Cassiterite
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. Tin speciation in the blood plasma of workers occupationally exposed in a cassiterite ore processing industry
RESUMO A mineração é uma atividade de alto risco devido aos seus processos perigosos. O estanho (Sn) é obtido do minério de cassiterita e as atividades da mineração expõem os trabalhadores ao metal. A exposição crônica ao Sn pode causar pneumoconiose, gastrointestinal e hematológica entre outros efeitos. Este trabalho avaliou a exposição de tra
Saúde em Debate. Publicado em: 2022
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2. Aquamarine from Massangana batholith, Rondônia State: mineral chemistry and fluid inclusion data
Abstract Beryl is usually found in granite-pegmatite systems. The addition of chromophore elements (V, Cr, Mn, Fe) into the crystalline structure favors color changes in beryl and thus generates some of the world’s expensive gems such as emerald, morganite, heliodor and aquamarine. The Massangana polyphasic batholith is a well-known cassiterite, wolframite
REM, Int. Eng. J.. Publicado em: 2020-09
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3. Geophysical prospection in tin mineral occurrence associated to greisen in granite São Sepé (RS)
Abstract The discovery of new mineral resources involves various research techniques through direct and indirect studies. The geophysical methods are important tools in the detection of deep deposits because they use the contrast between the physical properties of the hosting rocks and the mineralized zone. In this sense, electrical geophysical methods are w
REM, Int. Eng. J.. Publicado em: 2018-04
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4. Synthesis and Microstructural Characterization of SnO2:F Thin Films Deposited by AACVD
In this work, we report the synthesis and microstructural characterization of Tin oxide thin films doped with fluorine for applications such as transparent conductive oxides. Tin oxide doped with fluorine thin films were deposited by aerosol assisted chemical vapor deposition technique onto a borosilicate glass substrate, using a precursor solution of stanni
Mat. Res.. Publicado em: 31/10/2016
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5. DETERMINAÇÃO DE ESTANHO EM AMOSTRAS AMBIENTAIS POR ESPECTROMETRIA DE FLUORESCÊNCIA ATÔMICA
An analytical method to determine tin concentrations in natural samples, by coupling atomic fluorescence spectrometry, hydride generation and flow injection system was developed. The sample digestion procedure and the conditions of hydride generation were fully optimized. The best conditions for the generation of SnH4 were obtained with NaBH4 4% (m v-1) and
Quím. Nova. Publicado em: 2016-07
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6. Uncommon Nb-tantalate from the Cachoeira mine, Araçuaí pegmatite district (Minas Gerais)
Abstract Important spodumene-rich pegmatites have been mined by CBL (Companhia Brasileira de Lítio, Brazilian Lithium Co.) at the Cachoeira mine (northeastern Minas Gerais state) since the 1990's. In this deposit, black platy crystals resembling columbitetantalite are also found; they were analyzed by electronic microprobe as part of the first author's mast
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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7. SnO2 suportado em argila para síntese de Biodiesel / SnO2 Supported on Clay for Synthesis of Biodiesel
Biodiesel production is based on the is transesterification of vegetable oils or animal fat, using homogeneous or heterogeneous catalysts. Wheres, the heterogeneous-based processing presents slower conversions compared to homogenous ones, such processes lead to noncorrosive manufacturing and avoids the occurrence of saponification reactions. Thus, this work
Publicado em: 2009
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8. O plÃsmon da regiÃo de recobrimento da ligaÃÃo quÃmica como ferramenta para caracterizaÃÃo de materiais
Important issues can be raised about the possibility of relations between macroscopic properties of materials and concepts, introduced recently, of the chemical bond overlap polarizability (PR) and the concept of ionic specific valence (VIE). A proposal in which the overlap region of chemical bond is considered as a âplasmon‐likeâ charge distribution
Publicado em: 2009
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9. Evolução quimica e isotopica dos fluidos associados a mineralização de Fe-Cu-Au do deposito Alvo 118, provincia mineral de Carajas - PA / Chemical and isotopic evolution of the fluids from the Alvo 118 Fe-Cu-Au do deposit, Carajas mineral province (PA)
The Alvo 118 iron oxide-copper-gold (IOCG) deposit (170 Mt @ 1,0 wt% Cu, 0,3 g/t Au), together with the world-class Sossego and Cristalino deposits, lie in the southern sector of the Carajas Mineral Province (CMP) along a steeply-dipping, WNW-ESE-striking, 60 km-long shear zone, close to the contact of the Itacaiunas Supergroup metavolcano-sedimentary sequen
Publicado em: 2009
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10. Influência do contra-íon molibdênio nas propriedades do pigmento SnO2: Cr / Influence of the molybdenum counterion in the properties of SnO2:Cr pigments
SnO2 pigments, when doped with chromium, lead to violet or purple colors, depending on chromium oxidation state. There is a need to control the chromophore oxidation state, as Cr(VI) is toxic and carcinogenic, while Cr(III) leads to no risk to living beings. Cr(VI) formation may be avoided with the addition of counterions, that lead to a charge imbalance. In
Publicado em: 2008
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11. DETERMINATION OF SN IN HUMAN MILK BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY / DETERMINAÇÃO DE SN EM LEITE HUMANO POR ESPECTROMETRIA DE ABSORÇÃO ATÔMICA NO FORNO DE GRAFITE
Tin is a metal of natural occurrence which is mainly extracted from the mineral cassiterite, SnO2. Tin may be released to the atmosphere from both natural and anthropogenic sources. In nature, it occurs in both inorganic and organic forms, and the shorter the organic chain associated to the metal, the higher the toxicity of the compound. Organotin compounds
Publicado em: 2008
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12. Metais raros associados ao granito desemborque : estudo mineralogical and chemical study using MEV-EDS / Rare metals associated to desemborque granite : mineralogical and chemical study using MEV-EDS
The Desemborque Granite, a body almost of circular shape, placed in the southernmost part of São Paulo State, has an area of ca. 50 km2. and it is represented by a sienogranite biotite. Its peraluminous features with significant contents of K2O and Na2O, together with low CaO contents, high Fe/Mg ratios, elevated values of SiO2 and trace elements as Zr, Nb
Publicado em: 2007