Gold And Copper
Mostrando 1-12 de 49 artigos, teses e dissertações.
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1. Electroanalytical Method for Determination of Trace Metals in Struvite Using Electrochemically Treated Screen-Printed Gold Electrodes
We present an electroanalytical method using square-wave anodic stripping voltammetry on electrochemically-treated screen-printed gold electrodes to the simultaneous determination of lead(II), copper(II) and mercury(II) in struvite (natural fertilizer produced from urine). Electrochemical treatment via cyclic voltammetry of the working electrodes increased s
J. Braz. Chem. Soc.. Publicado em: 2020-09
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2. An integrated pit-to-plant approach using technological models for strategic mine planning of copper and gold deposits
Abstract The strategic mine plan is a crucial step for the success of mining companies, and for its development, it is necessary to use a number of inter-related variables that are usually estimated independently. These variables include operational data that is traditionally isolated in information islands between the different departments in the mine or th
REM, Int. Eng. J.. Publicado em: 2019-06
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3. Avaliação química, ecotoxicológica e genotoxicológica de águas de cavas de mineração a céu aberto
RESUMO Lagos artificiais formados em áreas de mineração a céu aberto são unidades complexas e se constituem em passivos ambientais emergentes advindos da indústria da mineração. Embora estejam aumentando em número em várias partes do globo, são um problema ambiental recente e ainda pouco estudado, especialmente no tocante à qualidade e à toxicid
Eng. Sanit. Ambient.. Publicado em: 21/03/2019
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4. Favorability potential for IOCG type deposits in the Riacho do Pontal Belt: new insights for identifying prospects of IOCG-type deposits in NE Brazil
ABSTRACT: Archean iron oxide-copper-gold (IOCG) deposits have been systematically described in the world class Carajás IOCG district, Amazonian region of Brazil. More recently, several Neoproterozoic (ca 1.13 to 0.96 Ga) IOCG deposits have been identified in the Riacho do Pontal mobile belt situated in the Borborema Province on the northern border of the S�
Braz. J. Geol.. Publicado em: 06/12/2018
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5. Heavy metal tolerance traits of filamentous fungi isolated from gold and gemstone mining sites
ABSTRACT Increased environmental pollution has necessitated the need for eco-friendly clean-up strategies. Filamentous fungal species from gold and gemstone mine site soils were isolated, identified and assessed for their tolerance to varied heavy metal concentrations of cadmium (Cd), copper (Cu), lead (Pb), arsenic (As) and iron (Fe). The identities of the
Braz. J. Microbiol.. Publicado em: 2018-03
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6. Effectiveness acidic pre-cleaning for copper-gold ore
Abstract The presence of copper-bearing minerals is known to bring on many challenges during the cyanidation of gold ore, like high consumption of cyanide and low extraction of metal, which are undesirable impacts on the auriferous recovery in the subsequent process step. The high copper solubility in cyanide prevents the direct use of classical hydrometallu
REM, Int. Eng. J.. Publicado em: 2017-12
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7. RESSONÂNCIA DE PLASMON DE SUPERFÍCIE LOCALIZADO E APLICAÇÃO EM BIOSSENSORES E CÉLULAS SOLARES
Within the last decades, the research on nanoparticles presenting localized surface plasmon resonance has increased constantly. In these materials, the interaction between electrons and incident light results in charge separation, enhancement of the electromagnetic field on the nanoparticles surface and in unique optical properties. Although many metals such
Quím. Nova. Publicado em: 2016-11
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8. Characterization of copper microelectrodes, following a homemade lithography, technique, and gold electroless deposition
We report the fabrication and characterization of copper microelectrodes obtained by a homemade lithography technique and after gold electroless deposition. For the fabrication, planes consisting of arrays of electrodes (black in color) with bow tie shape were designed and printed on a transparent paper (Canson ltd.). Using an embroidery frame with a silk fa
Matéria (Rio J.). Publicado em: 2016-03
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9. Bioleaching of gold, copper and nickel from waste cellular phone PCBs and computer goldfinger motherboards by two
Aspergillus niger strainsIn an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment (WEEE), this research evaluated the bioleaching efficiency of gold (Au), copper (Cu) and nickel (Ni) by two strains of
Aspergillus niger in the presence of gold-plated finger integrated circuits found in computer motherboards (GFIBraz. J. Microbiol.. Publicado em: 2015-09
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10. CARACTERIZAÇÃO DE NANOFIOS DE GERMÂNIO SINTETIZADOS UTILIZANDO COBRE COMO CATALISADOR
This paper presents reliable synthesis of germanium nanowires by the vapor-liquid-solid method using copper as an alternative catalyst to gold, the most commonly used metal. The morphological study showed long range single-crystalline germanium nanowires with diamond structure and diameters ranging from 20 nm to 80 nm and lengths in tenths of a micrometer
Quím. Nova. Publicado em: 2015-07
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11. Síntese, caracterização e atividade fotocatalítica de catalisadores nanoestruturados de TiO2 dopados com metais
Titanium dioxide nanostructured catalysts (nanotubes) doped with different metals (silver, gold, copper, palladium and zinc) were synthesized by the hydrothermal method in order to promote an increase in their photocatalytic activity under visible light. The catalysts were characterized by X-ray diffraction, diffuse reflectance spectroscopy, transmission ele
Quím. Nova. Publicado em: 2013
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12. Processamento de placas de circuito impresso de equipamentos eletroeletrônicos de pequeno porte
A hydrometallurgical process applicable to printed circuit boards of small electrical and electronic devices was developed. This involved three leaching steps (60 ºC, 2 h): 6 mol L-1 NaOH, 6 mol L-1 HCl and aqua regia. NaOH removed the resin and flame retardant that covered the circuit boards. HCl dissolved the most electropositive metals and a small amount
Quím. Nova. Publicado em: 2013