Metal Recovery
Mostrando 1-12 de 110 artigos, teses e dissertações.
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1. PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC a
Quím. Nova. Publicado em: 20/07/2020
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2. Use of Arduino in the Development of a New and Fast Automated Online Preconcentration System Based on Double-Knotted Reactor for the Mn Determination in Tea Samples by Flame Atomic Absorption Spectrometry (F AAS)
In the present paper, an automated online preconcentration system based on the use of two knotted reactors (KR) was developed for Mn determination in tea samples by flame atomic absorption spectrometry (F AAS). The system automation was performed by using four solenoid valves to switch sample streams and reagents. Valves were driven electronically by an inte
J. Braz. Chem. Soc.. Publicado em: 2020-01
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3. Evaluation of Mass Loss in Different Stages of Printed Circuit Boards Recycling Employed in Temperature Controllers
The aim of this work was to evaluate mass loss in each stage of the recycling process for metal recovery from PCBs of controllers and temperature indicators of cold chambers. The stages of process consists of grinding, particle size classification, magnetic and electrostatic separation. It was analyzed 13 kg of PCBs. These PCBs were crushed and ground. The g
Mat. Res.. Publicado em: 02/12/2019
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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. A Sustainable Methodology to Extract Bismuth from Secondary Sources
Bismuth is a critical metal broadly used in cosmetic, medicine and metallurgy. However, its scarcity in Earth’s crust may impair further applications. An alternative is to recover bismuth from secondary sources. In this work, a methodology to extract bismuth from safety valves of discharged gas cylinders is proposed. Extraction and purification of bismuth
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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6. 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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7. Optimización de un procedimiento para la determinación de oro mediante espectrofotometría UV/Vis
ABSTRACT The main objective of the research group is the recovery of valuable metals (contained in PCB’s) such as Cu, Au, Ag, Pt, Pd, etc., by hydrometallurgical alternatives to the current ones used in mining. One of the biggest difficulties that has encountered the research group is the lack of availability of an adequate, simple and reliable quantitativ
Matéria (Rio J.). Publicado em: 19/07/2018
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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. AVALIAÇÃO DOS RESÍDUOS GERADOS DURANTE A DESTRUIÇÃO DE PCBS PELO PROCESSO CATALISADO POR BASE
There are many processes capable of decontamination of polychlorinated biphenyls in several matrixes. The set of inputs, materials, operation conditions and efficiencies are wide. The base catalyzed dechlorination process shows application potential in great scale, mainly due mild chemical reaction conditions and low cost raw materials. The KPEG is a familia
Quím. Nova. Publicado em: 2018-06
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10. The genomes of three Bradyrhizobium sp. isolated from root nodules of Lupinus albescens grown in extremely poor soils display important genes for resistance to environmental stress
Abstract Lupinus albescens is a resistant cover plant that establishes symbiotic relationships with bacteria belonging to the Bradyrhizobium genus. This symbiosis helps the development of these plants in adverse environmental conditions, such as the ones found in arenized areas of Southern Brazil. This work studied three Bradyrhizobium sp. (AS23, NAS80 and N
Genet. Mol. Biol.. Publicado em: 17/05/2018
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11. Applying chemometrics to predict metallurgical niobium recovery in weathered ore
Abstract Niobium metallurgical recovery measures how much of the metal content in the ore is separated in the concentrate after the mineral processing stages. This information can be obtained through laboratory tests with ore samples obtained during drilling. Thereunto, representative ore samples are subjected to tests mimicking the ore concentration process
REM, Int. Eng. J.. Publicado em: 2018-03
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12. Growing Periandra mediterranea on post-mining substrate: native Fabaceae with potential for revegetation of degraded rupestrian grasslands in Brazil
ABSTRACT Recovery of degraded areas of rupestrian grasslands is hampered mainly by the limited knowledge regarding substrate management and the biology of native species suitable for revegetation of these areas. The aim of our study was to examine the establishment and growth of Periandra mediterranea in different textures of lateritic substrate from a minin
Acta Bot. Bras.. Publicado em: 15/01/2018