Copper and metals concentration from printedcircuit boards using a zig-zag classifier

Author(s): Ribeiro, Pedro Paulo Medeiros; Santos, Iranildes Daniel dos; Dutra, Achilles Junqueira Bourdot
Summary: The consumption of electronic products has grown considerably in the last decades. Theseproducts become obsolete in a short period of time, generating electronic waste, whichpresents loads of materials harmful to health and metals of great value to industries. In thiswork, an innovative metal concentration technique for PCBs was applied aiming at the valu-able metals recovery from ground printed circuit boards (PCBs) of computers that would bediscarded. The PCBs were comminuted, classified by sieving and the metallic materials wereprocessed in a zig-zag classifier type. The Schytil’s phase diagram was developed to estimatethe air flow rate to be used in the classifier. The product of each step was characterized. Thecopper content rose from 13.8% (w/w) to 48.8% (w/w) after the passage of the PCBs pow-der through the classifier. Its recovery and Newton’s efficiency were above 89.4% and 0.91,respectively. The total content of metals was increased from 39.5% (w/w) to 89% (w/w) witha recovery of more than 82% and Newton’s efficiency of 0.67 for the particle size in the rangefrom 0.2 to 0.1 mm. The gold content has increased from 200 ppm to more than 8000 ppmafter segregation by a simple manual concentration. Results shown that the use of zig-zagclassifier to separate and concentrate metals was fairly effective, do not generate liquid andgaseous effluents and eliminates a number of pyrometallurgical or hydrometallurgical stepsfor metals obtaining.
Journal: Journal of Materials Research and Technology
Year: 2018
Volume: v. 8
Pages: p. 513-520
DOI: https://doi.org/10.1016/j.jmrt.2018.05.003
Year of publication: 2019
Available at: https://www.sciencedirect.com/science/article/pii/S2238785417304829?via%3Dihub
Publisher and ISSN: Elsevier