Copper Recovery
Mostrando 1-12 de 70 artigos, teses e dissertações.
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1. A SIMPLE GREEN REDUCTION STRATEGY TO SUBSTITUTE CADMIUM IN ANALYTICAL REDUCTION OF NITRATE IN GRIESS–ILOSVAY METHOD
Nitrate is an abundant ion that is present in many industrialized products and the environment. Various analytical methods have been described using the Griess-Ilosvay reagent for the determination of nitrate in different matrices after its reduction to nitrite, in most cases with metallic cadmium as the reducer. This work proposes a new method using aluminu
Quím. Nova. Publicado em: 2021-02
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2. 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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3. Hardening and Dynamic Recovery During Hot Compression Test of Copper Simulated as Viscoplastic Material
The Norton-Bailey equation was used to simulate by finite elements the hardening and dynamic recovery of copper during the hot compression tests. The constants of Norton-Bailey equation were determined from the Voce-Kocks model. The simulation assumes a Mortar Contact with Coulomb friction and axial symmetry. Numerical results were compared with experiments.
Mat. Res.. Publicado em: 05/12/2019
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4. Enrichment of Copper, Lead, and Tin by Mechanical Dry Processing of Obsolete Printed Circuit Board Residues
Waste printed circuit boards (WPCB) residues were mechanically processed to concentrate their metal content aiming to reduce costs of the subsequent recovery of copper, tin, and lead. A fully dry route was proposed to avoid the generation of liquid effluents that would require additional treatment. Firstly, 10.7% of the residue was segregated by magnetic sep
Mat. Res.. Publicado em: 24/10/2019
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5. Potencial antimicrobiano de diferentes retentores intrarradiculares frente a Enterococcus faecalis: uma avaliação in vitro
Resumo Introdução O tratamento endodôntico tem como objetivo erradicar microrganismos bacterianos e fúngicos do canal radicular, ou pelo menos possibilitar sua redução para níveis compatíveis com a saúde do tecido perirradicular, uma vez que, após o tratamento endodôntico, colônias de microrganismos residuais podem estar presentes nos túbulos d
Rev. odontol. UNESP. Publicado em: 23/09/2019
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6. PRÉ-CONCENTRAÇÃO BASEADA NA COPRECIPITAÇÃO USANDO CROMATO DE PRATA COMO CARREADOR PARA DETERMINAÇÃO DE COBRE POR FAAS
In the present paper, a preconcentration procedure based in the coprecipitation of copper by silver dichromate (Ag2CrO4) and consecutive determination by flame atomic absorption spectrometry (FAAS) was proposed. The experimental factors were optimized from application of the Doehlert matrix and the conditions set: chromate concentration 5.8 × 10-4 mol L-1,
Quím. Nova. Publicado em: 2019-01
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7. Damping of Fe-Al Alloy Electrodeposited in an Ionic Liquid
Iron-Aluminium alloys were produced by the electro-deposition of iron-aluminium on a copper substrate. The electro-deposition process was done in the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO. A solution of (0.2 M FeCl2 + 2.75 M AlCl3)/ [Py1,4] TfO was used at a temperature of T=363 K because this mixture is solid at roo
Mat. Res.. Publicado em: 11/10/2018
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8. A study of the metallic silver dissolution with the MEA-NH3-Cu system
ABSTRACT Leaching of silver from minerals has been studied for decades. Recently, research has been focused on the substitution of cyanide (because of its high toxicity) from hydrometallurgical operations. In this sense, the development of alternative-green leaching solutions for the recovery of metallic silver from minerals and urban mines is necessary. In
Matéria (Rio J.). Publicado em: 19/07/2018
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9. Operational conditions of an electrostatic separator for concentrate copper from electronic waste
Abstract Interest in recycling for the recovery of valuable substances, such as precious metals from electric and electronic waste has been increasing year after year due to the large amount present in such waste compared to primary sources. There is environmental concern, since the amount of this kind of waste is increasing due to rapid technological advanc
REM, Int. Eng. J.. Publicado em: 2018-07
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10. Development of a Novel and Simple Electroanalytical Procedure for the Determination of Copper in Biofuel Employing a Sensor Based on Vulcan Functionalized with Carbazone
A novel and simple electroanalytical method for the determination of Cu2+ in biodiesel samples by stripping voltammetric analysis was developed. The method employs a carbon paste electrode (CPE) modified with Vulcan carbon, previouly functionalized with carbazone (CBZ). The CPE/Vulcan-CBZ sensor promoted a significant increase in the analytical signal obtain
J. Braz. Chem. Soc.. Publicado em: 2018-04
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11. 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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12. A Low-Cost Video-Based Reflectometer for Selective Detection of Cu2+ Using Paper-Based Colorimetric Sensors
This paper presents a low-cost reflectometer for selective detection of Cu2+. The reflectometer is based on an emission light source using five light-emitting diodes at different wavelengths and a detector using a webcam. The samples were prepared using a filter paper-based colorimetric sensor with ascorbic acid-based quinoxaline derivative. Video analysis u
J. Braz. Chem. Soc.. Publicado em: 2017-12