Sulfides
Mostrando 1-12 de 102 artigos, teses e dissertações.
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1. Geophysical and structural survey in copper occurrence located in the northern region of the Camaquã basin (RS)
Abstract The geophysical diagnosis of mineral deposits can be extremely useful in detailing mineralized zones and is a strategy for direct sampling by probing holes for content analysis. This study involves the combined use of Electrical geophysical methods (DC resistivity and Induced Polarization), geological recognition and structural field analysis, with
REM, Int. Eng. J.. Publicado em: 2021-06
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2. Synthesis and Antioxidant and Antimicrobial Properties of β-Hydroxy Sulfides, Sulfoxides, and Sulfones Derived from Cardanol and Glycerol Derivatives
Natural and synthetic sulfur-bearing organic compounds have many applications in medicinal chemistry. This article reports the preparation of amphiphilic β-hydroxy sulfides, sulfoxides, and sulfones derived from cardanol and glycerol. Thiolysis of cardanol epoxide 3 with various thiols (4a-4j) in ethanol or water yielded the corresponding β-hydroxy sulfide
J. Braz. Chem. Soc.. Publicado em: 2020-12
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3. Effective density concentration in refractory gold ore for characterization purposes
Abstract This article evaluates the efficiency, benefits and limitations of pre-concentration by density separation for process mineralogy studies of low-grade gold ore. The pre-concentration by density aims to generate a product with a high content of gold and to maximize the number of gold-bearing particles characterized, thereby increasing the representat
REM, Int. Eng. J.. Publicado em: 2020-12
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4. Mineralogical characterization of copper lateritic ore from the Furnas deposit - Carajás, Brazil
Abstract Furnas is a small and not well-known copper sulfide deposit in the northern Carajás mineral province (Pará State, Brazil). Mineralogical and geochemical studies were performed on three weathered samples in order to verify the presence of copper in the lateritic minerals. According to these Cu-bearing minerals (malachite, e.g.), the weathered ore c
REM, Int. Eng. J.. Publicado em: 2020-09
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5. An Overview of the Photocatalytic H2 Evolution by Semiconductor-Based Materials for Nonspecialists
The solar-to-chemical energy conversion is promising to tackle sustainability challenges toward a global future. The production of H2 from sunlight represents an attractive alternative to the use of carboniferous fossil fuels to meet our energy demands. In this context, the water splitting reaction photocatalyzed by semiconductors that can be excited under v
J. Braz. Chem. Soc.. Publicado em: 2020-02
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6. Long-term behavior of mortars produced with sulfide-bearing aggregates
ABSTRACT The variety of sulfides (inorganic compounds formed by combining sulfur with a metal element) presented in earth crust is not small, which makes it difficult to avoid the use of sulfide-bearing aggregates in the concrete, especially in places where another source of material is non-existent or economically impracticable, as is the case of dams. With
Matéria (Rio J.). Publicado em: 25/11/2019
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7. Long-term behavior of mortars produced with sulfide-bearing aggregates
ABSTRACT The variety of sulfides (inorganic compounds formed by combining sulfur with a metal element) present in earth crust is not small, which makes it difficult to avoid the use of sulfide-bearing aggregates in the concrete, especially in places where another source of material is non-existent or economically impracticable, as is the case of dams in Braz
Matéria (Rio J.). Publicado em: 10/06/2019
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8. Precipitación de uranio a partir de licores alcalinos
ABSTRACT In Argentina there is uranium with abundant organic matter and variety in quantity of sulfides and carbonates which act as cement or sealing joints. The latter minerals modify directly the choice of metal leaching process for the concentration of uranium. The most beneficial selected process turns out to be the alkaline leaching. Once this process h
Matéria (Rio J.). Publicado em: 19/07/2018
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9. 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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10. UM ESTUDO TERMODINÂMICO DA CORROSÃO DOS AÇOS CARBONO PELO SULFETO DE HIDROGÊNIO - EXPLORANDO CONCEITOS DE EQUILÍBRIO QUÍMICO
This study addresses an inherent problem to the oil and natural gas exploration and production industry, the corrosion of pipes and tanks by H2S. H2S with water emulsified in the oil or H2S with the water vapor mixed in the gas, they make the acid environment leading to corrosion. This is commonly manifested by the formation of insoluble sulfides on the surf
Quím. Nova. Publicado em: 2018-05
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11. 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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12. Efeito da incorporação de agregados com alto teor de sulfetos nas propriedades mecânicas e microestruturais de concretos com cimento de escória
ABSTRACT The mineralogical change in the sulfides present in many aggregates can affect their stability, which may undermine the performance of the concrete. This is a complex process and there is limited research in this area. In this study, we examined the influence of aggregates containing a high sulfide content on the performance of concrete containing s
Matéria (Rio J.). Publicado em: 10/08/2017