Chemical mapping and analysis of electronic components from waste PCB with focus on metal recovery
Autor: | R.A. Mesquita, D. Majuste, R.A.F Silva |
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Rok vydání: | 2018 |
Předmět: |
Environmental Engineering
Materials science Scanning electron microscope General Chemical Engineering Energy-dispersive X-ray spectroscopy Analytical chemistry 02 engineering and technology 020501 mining & metallurgy Grinding Metal Printed circuit board 0205 materials engineering visual_art Electronic component visual_art.visual_art_medium Environmental Chemistry Leaching (metallurgy) Inductively coupled plasma Safety Risk Reliability and Quality |
Zdroj: | Process Safety and Environmental Protection. 120:107-117 |
ISSN: | 0957-5820 |
DOI: | 10.1016/j.psep.2018.09.002 |
Popis: | This paper describes a detailed chemical characterization of connector pins separated from diverse electronic components removed from waste printed circuit boards (WPCB) of computers. Chemical maps by SEM-EDS (Scanning Electron Microscopy - Energy Dispersive Spectroscopy) indicated that the substrates of all connector pins are made by Cu-Sn, Cu-Zn or Cu-Sn-Zn alloys, which are covered by thin Ni and Au layers. The ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry) analysis of the different connector pins revealed that these materials are mostly constituted by Cu (62–88% w/w) and very attractive Au contents were found (up to 1273 g/t). For all pins, intermediate contents of Zn, low contents of Ni, Sn and Pb and very low contents of Pd and Fe were determined. A heterogeneous, 100% metallic sample was prepared by mixing all individual connector pins aiming at contribute to the development of feasible technologies for recovering valuable metals. The mixed sample contains about 73% w/w Cu and 168 g/t Au, which are higher than the contents reported in the literature for samples obtained after grinding assembled or disassembled WPCB. The leaching of the mixed sample without grinding and concentration steps will reduce operating costs and maximize metals recovery avoiding mass losses. |
Databáze: | OpenAIRE |
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