Issue 60, 2017, Issue in Progress

Characterization of waste printed circuit boards recycled using a dissolution approach and ultrasonic treatment at low temperatures

Abstract

Recently, the separation of waste printed circuit boards (WPCBs) using organic solvents has become more prevalent because it is an environmentally friendly and efficient technique. However, the relatively high temperatures (∼135 °C) used during the separation process lead to higher energy consumption, faster solvent degradation, and possibly higher emissions of toxic fumes. This work aims to develop a new approach to separate all layers of WPCBs at lower temperatures to avoid the above-mentioned drawbacks. Di-methyl formamide (DMF) was used in the present technique as an organic solvent, while ultrasonic treatment was applied in order to accelerate the breakage of the internal van der Waals bonds of brominated epoxy resin (BER), thus decreasing the separation time. The experiments were conducted on five WPCB samples with the same surface area of 100 mm2, cut from five different WPCB models. The experiments were carried out at 25 °C (used as a reference), 50 °C, and 75 °C to study the effect of heating rate on the separation time and on the concentration of the BER dissolved in DMF. Ultraviolet-visible spectroscopy, metallographic microscope, and SEM-EDS were used to examine the recovered BER and fiberglass structure as well as the main metal compositions of each sample, respectively. The results showed that separation time and concentration of BER strongly depended on the WPCB models. In addition, the dissolution process at 50 °C resulted in the concentration of BER close to 25 °C for most of the models, while the concentration was lowest at 75 °C. At the same time, the trend in separation time was exactly opposite, with 75 °C resulting in the fastest separation time and 25 °C in the slowest. This facile approach appears promising for its potential applications in WPCB recycling and could be applied on an industrial scale.

Graphical abstract: Characterization of waste printed circuit boards recycled using a dissolution approach and ultrasonic treatment at low temperatures

Article information

Article type
Paper
Submitted
24 Jun 2017
Accepted
19 Jul 2017
First published
31 Jul 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 37729-37738

Characterization of waste printed circuit boards recycled using a dissolution approach and ultrasonic treatment at low temperatures

M. Tatariants, S. Yousef, R. Sidaraviciute, G. Denafas and R. Bendikiene, RSC Adv., 2017, 7, 37729 DOI: 10.1039/C7RA07034A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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