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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3 resultados
Resultados da Pesquisa
Item Technological characterization of metapyroxenite of the Córrego dos Boiadeiros Formation, Nova Lima (MG), Brazil.(2021) Ferreira, Bruno Trindade; Santos, Maristella Moreira; Lima, Rosa Malena Fernandes; Brito, Hermando; Carmignano, Ottavio Raul Domenico RibertiRocks and industrial minerals are raw materials employed in the production of a wide variety of products, used by modern society. The same mineral or industrial rock can have several applications, depending on their physical, mineralogical and chemical characteristics. The present study had as its objective, the technological characterization of a metapyroxenite sample, belonging to the Córrego dos Boiadeiros body in the Quadrilátero Ferrífero, MG (Brazil) in order to verify its possible industrial applications. For this research study, X-ray fluorescence chemical analyzes were performed, which determined the following oxides: 0.06% TiO2, 8.2% Fe2O3, 24.1% MgO, 2.1% Al2O3, 48.7% SiO2 and 1.8% CaO. In the mineralogical characterization by X-ray diffraction, optical microscopy, SEM / EDS and thermogravimetry, the following minerals were identified: antigorite, chlorite, chromite, ilmenite, magnetite, rutile, talc and tremolite. For the preliminary concentration tests, the material used (-147μm) presented 32% of the particles in the fraction -37μm with d50 in 74μm. The 3575 Gauss magnetic field and the particle size fraction -74μm generated a mass recovery of 96.4% and a whiteness of 61.9% for the non-magnetic product. Although no talc enriched products were generated by preliminary magnetic separation tests, the non-magnetic products presented specifications for the following applications: paper (wallpaper and packing), insecticide and fertilizers.Item Purificação de resíduos de oficina de artesanato em pedra-sabão por flotação e alvejamento químico.(2011) Rodrigues, Michael Leonardo Marques; Lima, Rosa Malena FernandesNa região de Ouro Preto-MG, existem diversas oficinas de artesanato em pedra-sabão. Nessas oficinas, o processo de fabricação de panelas e objetos de adorno, produz uma grande quantidade de resíduos, que, normalmente, são depositados nas proximidades das oficinas, sem nenhuma forma de controle. Esse trabalho teve por objetivo recuperar o talco contido na fração granulométrica abaixo de 74μm desses resíduos através de purificação por flotação e alvejamento químico com HCl. Entre as variáveis estudadas na flotação, apenas a porcentagem de sólidos e a dosagem de espumante se mostraram significativas com relação às variáveis-respostas: recuperação mássica e alvura. Nesse processo, produziu-se um concentrado com alvura (ISO) de 68,56% e com composição química que está de acordo com as especificações de tinta (espalhador) e papel (carga). Após alvejamento químico do concentrado de flotação, foram obtidos alvura (ISO) de 84,0% e teores químicos que estão dentro das especificações da indústria de plásticos (carga e reforço) e plásticos antiaderentes.Item Cleaner production of soapstone in the Ouro Preto region of Brazil : a case study.(2012) Rodrigues, Michael Leonardo Marques; Lima, Rosa Malena FernandesSoapstone is a metamorphic rock that is used for ornamental and construction purposes. Rock recovery during the exploitation process is low. Quarries in the state of Minas Gerais in Brazil sell small and lowquality blocks to artisans, who produce pans and souvenirs. This activity constitutes the main economic activity in several places within the Ouro Preto region, such as Santa Rita. Soapstone artisan workshops produce a large quantity of powder (approximately 10e15% rock recovery), which is discarded carelessly, often causing environmental problems. The objective of this study was to characterise and purify soapstone powder from the workshop of an artisan who works exclusively with rocks from Bandeiras-Santa Rita de Ouro Preto in order to identify potential applications for the residues and purified products. First, the mineralogical composition was determined by X-ray diffractometry, the size distribution was determined by sieving and the chemical composition of the residue was determined by inductively coupled plasmaeoptical emission spectroscopy (ICP-OES). Next, purification tests were performed by magnetic separation for fraction sizes larger than 74 mm. Fraction sizes smaller than 74 mm were purified by flotation and leaching with hydrochloric acid. This research shows that it is possible to recover almost all residues of both small and large size distributions for use as insecticide filler. In addition, it is possible to recover 100% and 96% of fraction sizes larger and smaller than 74 mm, respectively, for use in the paper industry (wallpaper and packaging). For more valuable applications, it is necessary to leach the purified material from flotation using hydrochloric acid. In addition to decreasing the environmental impact of soapstone powder discharge, it is possible for soapstone artisans to sell this powder for a profit, whether it is purified or not.