIs-Key Performance Indicators), relevantes à cadeia de valor mineral. A medição e controle dos KPIs é fundamental para a quantificação dos eventuais benefícios da aplicação de tecnologia e do potencial de retorno do investimento em recursos humanos e financeiros, necessários à integração das atividades primárias da cadeia de valor mineral. Esta tese não se propõe a integrar a cadeia de valor mineral, mas a demonstrar como a integração da atividade geotécnica da CVM gera benefícios tangíveis, que permitem antever os benefícios de sua completa integração e assim a tese avança a um ponto do controle geotécnico que é o monitoramento da estabilidade de taludes em minas em operação, para demonstrar que a aplicação de metodologias de monitoramento e controle adequadas, impactam positivamente nos KPIs e consequentemente nas atividades da cadeia de valor mineral, relacionadas a eles. O objetivo desta tese é também o de comprovar a importância do monitoramento eficaz dos KPIs para a integração das atividades geotécnicas da cadeia de valor mineral exemplificando seu impacto na eficiência, qualidade e economicidade dos processos envolvidos e assim, comprovar a eficaz possibilidade de integração destas atividades da cadeia de valor mineral e a possibilidade de extrapolação da integração para o restante da mesma. Neste sentido o trabalho desenvolve-se primeiramente no intuito de determinar os principais KPIs controlados em algumas das mais importantes empresas de mineração brasileiras. Pela correta identificação das métricas e do contexto gerencial em que estes estão inseridos é possível demonstrar a importância e o impacto de seu mapeamento e medição para a gestão efetiva do negócio da mineração. Uma nova tecnologia de monitoramento de taludes que faz uso de equipamentos de radar imageadores é apresentada e explicada, assim como vários exemplos de sua utilização ao redor do mundo são descritos, ressaltando-se os resultados obtidos e sua influência na medição e gerenciamento dos KPIs envolvidos. Finalmente, uma nova metodologia escalonada e com pontos de decisão é proposta para a integração da cadeia de valor mineral e aplicada a dois projetos desenvolvidos pelo autor, que são apresentados e discutidos para demonstrar e comprovar os benefícios econômicos advindos de sua aplicação. Para esses projetos, o autor planejou e executou a coleta de dados, procedeu a suas análises, avaliou seus impactos econômicos e comprovou a relevância do estudo realizado.The advance of information technology and computer application to the mining industry has allowed the automation of several activities of the mineral value chain (MVC). The activities of the mineral value chain can be divided in support and primarily activities. ERP (Enterprise and Resource Planning) systems have provided, for many years, the platform for the efficient integration of the support activities in mining. Despite all the advance gathered with the application of computers to specific technical niches, the effective integration of the primarily activities of the mineral value chain has not been obtained to date. The main reasons for this fact are the uncertainties existent in the production process that differently from other industrial sectors, are intrinsic to the mining business, as well as the difficulties to measure and manage the key performance indicators (KPIs) that are relevant to the mineral value chain. The measurement and control of KPIs is fundamental for quantifying the eventual benefits of the application of technology and the potential for the return of the investments in human and financial resources, needed to integrate the primarily activities of the mineral value chain. This thesis is not aimed at integrating the mineral value chain, but to demonstrate how the integration of the geotechnical activity of the MVC generates tangible benefits that allow foreseeing the benefits of its complete integration, so this thesis reaches a point of the geotechnical control that is the slope stability monitoring of operational mines, in order to demonstrate that the application of adequate methodologies of monitoring and control, impact positively on the KPIs and consequently on the activities of the mineral value chain related to them. The objective of this thesis is also to prove the importance of the effective monitoring of KPIs for the integration of the geotechnical activities of the mineral value chain and its impact in the efficiency, quality and economics of the processes involved, in order to prove the effective possibility of the integration of this activity of the mineral value chain thus demonstrating the possibility to extrapolate the integration results to the remaining chain inter-activities. In this sense, the work is developed primarily with the aim of determining the main KPIs that are controlled in some of the most important Brazilian mining companies. Through the correct identification of the metrics and management context in which they are inserted, it is possible to demonstrate the importance and impact of their mapping and measurement for the effective management of the mining business. A new technology for slope monitoring that uses imaging radar equipment is presented and explained as well as several examples of its utilization around the world are described, emphasizing the results obtained and their influence for the measurement and management of the involved KPIs. Finally, a new staggered methodology, with decision points is proposed for the integration of the mineral value chain and applied to two projects developed by the author, which are presented and discussed in order to demonstrate and to prove the economic benefits obtained from its application. For these projects, the author planned and executed the data collection, data analysis, economic assessment and proved the relevance of the work performed

A Case Study of Incorporating Variable Recovery and Specific Energy in Long-Term Open Pit Mining

Integrated Optimization can find optimized solutions for a project to define open pit and mine scheduling with greater reliability. This work aims to demonstrate how the insertion of geometallurgical variables can significantly change the financial return of a project. Two geometallurgical variables are considered in mine planning simulations. Specific energy corresponds to the energy consumed in the comminution of the ore, and process recovery measures the percentage of metal incorporated into the product. Three scenarios were developed considering an iron ore deposit. In the Base Case (BC) scenario, the recovery was fixed, and the specific energy of comminution was not considered. GeoMet1 considers the variable recovery varying for each block. GeoMet2 considered both recovery and specific energy as variables varying for each block. GeoMet1 and GeoMet2 presented Net Present Value (NPV), respectively, as 3.68% and 13.57% lower than the BC. This overestimation of the BC results can be viewed as an optimistic case of mine planning that is very common in the mining industry. These results show that the use of specific energy and recovery variables is fundamental to obtaining more reliable mine planning

Direct block scheduling under marketing uncertainties

Abstract Mineral projects are composed of geological, operational and market uncertainties, and reducing these uncertainties is one of the objectives of engineering. Most surveys assess the impact of geological and operational uncertainties on the mining planning. The objective of this work is to study the impact of market uncertainty on the mineral activity. The influence of iron ore price simulation on mining sequencing will be evaluated. The price of iron ore has random behavior that is best represented by the Geometric Brownian Movement system. This study analyzed the historical series of iron ore in order to determine the percentage volatility and drift. Traditionally, a constant and deterministic price is used for the ore mined in all periods of a mineral project. The direct block scheduling methodology was adopted because it is able to apply the appropriate financial discount factor to the simulated probabilistic price. The proposed methodology was able to quantify the market uncertainty

Direct block scheduling technology: Analysis of Avidity

Abstract This study is focused on Direct Block Scheduling testing (Direct Multi-Period Scheduling methodology) which schedules mine production considering the correct discount factor of each mining block, resulting in the final pit. Each block is analyzed individually in order to define the best target period. This methodology presents an improvement of the classical methodology derived from Lerchs-Grossmann's initial proposition improved by Whittle. This paper presents the differences between these methodologies, specially focused on the algorithms' avidity. Avidity is classically defined by the voracious search algorithms, whereupon some of the most famous greedy algorithms are Branch and Bound, Brutal Force and Randomized. Strategies based on heuristics can accentuate the voracity of the optimizer system. The applied algorithm use simulated annealing combined with Tabu Search. The most avid algorithm can select the most profitable blocks in early periods, leading to higher present value in the first periods of mine operation. The application of discount factors to blocks on the Lerchs-Grossmann's final pit has an accentuated effect with time, and this effect may make blocks scheduled for the end of the mine life unfeasible, representing a trend to a decrease in reported reserves

Direct block scheduling under marketing uncertainties

<div><p>Abstract Mineral projects are composed of geological, operational and market uncertainties, and reducing these uncertainties is one of the objectives of engineering. Most surveys assess the impact of geological and operational uncertainties on the mining planning. The objective of this work is to study the impact of market uncertainty on the mineral activity. The influence of iron ore price simulation on mining sequencing will be evaluated. The price of iron ore has random behavior that is best represented by the Geometric Brownian Movement system. This study analyzed the historical series of iron ore in order to determine the percentage volatility and drift. Traditionally, a constant and deterministic price is used for the ore mined in all periods of a mineral project. The direct block scheduling methodology was adopted because it is able to apply the appropriate financial discount factor to the simulated probabilistic price. The proposed methodology was able to quantify the market uncertainty.</p></div

Analysis of the impacts of slope angle variation on slope stability and NPV via two different final pit definition techniques.

The traditionally and widely used Lerchs-Grossmann algorithm presents well-known limitations that newer propositions attempt to overcome. The direct block schedule (DBS) methodology, which has gained relevance with computational advances, obtains the final pit as a natural result of production sequencing, different from Lerchs-Grossmann-based algorithms. This process flow applies constraints in the final pit definition stage attempting to provide a more realistic result and to minimize risks. Slope instability is a common and inherent risk to open pit mining and may affect the project's net present value (NPV). A study of the impacts of slope angle variations on safety indexes and final pit NPV provides an auxiliary tool for the overall slope angle definition process. This article presents a case study in which the effects of variations of the overall slope angle on the safety factor (SF) and project NPV were analyzed. A total of 25 pits were generated by each studied final pit definition methodology, and each pit had the sections with the varied slope angles analyzed in the stability assessment, resulting in a total of 150 slopes analyzed. A comparison between the results obtained by the two different methodologies implemented in commercial software is presented. The results show no relationship between the NPV and the overall slope angle using the DBS methodology. An analysis of the results for each geotechnical sector obtained by the traditional methodology was conducted and may contribute to the trade-off analysis between the best slope angle to achieve a reasonable SF and the maximum NPV

Direct block scheduling technology: Analysis of Avidity

<div><p>Abstract This study is focused on Direct Block Scheduling testing (Direct Multi-Period Scheduling methodology) which schedules mine production considering the correct discount factor of each mining block, resulting in the final pit. Each block is analyzed individually in order to define the best target period. This methodology presents an improvement of the classical methodology derived from Lerchs-Grossmann's initial proposition improved by Whittle. This paper presents the differences between these methodologies, specially focused on the algorithms' avidity. Avidity is classically defined by the voracious search algorithms, whereupon some of the most famous greedy algorithms are Branch and Bound, Brutal Force and Randomized. Strategies based on heuristics can accentuate the voracity of the optimizer system. The applied algorithm use simulated annealing combined with Tabu Search. The most avid algorithm can select the most profitable blocks in early periods, leading to higher present value in the first periods of mine operation. The application of discount factors to blocks on the Lerchs-Grossmann's final pit has an accentuated effect with time, and this effect may make blocks scheduled for the end of the mine life unfeasible, representing a trend to a decrease in reported reserves.</p></div