Sulphides
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Uso de procesos pirometalúrgicas para la obtención de renio
ABSTRACT Rhenium is a metal that has different obtainment methods. The most used comes from molybdenite roasting. Traditional pyrometallurgical methods like oxidizing roasting are applied, but there are also innovative pyrometallurgical methods as is roasting with carbothermic reduction. This paper presents the behavior of rhenium onto two different roasting
Matéria (Rio J.). Publicado em: 19/07/2018
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2. The Iron Sulfides Crystal Growth from the Halide Melts
A new approach to a single crystals growth of the iron sulfide phases of definite structure and nonstoichiometry is developed and applied. This approach is based on the method of crystal growing from solution melts. This approach is based on the crystallization or recrystallization of iron sulfides from iron sulfide solutions in iron dihalide melts under fix
Mat. Res.. Publicado em: 21/05/2018
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3. Study of aluminum nitride precipitation in Fe- 3%Si steel
For good performance of electrical steels it is necessary a high magnetic induction and a low power loss when submitted to cyclic magnetization. A fine dispersion of precipitates is a key requirement in the manufacturing process of Fe- 3%Si grain oriented electrical steel. In the production of high permeability grain oriented steel precipitate particles of c
Mat. Res.. Publicado em: 11/06/2013
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4. Síntese e estudo das atividades antifúngica e antitumoral de derivados acíclicos e furânicos , -bis-funcionalizados
The present work presents the results obtained from the synthesis and the biological of several bioactive NCEs (NCE= New Chemical Entity), novel a,w-bis-functionalized molecular hybrids which were formed between: organosulfur compounds (sulphides and their corresponding sulphoxides and sulphones) functionalized with tetrazolic rings [Y(CH2)nX-(CH2)nY; Y=tetr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/09/2012
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5. Evolução magmática, alteração hidrotermal e gênese da mineralização de ouro e cobre do Palito, Província Aurífera do Tapajós (PA) / Magmatic evolution, hydrothermal alteration and geneseis of gold-copper mineralization at Palito, Tapajós Gold Province (PA)
The Palito porphyry type copper-gold deposit is located in the central region of the Amazonian craton, in the Tapajós Gold Province (TGP), in an area that is dominated by intermediate to felsic granitic and volcanic rocks of late Paleoproterozoic age. Three lithotypes make up this deposit. The Palito Granite, with porphyritic features, is the host rock for
Publicado em: 2010
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6. Analise da expressão de genes que codificam proteinas transportadoras em Acidithiobacillus ferrooxidans e Acidithiobacillus thioxidans na presença de sulfetos metalicos / Expression analyses of genes that encode for transporter protein in Acidithiobacillus ferrooxidans and Acidithiobacillus thioxidans maintained in contact with metal sulphiides
Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans are acidophilic, chemolitotrophic and mesophilic bacteria found in bioleaching environments. A. ferrooxidans uses ferrous iron and sulphur compounds as an e1ectron donor and A. thiooxidans uses on1y sulphur and sulphur compounds. Both species are aerobic using oxygen as final e1ectron acceptor.
Publicado em: 2008
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7. Identificação e caracterização de genes expressos diferencialmente em Acidithiobacillus ferrooxidans na presença de sulfetos metalicos / Identification and characterization of differentially expression genes in Acidithiobacillus ferrooxidans in the presence of metal sulfides
Acidithiobacillus ferrooxidans is a Gram-negative, mesophilic, acidophilic, chemolithoautotrophic bacterium that obtains energy from the oxidation of ferrous iron, elemental sulfur and reduced sulfur compounds. A. ferrooxidans is one of the most used microorganisms in bioleaching, an industrial process used for the recovery of copper, uranium or gold, fiom l
Publicado em: 2008
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8. Diagramas de Ellingham e de Van't Hoff: algumas considerações
The main subject of this article is to show the parallelism betwen the Ellingham and Van't Hoff diagrams. The first one is a graphic representation of the changes in the standard Gibbs free energy (deltarGtheta) as a function of T and was introduced by Ellingham in 1944, in order to study metallurgic processes involving oxides and sulphides. On the other han
Química Nova. Publicado em: 2007-04
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9. In vitro anti-Candida activity and chemical investigation of leaves and bulbs of Allium tuberosum Rotth. ex Sprengel / Estudo quimico do Allium tuberosum Rottl. ex Spreng biomonitorado pela avaliação da atividade anti-Candida albicans
Frequently used in folk medicine, the genus Allium include more than 600 species founded in several world regions like Europe, North America, Africa and Asia. The most of species is edible and have a aroma and smell characteristics, being algo used as hypocholesterolemic, anticold and antimicrobial. Among theAllium species,A. tuberosum Rottl. ex Spreng (Lili
Publicado em: 2006
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10. Aplicação de técnicas eletroquímicas no estudo da dissolução oxidativa da covelita (CuS) por Thiobacillus ferrooxidans
Among the copper sulphides, chalcopyrite (CuFeS2), covellite (CuS) and chalcocite (Cu2S) are the most important source of minerals for copper mining industry. The acknowledge of behaviour of these sulphides related with bacterial leaching process are essential for optimization procedures. Despite of its importance, covellite has not deserved much interest of
Química Nova. Publicado em: 2002-02
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11. ESTUDO FLUIDODINÂMICO E CINÉTICO DA USTULAÇÃO DE CONCENTRADOS DE SULFETO DE ZINCO EM REATOR DE LEITO FLUIDIZADO / FLUID DYNAMICS AND KINETICS STUDY OF ZINC SULPHIDE CONCENTRATES ROASTING IN FLUIDIZED BED REACTOR
This work presents a fluid dynamics and kinetics study of the roasting of zinc sulphide concentrates at 950¢XC. The data were collected in the literature for experiments carried out in an industrial fluidised bed reactor with an excess of oxygen. The theoretical and experimental characterisation was conducted with the operating variables of the industrial r
Publicado em: 2002
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12. Caracterização da geometria de zonas de alteração hidrotermal - Estudo de caso no deposito aurifero de Brumal, Quadrilatero Ferrifero, Minas Gerais
The Brumal gold deposit is located in the northeastern portion of the Quadrilatero Ferrifero region. It is encIosed within an Archaean voIcano-sedimentary sequence (i.e., Nova Lima Group). Regional host rocks comprise two distinct greenstone assemblages, from bottom to top: (i) mafic to ultramafic volcanics and (i i) cIastic and chemical sediments. At least
Publicado em: 1999