Mica
Mostrando 1-12 de 284 artigos, teses e dissertações.
-
1. Characterization of micaceous minerals occurring in phosphate ores in Brazil: emphasis on the interstratified phyllosilicates
Abstract Micaceous minerals were characterized in three phosphatic ores from mines in Western Minas Gerais State, Brazil, all having complex chemical and mineralogical compositions, with emphasis on interstratified phyllosilicates. Knowledge of the relationship between the physical and chemical characteristics of the phyllosilicates contributed to a better u
REM - International Engineering Journal. Publicado em: 2022
-
2. Microbial activity and studies on excavated megalithic micaceous potsherds from Peninsular India
Abstract The abundantly available mica flakes were added in raw materials to manufacture pottery in Central Peninsular India during the early Iron Age (700-300 BCE) for storage and glittering. The micaceous potsherds from the excavated megalithic site of Nagpur were studied for their composition, manufacturing techniques, microstructural features, microbial
Cerâmica. Publicado em: 2021-06
-
3. Caracterização mineralógica das associações de argilominerais em pegmatitos do estado do Rio de Janeiro com enfoque na identificação de depósitos de caulinita e/ou halloysita
Resumo Este estudo reporta a caracterização mineralógica de ocorrências de caulim no estado do Rio de Janeiro, Brasil, com enfoque na identificação de depósitos de caulinita e/ou halloysita. Amostras foram coletadas em 10 pegmatitos de dimensões variadas para estudos de difratometria de raios X, análise química por fluorescência de raios X e micro
Cerâmica. Publicado em: 2020-12
-
4. Pseudosection modeling and U-Pb geochronology on Piranga schists: role of Brasiliano Orogeny in the Southeastern Quadrilátero Ferrífero, Minas Gerais, Brazil
ABSTRACT In the Southeastern Quadrilátero Ferrífero, a package of metapelitic rocks previously attributed to the Archean Rio das Velhas Supergroup crops out in Piranga locality. This study presents the mineral chemistry and U-Pb-Hf zircon geochronology on foliated staurolite-garnet mica schists. Garnet and staurolite index minerals are syn- to post-kinemat
Braz. J. Geol.. Publicado em: 21/10/2019
-
5. Mineralogical and gemological characterization of emerald crystals from Paraná deposit, NE Brazil: a study of mineral chemistry, absorption and reflectance spectroscopy and thermal analysis
Abstract The Paraná deposit, located at Southwestern Rio Grande do Norte state, in Brazil, is one of the few emerald deposits found at Borborema Province. The mineralization occurs in phlogopite schists and actinolite-phlogopite schists associated with pegmatites and albitites within the Portalegre Shear Zone. Unlike other well-known Brazilian emerald depos
Braz. J. Geol.. Publicado em: 22/08/2019
-
6. Depicting the 3D geometry of ore bodies using implicit lithological modeling: An example from the Horto-Baratinha iron deposit, Guanhães block, MG
Abstract The definition of geological domains is essential for mineral exploration and is traditionally done manually, section by section, in a laborious, time consuming and subjective process, to construct a 3D model. The technique referred to as implicit modeling is an option to model deposits in a fast and practical manner. This article presents the litho
REM, Int. Eng. J.. Publicado em: 19/06/2019
-
7. Stratigraphy, petrography and tectonics of the manganese-bearing Buritirama Formation, Northern Carajás Domain, Amazon Craton
Abstract The Buritirama Formation (BF) occurs at the extreme north of the Carajás Province, close to the contact with the Bacajá domain, in the southeastern portion of the Amazon Craton (Brazil). The BF consists of a 40 km long, ca. 3 km wide NW-SE trending structure arranged in four imbricated thrusts that individualize three main stratigraphic units. The
Braz. J. Geol.. Publicado em: 15/04/2019
-
8. Mineralogical and chemical attributes of soils from the Brazilian Atlantic Forest domain
ABSTRACT: The Atlantic Forest is one of the most important and yet the most devastated Brazilian biome, occupying in the past the majority of the East Atlantic Coast. Therefore, a detailed knowledge of the soils near the coastal line influenced by this biome is essential for land use and management of these environments. The aim of this study was to acquire
Sci. agric. (Piracicaba, Braz.). Publicado em: 2019-02
-
9. Dielectric and electrical properties of a mullite/glass composite from a kaolinite clay/mica-rich kaolin waste mixture
Resumo Um compósito mulita/fase vítrea foi preparado por sinterização reativa de uma mistura argila caulinítica/resíduo de caulim rico em mica com 25% em massa de resíduo. A composição de fase, microestrutura, propriedades dielétricas e elétricas do compósito sinterizado a 1400 °C foram avaliadas por difração de raios X, microscopia eletrônic
Cerâmica. Publicado em: 2019-01
-
10. A utilização de análise multicritério na recuperação de minas abandonadas: estudo da intervenção em Portugal
Resumo Tendo em consideração a existência de uma limitação orçamentária que inviabilizava a recuperação de todas as áreas mineiras abandonadas, foi necessário desenvolver um modelo que permitisse escolher quais as minas que seriam objeto de intervenção, tendo em consideração os diferentes fatores de avaliação de seus efeitos externos (no amb
RAUSP Manag. J.. Publicado em: 2018-06
-
11. Identification of Heavy Metals in Crystals of Sand and Silt Fractions of Soils by Scanning Electron Microscopy (SEM EDS/WD-EPMA)
ABSTRACT Studies of heavy metals are concentrate on clay fractions, but coarser fractions of the soil can constitute significant sources of structural forms of heavy metals. The aim of this study was to evaluate the occurrence of heavy metals in the structure of minerals of the sand and silt fractions of soils from three different parent materials (metamorph
Rev. Bras. Ciênc. Solo. Publicado em: 08/03/2018
-
12. Avaliação de novos depósitos de argilas provenientes da região sul do Amapá visando aplicação na indústria cerâmica
Resumo A indústria cerâmica figura entre as cadeias produtivas mais importantes do estado do Amapá, tanto na geração de divisas, quanto na de empregos. O presente trabalho teve como objetivo caracterizar novos depósitos de argilas provenientes da região sul do Amapá, visando aplicações nas indústrias cerâmicas. As argilas inicialmente foram subme
Cerâmica. Publicado em: 2018-03