DEMIN - Departamento de Engenharia de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/510

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2001 - 200932010 - 201992020 - 20228

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Autor: search.filters.author.Curi, Adilson

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Agora exibindo 1 - 10 de 20
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    The importance of the economic exploitation plan in the decision making process in mining.
    (2022) Almeida, Wendel Eduardo de; Curi, Adilson; Arroyo Ortiz, Carlos Enrique
    In general, investors evaluate several investment alternatives including, obviously, the possibility of money investment in the banking system. The mineral resource industry is just one of the several options of investment available in the financial market. To select this option, especially for the mining investments, investors require ever more projects with proven financial security and developed by renowned companies. The financial return or potential of the project must be significant to justify the risks inherent to the mining activities. To facilitate the financial analyses of mine projects, in this study is proposed a methodology based on an economic analysis of the Brazilian gold Berimbau mine through an Economic Exploitation Plan - EEP- where a sensitivity analysis of the project cash flow was performed and variations in the ore price, investments (CAPEX - capital expenditure) and operating costs (OPEX - operating expense) were applied. An orthodox scenario with an ore price (gold) of USD 900.00/oz was considered. The results, specific aspects and socioeconomic benefits have confirmed the project’s feasibility.
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    Remediation alternatives for an abandoned gold mine contaminated with mercury in Brazil.
    (2022) Miranda, José Fernando; Lima, Hernani Mota de; Curi, Adilson; Luz, José Aurélio Medeiros da; Destro, Elton
    Heavy metal contamination of soils has generated two major problems, namely, loss of land value and health risk for people near contaminated sites. Studies on soil remediation are typically conducted on a pilot scale under very controlled conditions. This is a misleading approach, once the complexity of the actual biogeochemical soil conditions may causes inefficiency in full scale real-world application. In addition, environmental impacts of remediation practices themselves are often ignored, which may make them unfeasible. In 2002, an occurrence of mercury in an abandoned old gold mine was detected in a rural area of Descoberto, Brazil. In 2014, the State Public Prosecutor required from the responsible State Environment Agency, a remediation project to the area. This study compares alternatives for remediation of the contaminated area. Also a historical approach on mercury amalgamation in gold mining in the region, in order to estimate the amount of mercury remaining in the site. The geochemical characterization of the contaminated area was performed to describe the contamination process. The results were compared with the remediation proposal advocated by the Brazilian Ministry Public, and some alternatives for decontamination of the area were studied. The electrokinetic method has displayed the lowest overall unit cost, between US$ 120.00/t and US$ 260.00/t. The residual Hg concentration after four cycles of the electrokinetic technique was estimated at 1.28 mg (Hg)/kg (soil), slightly higher than the intervention value for agricultural soil, which is 1.20 mg (Hg)/kg (soil).
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    Mine waste sequencing on an iron ore project.
    (2022) Curi, Adilson; Arroyo Ortiz, Carlos Enrique; Casimiro Huayhua, Jorhs Enrique
    Los recursos minerales disponibles en nuestro planeta son finitos, aunque su potencial no sea conocido en su totalidad. El diseño de un proyecto minero, desde las actividades de exploración para conocer el depósito mineral, explotarlo y el cierre de una mina, puede influir la vida útil de la mina. El objetivo de este estudio es evaluar la forma de disposición selectiva de los residuos de una mina de hierro y su posible reutilización en el futuro, destacando su uso y posibles repercusiones en la extensión de su vida útil de una mina de hierro localizada en el Quadrilatero Ferrifero. Recursos y reservas han sido evaluados, así como las fases finales e intermediarias, la secuencia de minado y disposición de residuos. La metodología ha sido empleada en un depósito de hierro brasilero en operación. En donde se pretende demostrar la importancia de evaluar los materiales residuales a fin de prolongar la vida útil del yacimiento mineral.
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    Estimation of mercury released from an abandoned gold mine in Minas Gerais, Brazil.
    (2020) Miranda, José Fernando; Curi, Adilson; Lima, Hernani Mota de
    Mining is very important to the economic, political and social development of the Minas Gerais State in Brazil ever since the time the country became a Portuguese colony in the early 1500s. However, few researches have been conducted to evalu- ate the environmental impacts associated with the mining activity at this time. There are many abandoned mines in Minas Gerais; these are mainly gold mines inherited from the colonial period, which have been considered to represent a considerable en- vironmental liability. However, when a road was constructed in a rural area of the municipality of Descoberto, Minas Gerais, in 2002, a significant amount of mercury was detected in an abandoned gold mine. In 2014, the State Public Prosecutor’s Office found both the State of Minas Gerais and the State Environmental Agency liable and responsible for this occurrence and ordered them to design an intervention project for the contaminated area that involved mine closure. This article provides informa- tion on how mercury contamination occurred and estimates the amount of mercury present in the contaminated area, with the aim of supporting proposals of alterna- tive remediation, monitoring and management therein. This study includes a historical survey of mining operations in the region and a brief history of the use of mercury in amalgamation. Estimations are made of the amount of gold produced and the amount of mercury released into the environment between 1850 and 1892. Results show an estimated mass of 820 kg of mercury contained in soils and sediments within an area smaller than 1 hectare.
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    Non-deterministic load and dump behaviour in mining haul trucks : a case of study.
    (2021) Barbosa, Rodrigo Correia; Arroyo Ortiz, Carlos Enrique; Curi, Adilson
    Complex load and haul cycles in mining are composed of individual steps, whose times could be better described by a statistical distribution than by the average value. In order to evaluate how loading times and dumping times behave, this paper tested a large dataset of loading and dumping times measured at an open pit limestone mine in Brazil against the distributions most commonly used to model these variables, Log-normal and Normal; as well as Gamma, Logistic, Weibull and Exponential distributions. None of the tested distributions provided statistically significant adherence to the data, but it was possible to identify that for most equipment, Logistic and Normal distributions would produce less error on stochastic modelling then the other tested distributions.
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    Impact of bulk density estimation in mine planning.
    (2021) Reis, Celso Henrique Miranda; Arroyo Ortiz, Carlos Enrique; Curi, Adilson; Zangrandi, Marcelo Henrique Damião
    The incorporation of bulk density uncertainty for Mineral Resource and Mineral Reserves (MRMR) steps is of great importance for successful mine planning process. In practice, most mining projects use an average density value for each lithological type of the deposit. However, density determinations require special attention as they directly affect the conversion of volumes to tonnages and ore grades to metal contents. The objective of this study is to measure and minimize the risks associated with the MRMR stages, including the density variability in mine planning. Traditional interpolation techniques in geostatistics were used to represent density spatial distribution in a block model, similarly to those used for grade estimation. This approach was developed and applied at a Brazilian iron ore mine. The results indicate MRMR are underestimated if density uncertainty is not considered. Mine design changes were observed, including 5% impact on the Life-of-mine (LOM) and 2% in Net Present Value (NPV).
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    Environmental and operational benefits through implementing a fleet management system in mining industry.
    (2020) Felsch Junior, Walter Schmidt; Arroyo Ortiz, Carlos Enrique; Curi, Adilson; Gonçalves, Douglas Ramos; Pinto, Alexandro Afonso
    Mining fleet management is fundamental to the transportation infrastructure in a mining nowadays. Several factors influence the success of a new system adoption, such as changes in the project design, operational maturity, direct leadership engagement, and senior management participation. To start with, the main objective of this study is to present the results obtained with the implementation of the Fleet Management System in a mining company located in the Southeast region of Brazil. In this study, the chronology of the implementation of the technology was presented, comparing the operational factors and environmental impacts to the operation results. As a result, there was a 23% increase in the transportation fleet performance, which led to a monthly potential reduction in the emission of 136 tons of greenhouse gases in the atmosphere because of the reduction of the transportation fleet required for ore movement. Furthermore, these gains may be enhanced over the years, expanding its possibilities with the use of new techniques and research.
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    Estimation of mercury released from an abandoned gold mine in Minas Gerais, Brazil.
    (2020) Miranda, José Fernando; Curi, Adilson; Lima, Hernani Mota de
    Mining is very important to the economic, political and social development of the Minas Gerais State in Brazil ever since the time the country became a Portuguese colony in the early 1500s. However, few researches have been conducted to evaluate the environmental impacts associated with the mining activity at this time. There are many abandoned mines in Minas Gerais; these are mainly gold mines inherited from the colonial period, which have been considered to represent a considerable environmental liability. However, when a road was constructed in a rural area of the municipality of Descoberto, Minas Gerais, in 2002, a significant amount of mercury was detected in an abandoned gold mine. In 2014, the State Public Prosecutor’s Office found both the State of Minas Gerais and the State Environmental Agency liable and responsible for this occurrence and ordered them to design an intervention project for the contaminated area that involved mine closure. This article provides information on how mercury contamination occurred and estimates the amount of mercury present in the contaminated area, with the aim of supporting proposals of alternative remediation, monitoring and management therein. This study includes a historical survey of mining operations in the region and a brief history of the use of mercury in amalgamation. Estimations are made of the amount of gold produced and the amount of mercury released into the environment between 1850 and 1892. Results show an estimated mass of 820 kg of mercury contained in soils and sediments within an area smaller than 1 hectare.
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    A gestão participativa dos recursos hídricos no setor mineral brasileiro.
    (2017) Miranda, José Fernando; Figueiredo, Janine Rodrigues; Curi, Adilson; Alameda Hernández, Pedro Manuel
    A água é um recurso mineral de valor inestimável para a economia de qualquer País. A mineração é uma atividade que tem forte dependência da água em seus processos e métodos. Visando a valorização e o controle sustentável de uso da água no território brasileiro foi estabelecida em 1997 a Lei Federal número 9.433 sobre a "Política Nacional de Recursos Hídricos". Esta lei estabelece mecanismos de gestão descentralizada e participativa visando a manutenção da quantidade e qualidade da água num contexto geral. Por este dispositivo legal foram criadas algumas ferramentas de gestão de recursos hídricos, de âmbito nacional, tais como: - o Sistema Nacional de Gerenciamento de Recursos Hídricos; o Enquadramento dos Corpos de Água; a Outorga Pelo Direito de Uso; a Cobrança Pelo Uso e o Sistema de Informações Sobre Recursos Hídricos. Este artigo apresenta os principais pontos da gestão de recursos hídricos relacionados ao setor mineral brasileiro e apresenta um exemplo de aplicação real desta regulamentação num empreendimento mineral nacional.
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    Uso turístico da mina subterránea brasileira de ouro de Passagem (MG).
    (2017) Miranda, José Fernando; Curi, Adilson
    Brasil tuvo varios casos de cierre inadecuado de minas durante su historia. En las últimas décadas, sin embargo, los casos de restauración de las minas, incluyendo un nuevo uso del área, son frecuentes. La principal razón para ello ha sido una legislación más exigente y más actuante. Este artículo describe el caso de la restauración de la mina subterránea cerrada de Passagem en Mariana (MG) para su uso como una estructura de turismo histórico y de aventura. En este estudio de caso se contemplan seis áreas principales de impactos: Impacto en el ambiente físico, biológico y ecológico; impacto en los valores de uso alternativos del área; impacto en la calidad de vida; impacto en los valores culturales y sociales; impacto en el desarrollo económico y sostenible.