Recovery of waste printed circuit boards through pyrometallurgical processing: A review

Wang, Huaidong; Zhang, Shuhao; Li, Bin; Pan, De’an; Wu, Yufeng; Zuo, Tao

doi:10.1016/j.resconrec.2017.08.001

Cited by 165 publications

(64 citation statements)

References 93 publications

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“…These elements are present in the different parts and components of the PCBs, i.e. : i) the insulating non-metallic polymer substrate; ii) the 2 http://www.rsc.org/periodic-table metal foil laminated layer on the surface or inside of the substrate and; iii) the Electrical and Electronic (EE) components (integrated circuits, transistors, diodes, resistors, capacitors, coils or transformers) mounted on the substrate, together with sockets, contacts and solders [9]. Fig.…”

Section: A Printed Circuit Boards (Pcbs)mentioning

confidence: 99%

“…Finally, recycling is mandatory taking into account that, on average, the reproduction of consumer electronics needs about 10 times the final weight on raw resources [57]. Furthermore, all this makes the ''urban mining'' an important source of metal resources economically and environmentally beneficial [9]. However, while some metals, like precious metals, have recycling rates that are higher that 50%, others, such as tantalum, indium, gallium, lithium and lanthanides, present poor recycling rates, lower than 1% [30].…”

Section: Recycling and Circular Economymentioning

confidence: 99%

“…Also, a top blowing process, where melting with oxidizing/reducing is carried out, can be used [73]. By rapidly heating up to high temperatures (>1250 • C), followed by a rapid cooling of gases, organic material (for instance brominated organic compounds) is speedy decomposed avoiding dioxins and generation of pollutants [9], [74]. Moreover, lower emissions can be achieved in bath smelter furnaces by using oxyfuel burner (pure oxygen or oxygen-enriched air) as oxidising agent [73].…”

Section: ) Hydrometallurgical Processingmentioning

confidence: 99%

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e-WASTE: Everything an ICT Scientist and Developer Should Know

2019

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Every dazzling announcement of a new smart phone or trendy digital device is the prelude to more tons of electronic waste (e-waste) being produced. This e-waste, or electronic scrap, is often improperly added to common garbage, rather than being separated into suitable containers that facilitate the recovery of toxic materials and valuable metals. We are beginning to become aware of the problems that e-waste can generate to our health and the environment. However, most of us are still not motivated enough to take an active part in reversing the situation. The aim of this article is to contribute to increase this motivation by pointing out the significant problem that e-waste represents and its social and environmental implications. We have chosen this forum in which multidisciplinary researchers in ICT from all countries access on regularly to explain the serious problems we are exposed to when we do not make a responsible and correct use of technology. In this paper, we also survey the composition of contemporary electronic devices and the possibilities and difficulties of recycling the elements they contain. As researchers, our contributions in science enable us to find solutions to current problems and to design more and more powerful intelligent devices. But responsible researchers must be aware of the negative effects that this industry causes us and, consequently, assume their commitment with more sustainable designs and developments. Therefore, the knowledge of e-waste issues is crucial also in the scientific world. Researchers should consider this problem and contribute to minimize it or find new solutions to manage it. These must be the additional challenges in our projects.

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Section: A Printed Circuit Boards (Pcbs)mentioning

confidence: 99%

Section: Recycling and Circular Economymentioning

confidence: 99%

Section: ) Hydrometallurgical Processingmentioning

confidence: 99%

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e-WASTE: Everything an ICT Scientist and Developer Should Know

2019

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“…Previous PCB disassembly can improve subsequent separation and refining operations (Cui and Forssberg, 2003;Veit et al, 2006;Xu et al, 2009); it consists in removing hazardous parts and electronic components from PCBs after solder is removed by thermal or chemical process (Kaya, 2018). ECs dismantling helps to overcome difficulties of subsequent treatments and improves the treatment capacity (Wang et al, 2017), and is one of the most important steps in the recycling process for that reason (Ghosh et al, 2015). Primitive thermally melting solders and manual disassembly have been used to separate of ECs from waste PCBs substrate (Wang et al, 2017); such step is not performed in large scale PCB recycling plants (Hagelüken, 2006), as it constitutes the major cost element and time consuming operation in e-waste recovery technology (Kaya, 2018).…”

Section: Introductionmentioning

confidence: 99%

“…ECs dismantling helps to overcome difficulties of subsequent treatments and improves the treatment capacity (Wang et al, 2017), and is one of the most important steps in the recycling process for that reason (Ghosh et al, 2015). Primitive thermally melting solders and manual disassembly have been used to separate of ECs from waste PCBs substrate (Wang et al, 2017); such step is not performed in large scale PCB recycling plants (Hagelüken, 2006), as it constitutes the major cost element and time consuming operation in e-waste recovery technology (Kaya, 2018). It also causes severe environmental pollution, posing a threat to human health (Guo et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Disassembly of waste printed circuit boards using air heating and centrifugal force

Rubin

Castro

Brandão

2019

REGET

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Waste electrical and electronic equipment is a significant source of material that can contribute to reduce environmental impacts associated to extraction and discard stages; therefore, it is necessary to develop efficient recycling processes for components such as Printed Circuit Boards (PCBs). Current methods for PCB recycling may be optimized by previous disassembly of such components. In the work reported here, an especially designed and manufactured centrifuge was employed to disassemble PCBs from power supplies (PS-PCBs) and memory chips (ME-PCBs) of personal computers (PCs), through combination of hot air flow and centrifugal force. The results showed that the device was capable of separating tin solder, electronic components (EC) and PCB substrate, as long as hazardous components and plastic parts are previously removed. A scanning electron microscope (SEM) with combined energy dispersive X-ray (EDX) analyzer showed that the recovered solder had under 3%wt of contamination; therefore, it can be employed in the production of new soldering material, replacing the more commonly used solder dross. EC recovery rates were up to 94%wt for PS-PCBs and 32%wt for ME-PCBs, and once components such as inductors were not visibly damaged in the process, possibilities of reusing recovered components may be further investigated.

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