208 resultados para Mineração e beneficiamento de urânio


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A time-and-motion study in wood processing of the Eucalyptus harvester's operational cycle was developed. The objective was to evaluate wood harvesters working under several site conditions. The research includes two kinds of harvesters while processing wood to supply paper and cellulose factories, as follows: a machine with twin tires and other one with large tracks, both connected to a different head harvester models. The forestry species were Eucalyptus saligna Smith and Eucalyptus grandis Hill ex Maiden, seven and eight years old, in slope terrains ranging from 0% to 10% degrees, under harvesting systems used by Votorantim and Suzano forestry companies, in São Paulo State, Brazi. Considering all field research, results disclosed that, for some conditions, both machines have shown mathematical correlation between some mechanical wood operation within the processing operational cycle and the saw logs production. All the mathematical correlations were found to express logarithmical models.

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Miners activity results in a significant volume of waste, which is normally deposited in piles. This paper analyzes the behavior of geotextile barrier to control fine soil runoff in a quarry. Two types of geotextile was investigated in order to evaluate the retention efficiency and deterioration after several use.

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Diante da situação de abandono e descaso da área correspondente ao complexo ferroviário de Martinópolis-SP, é criado um espaço que segrega e divide a cidade. Nesse conjunto, destacam-se as antigas instalações da indústria de beneficiamento de algodão, denominada Sociedade Algodoeira do Nordeste Brasileiro (SANBRA), que marca o período histórico da época de sua construção. A partir de estudos referentes ao patrimônio arquitetônico e ferroviário, bem como do desenho urbano, foi determinado o modo de intervir no espaço. Dessa forma, é proposta a requalificação da área deste conjunto. Para tal, serão utilizadas duas escalas. A escala maior se refere à relação dos elementos situados no complexo ferroviário, no qual são propostas diretrizes urbanísticas. Numa escala menor, é proposta a ocupação do edifício com caráter histórico e patrimonial em que se situava os antigos galpões da Sanbra

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This work came in response to the degradation of the landscape by mining. This is the landscape rehabilitation of a quarry off in the city of Laranjal Paulista, the state of São Paulo, which poses environmental and underutilization problems as the area abandonment of consequences. Based on regional diagnostics, urban and landscape study, the project in question is divided into three main areas: environmental recovery, offering public facilities and leisure proposition to adventure tourism. Thus, the Quarry Park - Tourist Complex is a degraded area rehabilitation project from the expansion of leisure options, sports and culture, lacking in the city and the structuring of adventure sports that already occur in the area by a regional public. Thus, one projetual attempt to become a reference in sustainable development

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One of the main challenges in the mining sector at present, related to the optimization of mineral assets, consists in to find the best proportion of each geological material to be mined and homogenized to ensure high productivity and stability in ore processing plants. The stability of a mineral processing plant is factor for achieving operational excellence, as a stable performance of the plants ensures economy and adherence to financial planning businesses. Is already well Know that the feed rate of the processing plants is dependent on the hardness and quality of the ore. Therefore, the ore behavior predictability is the solution to ensure the stability of mineral processing plants. This work was developed in Anglo American Phosphate Brazil Ltda., at the Fazenda Chapadão Phosphate Mine, located in the southeastern portion of the state of Goiás, in the municipalities of Catalão and Ouvidor. The phosphate ore is the result of supergene apatite concentration in the weathering profile of the alkaline ultramafic phlogopitized rocks, intruded by foscoritic and carbonatitic rocks series. The weathering profile has about 100 meters thick and is divided into three basic types, from top to bottom, coinciding with decreasing intensity of weathering: oxidized ore, micaceous ore and weathered rock. In each portion of this weathering profile, mainly near the contacts between these three divisions, are hard materials, cemented by minerals such as apatite, quartz, goethite, monazite and barite. The different features presented by these materials makes to be vital the correct identification, quantification and location of different hard materials in the mine area, to maximize its use. The main objective of this study was to define the type of cementation of hard materials which predominates in each portion of the weathering profile in the mine, as well as their relationship with the protolith. The work involved geological mapping, channel sampling...

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A água é um recurso vital para a existência de todos os organismos vivos, e a captação para uso doméstico, produção agrícola, mineração, produção industrial, geração de energia, atividades de lazer e práticas florestais podem levar à deterioração da sua qualidade, atingindo o ecossistema aquático e também a disponibilidade de água potável disponível para consumo humano. O presente trabalho teve como objetivo monitorar a qualidade da água do Córrego Chumbeadinha no município de Ourinhos-SP, que perpassa pela área urbana da cidade e é desprovido de mata ciliar em quase todo seu percurso, além de sofrer dois represamentos artificiais. O Córrego Chumbeadinha é um afluente de segunda ordem do Rio Paranapanema, percorrendo cerca 4 km de sua nascente até sua foz. Foram realizadas amostragens das seguintes variáveis: Sólidos em Suspensão, pH, concentração de oxigênio dissolvido, condutividade elétrica, temperatura da água, coliformes fecais, transparência da água, além do cálculo do índice de estado trófico, em quatro locais no curso do córrego, de setembro de 2009 a abril de 2010. Dessa forma, o córrego Chumbeadinha nasce com uma qualidade boa, apesar de sofrer forte pressão da expansão urbana, porém os demais pontos foram classificados como eutróficos, sendo registrada a presença de coliformes fecais em todas as amostragens. A falta de vegetação nas margens do lago pode ser a grande causadora da eutrofização, pois os sedimentos não encontram dificuldades para chegar até o curso d'água, assim interferindo diretamente no IET do lago.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Due to the large use of steel in several processes around the world, there is the increasingly concern to find new materials and/or optimization and improvement of the processes, as the need to reduce the cost and a productivity increase in the primary industry, such as the siderurgy. The rolling is the most used mechanical process in the world and therefore is required the development of new tools in high volume and with optimum characteristics to support the market demand. Forged rolls used are for rolling. These rolls have heat treatment that has the purpose to achieve the appropriated mechanical properties to support the variables of the rolling process. The objective of this work is to analyze the hardness profile and the microstructure a tool steel similar to AISI A2, forged in an opened die process and submitted to heat treatment with water-cooling. The results allowed plotting a hardness profile and performing a microstructure analysis, and whereby to confirm that the heat treatment is not a quenching, but it is a material beneficiation by the hardening of superficial layer, since there is no martensitic microstructure. Therefore, this paper provides the support to future studies about the possibility to perform enhancements in this thermal heat made in the rolls produced at Gerdau Plant in Pindamonhangaba

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)