A novel recovery method of copper from waste printed circuit boards by supercritical methanol process: Preparation of ultrafine copper materials

Xiu, Fu-Rong; Weng, Huiwei; Qi, Yingying; Yu, Gending; Zhang, Zhigang; Zhang, Fu-Shen; Chen, Mengjun

doi:10.1016/j.wasman.2016.11.001

Cited by 55 publications

(20 citation statements)

References 39 publications

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“…69 Nunca é demais reforçar que descartar o resíduo eletroeletrônico no ambiente também significa desperdiçar a oportunidade de recuperar partes diretamente recicláveis e metais de alto valor agregado como ouro, prata, cobre etc. 70 A introdução de substâncias tóxicas não antes vistas na natureza, como os retardantes de chama bromados e metais que normalmente se acham na forma de composições minerais não lixiviáveis é uma das consequências do descarte de REEE no ambiente, e uma das características relacionadas ao Antropoceno. 71…”

Section: Figura 2: Placas De Circuito Impresso Em Um Lixãounclassified

“…As PCI são a porção mais economicamente atraente dos EEE. 7,12,13,25,42,70,[123][124][125] Em particular, as PCI de celulares são muito ricas em metais nobres (Figura 9), 108 superando em muito os teores encontrados em fontes naturais.…”

Section: Placas De Circuito Impressounclassified

“…44 Hoje, processos hidrometalúrgicos (mediante o emprego de soluções aquosas) são amplamente empregados para processar a fração metálica das PCI. 70,128,155 Eles têm menor capital inicial, menor impacto ambiental, maiores recuperações em massa e adaptação para escalas menores em relação aos processos pirometalúrgicos (que não empregam solventes e são conduzidos em altas temperaturas), tipicamente encontrados em processos metalúrgicos. 128 A lixiviação deve ser de natureza oxidativa porque os metais estão na forma reduzida, sozinhos ou na forma de ligas.…”

Section: Processamento Da Fração Não-metálica De Pciunclassified

“…123 Menos comum é o emprego de soluções alcalinas (em presença de hidróxido de sódio ou de potássio -NaOH/KOH) de cianetos alcalinos (NaCN e KCN), rota muito utilizada na extração de ouro de minérios contendo baixos teores desse metal nobre. As lixiviações ácidas têm sérias restrições ambientais (geram enormes quantidades de resíduos aquosos corrosivos e sólidos pouco solúveis) 70,81,127,131 e também apresentam risco de acidentes, 159 mas dominam o processamento de frações metálicas pois podem ser controlados e monitorados com facilidade; 128 exigem aparelhagem relativamente simples, muito embora normalmente tenham pouca seletividade. 159 Assim, o desafio é desenvolver rotas ambientalmente mais compatíveis e de custo competitivo, ou melhorar as já existentes.…”

Section: Processamento Da Fração Não-metálica De Pciunclassified

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Waste Electrical and Electronic Equipment: The Anthropocene Knocks on Our Door

Afonso

2018

Rev. Virtual Quim.

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This review describes the technological, environmental, socio-cultural, economical and health challenges due to the waste electrical and electronic equipment. The rate of production of this waste has reached scary levels in the last years, and the level of perception of the populations facing the challenges imposed for their management greatly varies from one country to another. Solutions for waste electrical and electronic equipment are extremely complex, from the establishment of an effective reverse logistics of used products and reverse manufacturing protocols, to the proposal of technologies capable of processing the components of the various electrical and electronic products. Printed circuit boards, cathode ray tubes and liquid crystal displays are the most difficult components to recycle due to their multi-component nature: although they contain high-added value elements in much larger amounts than those of primary sources, they also present metallic components and organic compounds that are highly toxic to health and lead to environmental impacts. Brazil has begun to pay attention to the problem of e-waste relatively recently. Despite ongoing initiatives, the country still has a long way to go until the establishment of a management system that covers all its stages and peculiarities, such as its territorial extension. Waste electrical and electronic equipment is one of the most eloquent symbols of Anthropocene.

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Section: Figura 2: Placas De Circuito Impresso Em Um Lixãounclassified

Section: Placas De Circuito Impressounclassified

Section: Processamento Da Fração Não-metálica De Pciunclassified

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Waste Electrical and Electronic Equipment: The Anthropocene Knocks on Our Door

Afonso

2018

Rev. Virtual Quim.

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“…12,18,19,21 Hydrometallurgical methods are one of the key technologies in metal recycling because they enable a fine separation between chemically-similar metals in small-scale operation. 1,[22][23][24][25][26] The base metals recovery has a substantial impact on the economics of the process due to larger available amount in WPCBs. 27 Moreover, previous leaching of base metals ensures the enrichment of precious metals in the solid residue, making it easier to leach out subsequently.…”

Section: Introductionmentioning

confidence: 99%

Recovery of Lead and Noble Metals After Processing Printed Circuit Boards From Cell Phones by Leaching With Mixtures Containing Hydrogen Fluoride

Silva¹,

Corrêa²,

Gismonti³

et al. 2018

Quim. Nova

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This work examines the leaching of printed circuit boards (PCBs) from cell phones in aqueous solutions containing HF + H 2 O 2 or HF + NaClO under mild experimental conditions. The PCBs were not ground but were previously treated with 6 mol L -1 NaOH at 50 o C for 1 h to remove their soldering mask. , respectively. The processing of the solid residue is also described in detail. It was leached with water at ~90 o C followed by HNO 3aq. at 25 o C. Lead, palladium and silver were recovered in this order, leaving gold as final solid. After 1 h at [35][36][37][38][39][40] o C, 5 mol L -1 HF + 0.3 mol L -1 NaClO mixtures leached the base metals, copper, gold and palladium. Gold was recovered by liquid-liquid extraction with methyl isobutyl ketone. Silver precipitated as chloride. This salt was isolated by leaching with NH 3aq . Loss of fluoride ions (as HF) was below 0.5 wt.% after leaching and handling the solid residue.

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Separation and purification of metal and fiberglass extracted from waste printed circuit boards using milling and dissolution techniques

Tatariants

Yousef

Денафас

et al. 2018

Env Prog and Sustain Energy

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Pulverization operations are extensively used in the recycling of waste printed circuit boards (WPCBs) for liberation of metal and fiberglass in powder shape. The types of liberated metals can vary greatly, for instance it can be copper, tin, lead, aluminum, nickel, gold, palladium, and so forth. However, the obtained metal and nonmetal particles remain contaminated by hazardous material—Brominated Epoxy Resin (BER) what can result in series of environmental and health issues during the further processing. The developed approach was focused on the extraction of uncontaminated copper and fiberglass (which are considered the basic elements that can make up >50% of total WPCB weight) in the form of micro‐particles. To achieve this goal, WPCB samples were cut from areas with high copper concentration while the other components like solder and through‐hole pads (containing other metals) were avoided. At the next step, high energy ball milling was used to grind WPCBs and obtain BER/metal and BER/fiberglass particles. After that, Dimethylformamide (DMF) and ultrasonication were used for dissolution of BER in the powder at a low temperature 50°C, whereas the total treatment time was 4 h and solid to liquid ratio was 1:6 (w/v). Finally, centrifugation was employed to separate the liquid phase (BER/DMF solution) from solid phase (metal and fiberglass particles). The experiments were conducted on five WPCB samples of the same weight that were cut from the five different WPCB models. After the experiments used DMF was regenerated by a rotary evaporator. Ultraviolet‐Visible Spectroscopy, metallographic microscope, Fourier transform infrared spectroscopy, and SEM‐EDS were used to examine the structure of recovered BER, fiberglass, regenerated DMF, and base metal compositions of each sample. The results showed that the metal composition of samples directly depended on WPCB model types. Also, the treatment significantly improved the purity of the extracted fiberglass, therefore it can be used as a high‐purity micro‐filler material for composite applications; the same purification was observed for recovered copper. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018

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A novel recovery method of copper from waste printed circuit boards by supercritical methanol process: Preparation of ultrafine copper materials

Cited by 55 publications

References 39 publications

Waste Electrical and Electronic Equipment: The Anthropocene Knocks on Our Door

Waste Electrical and Electronic Equipment: The Anthropocene Knocks on Our Door

Recovery of Lead and Noble Metals After Processing Printed Circuit Boards From Cell Phones by Leaching With Mixtures Containing Hydrogen Fluoride

Separation and purification of metal and fiberglass extracted from waste printed circuit boards using milling and dissolution techniques

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