Aplicação de planejamentos experimentais multivariados à lixiviação de cobre presente em placas de circuito impresso
Applying multivariate experimental design to copper leaching from printed circuit boards
Rodrigo Ferreira Gomes, Matheus Mello Pereira, Versiane Albis Leão
Resumo
O volume de Resíduos de Equipamentos Elétricos e Eletrônicos (REEE) gerados no mundo em 2018 foi de 50 milhões de toneladas. Cerca de 2% desses resíduos são Placas de Circuito Impresso (PCI) que possuem em sua composição metais nobres e base, sendo o cobre presente em teores de 10-20%. Além disso, também estão presentes metais tóxicos, tais como chumbo, cádmio e mercúrio, os quais podem acarretar grandes malefícios a natureza e a saúde humana. Portanto, a reciclagem de PCI é uma iniciativa importante, não só devido a questões ambientais, mas também a aspectos econômicos. Diante do exposto, o presente trabalho visou otimizar as variáveis (i) densidade de polpa, (ii) concentração de cloreto férrico hexahidratado, (iii) concentração de ácido clorídrico e (iv) tempo durante a lixiviação do cobre contido em PCI de computadores utilizando planejamentos experimentais multivariados. Os ensaios de lixiviação foram realizados em bateladas em um shaker, sob agitação de 150min-1 e temperatura de 25±1°C. As condições ótimas para a lixiviação de cobre foram densidade de polpa de 120g.L-1, concentrações de cloreto férrico hexahidratado e de ácido clorídrico de 1mol.L-1 e tempo de 40 minutos. Para a condição otimizada, a percentagem de lixiviação de cobre foi de 96,22±1,20%.
Palavras-chave
Abstract
The volume of Waste Electrical and Electronic Equipment (WEEE) produced worldwide in 2018 was 50 million tons. Around 2% of this waste is Printed Circuit Boards (PCB), which contain noble and base metals, with copper being the most abundant element (10-20%). Additionally, toxic metals as lead, cadmium and mercury are present, which can cause harmful effects to the environment and human health. Therefore, PCB recycling is an important initiative, not only due to environmental issues but also considering the economic aspects. This research aimed to optimize the variables (i) pulp density, (ii) concentration of ferric chloride hexahydrate, (iii) concentration of hydrochloric acid and (iv) time that influence the copper leaching process contained in PCB of computers through a multivariate experimental design. The leaching assays were carried out in batches, in a shaker, under stirring of 150min-1 and temperature of 25±1°C. The optimum conditions for copper leaching were pulp density of 120g.L-1, concentration of ferric chloride hexahydrate and hydrochloric acid of 1mol.L-1, and time of 40 minutes. For the optimized condition, the percentage of copper leaching was 96.22±1.20%.
Keywords
References
1 Chu Y, Chen M, Chen S, Wang B, Fu K, Chen H. Micro-copper powders recovered from waste printed circuit boards by electrolysis. Hydrometallurgy. 2015;156:152-157. http://dx.doi.org/10.1016/j.hydromet.2015.06.006.
2 Beatriz M. Obsolescência programada e teoria do decrescimento versus direito ao desenvolvimento e ao consumo (Sustentáveis). Veredas do Direito. 2012;9(17):181-196.
3 Henrique S Jr, Moura F, Correa R, Afonso J, Vianna C, Mantovano J. Processamento de placas de circuito impresso de equipamentos eletroeletrônicos de pequeno porte. Química Nova. 2013;36(4):570-576. http://dx.doi.org/10.1590/S0100-40422013000400015.
4 Estrada-Ruiz R, Flores-Campos R, Gámez-Altamirano H, Velarde-Sánchez E. Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology. Journal of Hazardous Materials. 2016;311:91-99. http://dx.doi.org/10.1016/j.jhazmat.2016.02.061.
5 Neto I, Sousa C, Brito M, Futuro A, Soares H. A simple and nearly-closed cycle process for recycling copper with high purity from end life printed circuit boards. Separation and Purification Technology. 2016;164:19-27. http://dx.doi.org/10.1016/j.seppur.2016.03.007.
6 Sarvar M, Salarirad M, Shabani M. Characterization and mechanical separation of metals from computer Printed Circuit Boards (PCBs) based on mineral processing methods. Waste Management. 2015;45:246-257. http://dx.doi.org/10.1016/j.wasman.2015.06.020.
7 Betts K. Reducing the global impact of e-waste. Environmental Science & Technology. 2008;42(5):1393. http://dx.doi.org/10.1021/es087087p.
8 Yamane L, Moraes V, Espinosa D, Tenório J. 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.
9 Tesfaye F, Lindberg D, Hamuyuni J, Taskinen P, Hupa L. Improving urban mining practices for optimal recovery of resources from e-waste. Minerals Engineering. 2017;111:209-221. http://dx.doi.org/10.1016/j.mineng.2017.06.018.
10 Kumar A, Holuszko M, Espinosa D. E-waste: An overview on generation, collection, legislation and recycling practices. Resources, Conservation and Recycling. 2017;122:32-42. http://dx.doi.org/10.1016/j.resconrec.2017.01.018.
11 Yamane L. Recuperação de metais de placas de circuito impresso de computadores obsoletos através de processo biohidrometalúrgico [tese]. São Paulo: Escola Politécnica, Universidade de São Paulo; 2012. http://dx.doi.org/10.11606/T.3.2012.tde-07062013-154359.
12 Chen M, Huang J, Ogunseitan O, Zhu N, Wang Y. Comparative study on copper leaching from waste printed circuit boards by typical ionic liquid acids. Waste Management. 2015;41:142-147. http://dx.doi.org/10.1016/j.wasman.2015.03.037.
13 Birloaga I, De Michelis I, Ferella F, Buzatu M, Vegliò F. Study on the influence of various factors in the hydrometallurgical processing of waste printed circuit boards for copper and gold recovery. Waste Management. 2013;33(4):935-941. http://dx.doi.org/10.1016/j.wasman.2013.01.003.
14 Yang H, Liu J, Yang J. Leaching copper from shredded particles of waste printed circuit boards. Journal of Hazardous Materials. 2011;187(1–3):393-400. http://dx.doi.org/10.1016/j.jhazmat.2011.01.051.
15 Souza C. Copper extraction from electronic scraps by oxidative acid leaching process printed circuit board coming from several types of equipments. In: Centre for Mineral Technology. Proceedings of the 6th International Seminar on Copper Hydrometallurgy; 2011 July 6-8; Viña del Mar, Chile. Brazil: CETEM; 2011. p. 1-8.
16 Oh C, Lee S, Yang H, Ha T, Kim M. Selective leaching of valuable metals from waste printed circuit boards. Journal of the Air & Waste Management Association. 2003;53(7):897-902. http://dx.doi.org/10.1080/10473289.2003.10466230.
17 Wang X, Gaustad G. Prioritizing material recovery for end-of-life printed circuit boards. Waste Management. 2016;31:917-924. https://doi.org/10.1016/j.wasman.2012.05.005.
18 Torres R, Lapidus G. Copper leaching from electronic waste for the improvement of gold recycling. Waste Management. 2016;57:131-139. http://dx.doi.org/10.1016/j.wasman.2016.03.010.
19 Lee J, Kumar M, Kim M-S, Jeong J, Yoo K. Leaching of metals from waste printed circuit boards (WPCBs) using sulfuric and nitric acids. Environmental Engineering and Management Journal. 2014;13(10):2601-2607. http://dx.doi.org/10.30638/eemj.2014.290.
20 Caldas M. Síntese de nanopartículas de prata a partir de reciclagem de clacas de circuito impresso [tese]. São Paulo: Escola Politécnica, Universidade de São Paulo; 2017.
21 Deveci H, Ball T. A visual insight into the oxidation of sulfide minerals during bioleaching and chemical leaching of a complex ore. Mineral Processing and Extractive Metallurgy Review. 2010;31(3):176-190. http://dx.doi.org/10.1080/08827508.2010.482859.
22 Al-Harahsheh M, Kingman S, Al-Harahsheh A. Ferric chloride leaching of chalcopyrite: synergetic effect of CuCl2 . Hydrometallurgy. 2008;91(1-4):89-97. http://dx.doi.org/10.1016/j.hydromet.2007.11.011.
23 Godočíková E, Baláž P, Boldižárová E. Structural and temperature sensitivity of the chloride leaching of copper, lead and zinc from a mechanically activated complex sulphide. Hydrometallurgy. 2002;65(1):83-93. http://dx.doi.org/10.1016/S0304-386X(02)00094-4.
24 Ho K, Mohapatra D, Reddy B. A study on the acidified ferric chloride leaching of a complex (Cu–Ni–Co–Fe) matte. Hydrometallurgy. 2006;51:332-337.
25 Teófilo F. Planejamentos experimentais para a otimização da resposta voltamétrica na determinação do herbicida glifosato em solo, água e vegetais [tese]. Viçosa: Programa de Pós-graduação em Agroquímica, Universidade Federal de Viçosa; 2003.
26 Lazić R. Design of experiments in chemical engineering. Catalonia: Wiley-VCH; 2004. . http://dx.doi.org/10.1002/3527604162.
27 Teófilo F, Ferreira C. Quimiometria II: planilhas eletrônicas para cálculos de planejamentos experimentais, um tutorial. Química Nova. 2006;29(2):338-350. http://dx.doi.org/10.1590/S0100-40422006000200026.
28 Cunico MWM, Cunico MM, Miguel OG, Zawadzki SF, Peralta-Zamora P, Volpato N. Planejamento fatorial: Uma ferramenta estatística valiosa para a definição de parâmetros experimentais empregados na pesquisa científica. Visão Acadêmica. 2008;9(1):23-32. http://dx.doi.org/10.5380/acd.v9i1.14635.
29 Bezerra A, Santelli E, Oliveira P, Villar S, Escaleira A. Response surface methodology (RSM) as a tool for optimization in analytical chemistry. Talanta. 2008;76(5):965-977. http://dx.doi.org/10.1016/j.talanta.2008.05.019.
30 Maia R. Método do vetor gradiente multivariado [dissertação]. Itajubá: Programa de Pós-graduação em Engenharia de Produção, Universidade Federal de Itajubá; 2013.
31 Pereira M, Gomes R, Rodrigues M, Leão V. Mechanical processing and characterization of printed circuit boards. In: Proceedings of European Metallurgical Conference; 2019 June 23-26; Düsseldorf, Germany. Clausthal-Zellerfeld: GDMB; 2019. p. 1019-1036.
32 Skoog D, West D, Holler F, Crouch R. Fundamentos de química analítica. 8. ed. São Paulo: Thomson; 2006.
33 Havlik T, Orac D, Petranikova M, Miskufova A, Kukurugya F, Takacova Z. Leaching of copper and tin from used printed circuit boards after thermal treatment. Journal of Hazardous Materials. 2010;183(1-3):866-873. http://dx.doi.org/10.1016/j.jhazmat.2010.07.107.
Submitted date:
01/30/2019
Accepted date:
03/18/2020
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email