TITLE:
Cell-Phone Recycling by Solvolysis for Recovery of Metals
AUTHORS:
Lorena Eugenia Sánchez Cadena, Zeferino Gamiño Arroyo, Mario Alberto González Lara, Q. Demetrio Quiroz
KEYWORDS:
Cell-Phones, Solvolysis, Recycling
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.1,
January
20,
2015
ABSTRACT:
Mobile phones represent a significant and
growing problem with respect to electrical waste and electronic equipment
(WEEE). Nevertheless, they are perhaps one of the most valuable electronic
products, since they are an important resource for the recovery of metals in
terms of mass and volume. In this research a chemical recycling of mobile
phones by solvolysis was investigated. The processing was performed by
comminution in a hammer mill followed by screening to obtain mesh-4 sized
flakes. Flakes were subjected to solvolysis. Different reaction conditions were
tested. A reaction time between 2 - 7 hours and a temperature between 150°C - 300°C
were the optimum conditions to dissolve the polymer contained in mobile phones.
Metals were separated by filtration. Chemical analyses (ATR FT-IR, UV) were
carried out on the solvent and the mobile phone flakes before and after
solvolysis. A SEM study was carried out, before and after solvolysis, but only
to the mobile phone flakes. Thermal transitions of mobile phone flakes were
determined by DSC. Chemical results showed that some aromatic species migrate
from mobile phones flakes to the solvent, due to the solvolysis reaction.
Thermal analysis showed that the Tg, (glass transition temperature) of mobile
phone flakes after solvolysis was different to Tg of the polymer before
solvolysis, this is due to chemical changes in the molecule. A comparative SEM
study revealed that, after solvolysis, the polymer contained in mobile phone
flakes is more elastomeric. After solvolysis, solvent was recovered by means of
a rotatory evaporator, so that it can be used again. The results obtained in
this research showed that solvolysis is an alternative for metal recovery from
mobile phones.