CHEMICAL AND PHISICAL CHARACTERIZATION OF MEMORY BOARDS FROM OBSOLETE COMPUTERS THROUGH OPTICAL EMISSION SPECTROMETRY AND SCANNING ELECTRON MICROSCOPY
Marcos Paulo Kohler Caldas, Mariana Alves de Carvalho, Viviane Tavares de Moraes, Jorge Alberto Soares Tenório, Denise Crocce Romano Espinosa
Abstract
The combination between the high volume of waste electrical and electronic equipment (WEEE) and the increased planned obsolescence makes it necessary thinking about alternative ways to dispose these wastes, such as recycling followed by metal recovery, without affecting the environment and human health. In order to do so, it is essential understanding the nature of the waste-constituent materials. Printed Circuit Boards (PCB) are important representatives of WEEE, since they are found in most electronic equipment such as computers. PCB heterogeneous composition comprises high metal contents - some of them are precious metals, which represent almost the entire intrinsic value of the board and that justifies applying recycling processes to recover them. The aim of the present study is to investigate the characterization of memory boards from obsolete computers for the subsequent recovery of its precious metals. It was possible to conclude that the memory board mass comprised 18.9% metals, 48.4% ceramics and 32.7% polymers. Cu was the most expressive metal, since it accounted for 13.83% of the board mass. Precious metals such as Ag and Au represented only 0.053% and 0.069% of the board mass, respectively; however, their high market value justifies their recovery.
Keywords
References
1 Fundação Joaquim Nabuco. III Seminário Internacional sobre Resíduos de Equipamentos Eletroeletrônicos, SIREE: cidades sustentáveis e experiências inovadoras na gestão de resíduos de equipamentos eletroeletrônicos. Recife: Porto Digital; 2013.
2 Schluep M, Hagelueken C, Kuehr R, Magalini F, Maurer C, Meskers C, et al. Recycling from e-waste to resources. Paris: UNEP; 2009.
3 Bertuol DA, Veit HM, Bernardes AM, Espinosa DCR, Tenório JAS. Resíduos urbanos tecnológicos: desafios e tendências. Revista Metalurgia e Metais. 2005;61:167-170.
4 Yamane LH. Lixiviação bacteriana de sucata eletrônica: influência dos parâmetros de processo. São Paulo: Associação Brasileira de Metalurgia e Materiais; 2013. p. 50-56.
5 Moraes, VT. Recuperação de Metais a Partir do Processamento Mecânico e Hidrometalúrgico de Placas de Circuito Impressos de Celulares Obsoletos. Escola Politécnica da Universidade de São Paulo (EPUSP), p. 119, 2011.
6 Babu BR, Parande AK, Basha CA. Electrical and electronic waste: a global environmental problem. Waste Management & Research. 2007;25(4):307-318.
7 Luppi TVS. Recuperação de prata a partir de radiografias. In: Anais do 3º Seminário de Tecnologia e Pesquisas Ambientais. SENAI; 2008.
8 Furtado JGC. Estudo de impactos ambientais causados por metais pesados em água do mar na baía de São Marcos: correlações e níveis background. João Pessoa: Universidade Federal da Paraíba; 2007.
9 Domingues TCG. Teor de metais pesados em solo contaminado com resíduo de sucata metálica, em função de sua acidificação [dissertação]. Campinas: Instituto Agronômico; 2009.
10 Gurung M, Adhikari BB, Kawakita H, Ohto K, Inoue K, Alam S. Recovery of gold and silver from spent mobile phones by means of acidothiourea leaching followed by adsorption using biosorbent prepared from persimmon tannin. Hydrometallurgy. 2013;133:84-93. http://dx.doi.org/10.1016/j.hydromet.2012.12.003.
11 Guo J, Rao Q, Xu Z. Application of glass-nonmetals of waste printed circuit boards to produce phenolic moulding compound. Journal of Hazardous Materials. 2008;153(1-2):728-734. http://dx.doi.org/10.1016/j.jhazmat.2007.09.029. PMid:17949900.
12 He W, Li G, Ma X, Wang H, Huang J, Xu M, et al. WEEE recovery strategies and the WEEE treatment status in China. Journal of Hazardous Materials. 2006;136(3):502-512. http://dx.doi.org/10.1016/j.jhazmat.2006.04.060. PMid:16820262.
13 Li J, Lu H, Guo J, Xu Z, Zhou Y. Recycle technology for recovering resources and products from waste printed circuit boards. Environmental Science & Technology. 2007;41(6):1995-2000. http://dx.doi.org/10.1021/es0618245. PMid:17410796.
14 Naseri Joda N, Rashchi F. Recovery of ultra fine grained silver and copper from PC board scraps. Separation and Purification Technology. 2012;92:36-42. http://dx.doi.org/10.1016/j.seppur.2012.03.022.
15 Petter PMH, Veit HM, Bernardes AM. Evaluation of gold and silver leaching from printed circuit board of cellphones. Waste Management. 2014;34(2):475-482. http://dx.doi.org/10.1016/j.wasman.2013.10.032. PMid:24332399.
16 Ewald MR. Equipamentos Eletroeletrônicos – Requisitos para atividade de manufatura reversa.
17 Das A, Vidyadhar A, Mehrotra SP. A novel flowsheet for the recovery of metal values from waste printed circuit boards. Resources, Conservation and Recycling. 2009;53(8):464-469. http://dx.doi.org/10.1016/j.resconrec.2009.03.008.
18 Rochat D, Hagelüken C, Keller M, Widmer R. Optimal recycling for Printed Wiring Boards (PWBs) in India. In: Proceedings of the R’07 World Congress, Recovery of Materials and Energy for Resource Efficiency; 2007; Davos, Switzerland. Davos; 2007.
19 Abrantes R. Reciclagem de placas de circuito impresso: optimização da operação de processamento físico. Lisboa: Instituto Superior Técnico, Universidade Técnica de Lisboa; 2009. p. 97.
20 Oguchi M, Sakanakura H, Terazono A. Toxic metals in WEEE: characterization and substance flow analysis in waste treatment processes. The Science of the Total Environment. 2013;463-464:1124-1132. http://dx.doi.org/10.1016/j.scitotenv.2012.07.078. PMid:22921510.
21 Park YJ, Fray DJ. Recovery of high purity precious metals from printed circuit boards. Journal of Hazardous Materials. 2009;164(2-3):1152-1158. http://dx.doi.org/10.1016/j.jhazmat.2008.09.043. PMid:18980802.
22 Yamane LH, Moraes VT, Espinosa DCR, Tenório JAS. Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers. Waste Management. 2011;31(12):2553-2558. http://dx.doi.org/10.1016/j.wasman.2011.07.006. PMid:21820883.
23 Tu PL, Chan YC, Hung KC, Lai JKL. Growth kinetics of intermetallic compounds in chip scale package solder joint. Scripta Materialia. 2001;44(2):317-323. http://dx.doi.org/10.1016/S1359-6462(00)00590-X.
24 Alam MO, Chan YC, Hung KC. Reliability study of the electroless Ni-P layer against solder alloy. Microelectronics and Reliability. 2002;42(7):1065-1073. http://dx.doi.org/10.1016/S0026-2714(02)00068-9.
25 Yamane LH. Recuperação de metais de placas de circuito impresso de computadores obsoletos através de processo biohidrometalúrgico [tese]. São Paulo: Universidade de São Paulo; 2012. http://dx.doi.org/10.11606/T.3.2012.tde-07062013-154359.
26 Işıldar A, van Hullebusch ED, Lenz M, Du Laing G, Marra A, Cesaro A, et al. Biotechnological strategies for the recovery of valuable and critical raw materials from waste electrical and electronic equipment (WEEE): a review. Journal of Hazardous Materials. 2019;362:467-481. http://dx.doi.org/10.1016/j.jhazmat.2018.08.050. PMid:30268020.
27 Mesquita RA, Silva RAF, Majuste D. Chemical mapping and analysis of electronic components from waste PCB with focus on metal recovery. Process Safety and Environmental Protection. 2018;120:107-117. http://dx.doi.org/10.1016/j.psep.2018.09.002.
28 Veit HM, Bernardes AM, Ferreira JZ, Tenório JA, Malfatti CF. Recovery of copper from printed circuit boards scraps by mechanical processing and electrometallurgy. Journal of Hazardous Materials. 2006;137(3):1704-1709. http://dx.doi.org/10.1016/j.jhazmat.2006.05.010. PMid:16757116.
29 Yamane LH, Moraes VT, Espinosa DCR, Tenório JAS. Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers. Waste Management. 2011;31(12):2553. PMid:21820883.
30 European Union. Directive 2002/95/EC of the European Parliament and of the Council on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (RoHS). Official Journal of the European Union. 2003 Fev 13.
31 Menett RP, Chaves AP, Tenório JAS. Obtenção de concentrados metálicos não ferrosos a partir de sucata eletrônica. Anais do 51 Congresso Anual da Associação Brasileira de Metalurgia e Materiais, vol. 4. Porto Alegre, RS 1996. p. 95.
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