DEMIN - Departamento de Engenharia de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/510
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Item Application of optimized models through direct block scheduling in traditional mine planning.(2018) Campos, Pedro Henrique Alves; Hori, Carla Eponina; Morales, N. M.Many papers have been published by the scientific community on the development of techniques that use direct block scheduling (DBS) to solve open pit production scheduling problems, and have compared the results obtained with DBS to those obtained with conventional methods for mine planning. The most significant advantage of using DBS is the possibility of maximizing the economic value to each project. However, until recently, the computational complexity of DBS has prevented it from being used to solve problems on an industrial scale, where there are a large number of mine blocks to deal with and many constraints. While much research has already been conducted and many new tools and algorithms have been developed to solve this global open pit production-scheduling problem, this article proposes the use of optimized models obtained through DBS as part of the conventional medium-term planning methodology to take advantage of its benefits without being hindered by its limitations. Three different approaches to medium-term planning were compared. First, a renowned software package that is used in the mineral industry was used to execute conventional medium-term scheduling. Then, DBS was used to perform the same task. Finally, a combination of DBS and conventional scheduling was tested. Using the results provided by DBS, sectorization of specific areas was included in the conventional methodology to guide the scheduling and thus allow this combination to produce real benefits, even for large projects.Item Direct block scheduling under marketing uncertainties.(2018) Burgarelli, Hudson Rodrigues; Souza, Felipe Ribeiro; Nader, Alizeibek Saleimen; Torres, Vidal Félix Navarro; Câmara, Taís Renata; Arroyo Ortiz, Carlos Enrique; Galery, RobertoMineral 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.Item Incorporation of geological uncertainty in pit optimization with geostatistics simulation.(2017) Souza, Rafael Alvarenga de; Cabral, Ivo EyerRisk mapping processes in mine planning and ore recovery are constantly used in the mining industry to increase decision making certainty based on the available information. However, it is not possible to predict the risk behavior in all of the project's boundary conditions and small variations in some of these conditions can cause a great impact on its financial return. Among the countless uncertainties existing in a mining project (operational, costs, market change), many authors define the geological uncertainty as the most critical one, capable of influencing the success of the project. Measurement and evaluation of the geological uncertainty of a mine planning project is crucial because the calculated risk can be translated into a financial risk of the project. This article presents a possible way to consider the geological uncertainty in the pit optimization step by using sequential Gaussian simulation. The results obtained from the case study on a copper deposit results in a simple procedure with significant increase in reliability for the project.Item Analysis of the economic feasibility of a mining project due to the presence of natural underground cavities.(2015) Aquino, Iure Borges de Moura; Lima, Hernani Mota deThe legislation for the protection and conservation of caves is recent in Brazil. In 2008, the Decree 6.640 was enacted and in 2009, the Normative Instruction Nº 2 by the Brazilian Environment Ministry (MMA, Portuguese acronyms) was published. Mining operations cause a significant impact on the caves when they are present in or next to the mineral body. The impacts include the suppression of cavities and impacts on physical and bio-speleological stability of the caves. On the other hand, the actual legislation causes a significant impact on the mineable reserves when cavities are pres¬ent. This article aims to assess the impact of the natural cavities on the feasibility of a mining project, based on the federal legislation, as well as to propose alternatives to combine mining activity with cave protection. For this research, three scenarios of open pit for a hypothetical ore body were considered for the assessments. This paper presents the results achieved for the three and comments on the necessity of researches to conciliate the conservation of the natural underground cavities with the mining activities.Item Estimate of hourly productivity applied to elaboration and implementation of mining plans.(2014) Rodovalho, Edmo da Cunha; Cabral, Ivo EyerPara elaboração de planos de lavra, é necessário adotar parâmetros de produtividade horária dos equipamentos disponíveis para sua execução. Esses equipamentos devem estar em sincronia com a capacidade produtiva das operações unitárias de lavra mineira: perfuração de rocha, desmonte, carregamento e transporte. Esse estudo trata da estimativa de índices de produtividade horária das operações de carregamento e transporte com a utilização de regressões múltiplas. Através da utilização da base de dados do sistema de gerenciamento operacional de uma mina, foram geradas equações que explicam o ciclo produtivo de cada um dos equipamentos de carga e das frotatransporte. Conhecendo-se o comportamento das principais variáveis que exercem influência na produtividade horária, foi possível estimar esse índice e garantir alta exequibilidade para o plano de lavra, pois os índices obtidos foram muito próximos dos reais. A formulação do modelo foi realizada de forma simples, utilizando-se de conceitos estatísticos e de ferramentas computacionais, sendo o modelo sustentado por uma boa correlação entre as variáveis. Esse fator foi decisivo para que esse estudo obtivesse bons resultados na execução dos planos de lavra estudados.