title: Recovery of copper from printed circuit boards scraps by mechanical processing and electrometallurgy.
abstract: The constant growth in generation of solid wastes stimulates studies of recycling processes. The electronic scrap is part of this universe of obsolete and/or defective materials that need to be disposed of more appropriately, or then recycled. In this work, printed circuit boards, that are part of electronic scrap and are found in almost all electro-electronic equipments, were studied. Printed circuit boards were collected in obsolete or defective personal computers that are the largest source of this kind of waste. Printed circuit boards are composed of different materials such as polymers, ceramics and metals, which makes the process more difficult. However, the presence of metals, such as copper and precious metals encourage recycling studies. Also the presence of heavy metals, as Pb and Cd turns this scrap into dangerous residues. This demonstrates the need to search for solutions of this kind of residue, in order to have it disposed in a proper way, without harming the environment. At the first stage of this work, mechanical processing was used, as comminution followed by size, magnetic and electrostatic separation. By this process it was possible to obtain a concentrated fraction in metals (mainly Cu, Pb and Sn) and another fraction containing polymers and ceramics. The copper content reached more than 50% in mass in most of the conductive fractions and significant content of Pb and Sn. At the second stage, the fraction concentrated in metals was dissolved with acids and treated in an electrochemical process in order to recover the metals separately, especially copper. The results demonstrate the technical viability of recovering copper using mechanical processing followed by an electrometallurgical technique. The copper content in solution decayed quickly in all the experiments and the copper obtained by electrowinning is above 98% in most of the tests.
authors.affiliation: LACOR, PPGEM, Universidade Federal do Rio Grande do Sul, Campus do Vale, Setor 4, Prédio 74, Av. Bento Gonçalves 9500, CEP 91501-970 Porto Alegre, RS, Brazil. hugomv@pop.com.br
authors.forename: Hugo Marcelo
authors.initials: HM
authors.lastname: Veit
authors.forename: Andréa Moura
authors.initials: AM
authors.lastname: Bernardes
authors.forename: Jane Zoppas
authors.initials: JZ
authors.lastname: Ferreira
authors.forename: Jorge Alberto Soares
authors.initials: JA
authors.lastname: Tenório
authors.forename: Célia
authors.initials: C
authors.lastname: de Fraga Malfatti
mesh_terms: D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D008280:Magnetics; D008669:Metallurgy; D010316:Particle Size; D055672:Static Electricity
chemical_list: D003300:Copper