EM - Escola de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6

Notícias

A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.

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Resultados da Pesquisa

Agora exibindo 1 - 10 de 77
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    Análise estrutural descritiva da mina do Lamego e do seu entorno, Quadrilátero Ferrífero, MG.
    (1998) Carmo, Vitalino Elizeu Ferreira do; Carneiro, Maurício Antônio; Carneiro, Maurício Antônio; Oliveira, Claudinei Gouveia de; Nalini Júnior, Hermínio Arias
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    A kinetic model applied to by injection of lime-based the molten powders.
    (1997) Seshadri, Varadarajan; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Krüger, Paulo Gustavo von
    Akinetic model of hot-metal desulfurization by deep injection of synthetic powdermixtures is presented. The approach takes into consideration the transient contribution due to the particles dispersed in the bulk metal and those located at the bubble-metal interface, the influence of the carry-over slag as well as the volumeand composition of the top slag. Themodel has been utilized to assess the influence of the treatment temperature, rate of injection of powdermixtures, gas flow rate and initial concentration of sulphur over the desulfurization kinetics. In the second part of this study an analysis of the industrial data for injection of powdermixtures using this model is described.
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    Erosion by solid particle impingement : experimental results with cast-iron, laser-treated surfaces.
    (1997) Costa, Adilson Rodrigues da; Vilar, Rui
    The surfaces of cast-iron specimens have been modified by CO2 laser processing in order to enhance their hardness, providing different surfaces for wear behaviour studies. Various laser heat treatmentswere performed in order to generate distinctmicrostruc- tures. Based on previous tests, interaction time and power density usedwere 0.5 s and 0.4 kW/mm2, respectively. Alloyingwith pure Cr allowed microstructure and the chemical composition of the material to be modified in order to attain the desired properties. Chromium^iron carbides, (Cr,Fe)7C3, formed ``in situ'', during laser surface melting, by reaction with carbon of the cast iron, change the wear properties. These carbides were detected by conventional X-ray diffraction. The expected effect of a carbide-rich structure on the erosion behaviour is to decrease themass loss by erosionmechanisms. Erosion was done by SiC erosive blast impin- gement tests. In this method the SiC particles were accelerated in a compressed air stream along a nozzle and projected against the surface to be eroded. After the laser treatment, the erosion behaviour of material was evaluated by measuring the weight loss. The wear test was complemented by SEMmicrostructural observations. Experiments performed in this work show that, in erosion, the mass loss of material does not depend on hardness as proposed by the accepted tribological theories. The worst behaviour was observed for laser-treated surfaces. Embedding of erodent particles plays a decisive role in blast erosion performance of the surfaces studied.
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    Wear behaviour of steel and titanium treated by pulsed ion implantation.
    (1998) Feugeas, J.; Grigioni, G.; Sánchez, G.; Costa, Adilson Rodrigues da
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    Bacias do Espírito Santo e Mucuri.
    (1994) Vieira, Roberto A. B.; Mendes, Marcos P.; Vieira, Paulo E.; Costa, Luciano A. R.; Tagliari, Cláudio Vinicius; Bacellar, Luis de Almeida Prado; Feijó, Flávio Juarez
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    Complexos máfico-ultramáficos do escudo Sul-rio-grandense : revisão com ênfase na geoquímica dos elementos da série 3D de transição.
    (1992) Hartmann, Leo Afraneo; Wildner, Wilson; Remus, Marcus Vinicius Dorneles; Suita, Marcos Tadeu de Freitas
    Os complexos máfico-ultramáficos do Rio Grande do Sul foram reavaliados, com ênfase nos dados disponíveis para elementos químicos da série 3d de transição. Os complexos apresentam geralmente três componentes, quais sejam, ultramáfico (principalmente peridotitos, serpentinitos e xistos magnesianos), máfico e metassomático. Este último componente está bem desenvolvido na maioria dos complexos e foi identificado mas não estudado em detalhe. A suíte gabróica está presente em diversas áreas, tal como Pedras Pretas, e mostra uma química da série 3d de transição desde menos evoluída até mais evoluída, podendo ser classificada da mesma forma que em outras séries do mundo. Os serpentinitos são semelhantes entre si, independente da área avaliada, normalmente mostrando características residuais exceto em Pedras Pretas, onde a química do protólito gabróico foi mantida. Os peridotitos do Cerro da Mantiqueira são harzburgitos e a sua química da série 3d não pode ser distinguida de serpentinitos. Na região do Arroio Cambaizinho, os xistos magnesianos contendo várias proporções de tremolita + clorita + magnetita + ilmenita foram testados em camadas com um a cinco metros de espessura e que apresentam continuidade lateral de afloramento de centenas de metros. Eles mostram química uniforme na mesma banda e parecem corresponder a lavas magnesianas, de afinidade possivelmente komatiítica, metamorfizada na fácies anfibolito. As lavas foram derivadas de um manto enriquecido em elementos LILE ou contaminadas por material crustal.
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    The tectonic evolution of the Quadrilfitero Ferrifero, Minas Gerais, Brazil.
    (1994) Chemale Júnior, Farid; Rosière, Carlos Alberto; Endo, Issamu
    The structural framework of the Quadrilatero Ferrifero is the result of two main deformational events. The first is an extensional event of Palaeoproterozoic age (between 2100 and 1700 Ma, the Transamazonian Event), which resulted in the formation of Archaean granite-gneiss domes and the nucleation of regional synclines in the overlying Rio das Velbas and Minas supergroups strata. Such regional synclines are continuous with each other and are bordered by structural granite-gneiss highs. At the contact between these units, ductile-brittle to ductile extensional shear zones are developed, representing the dislocation surfaces of Archaean blocks. This tectonism is probably related to the evolution of a metamorphic core complex, formed in the hinterland to the west of a Transamazonian collision zone, which structured the Paramirim Craton. The second event is compressive and associated with the closure of the Pan-African/Brasiliano protoocean (650-500 Ma), situated to the east of Quadrilltero Ferrffero (QF). During this event, a west-verging foldandthrust belt (FTB) developed, causing inversion, amplification, translation and rotation of the basinal synclines. The FTB affected mainly the eastern portion of QF and obliterated many of the tectonic features of the extensional event.