Chemical and phisical characterization of memory boards from obsolete computers through optical emission spectrometry and scanning electron microscopy

Abstract

The combination between the high volume of waste electrical and electronic equipment (WEEE) and the increased planned obsolescence makes it necessary thinking about alternative ways to dispose these wastes, such as recycling followed by metal recovery, without affecting the environment and human health. In order to do so, it is essential understanding the nature of the waste-constituent materials. Printed Circuit Boards (PCB) are important representatives of WEEE, since they are found in most electronic equipment such as computers. PCB heterogeneous composition comprises high metal contents - some of them are precious metals, which represent almost the entire intrinsic value of the board and that justifies applying recycling processes to recover them. The aim of the present study is to investigate the characterization of memory boards from obsolete computers for the subsequent recovery of its precious metals. It was possible to conclude that the memory board mass comprised 18.9% metals, 48.4% ceramics and 32.7% polymers. Cu was the most expressive metal, since it accounted for 13.83% of the board mass. Precious metals such as Ag and Au represented only 0.053% and 0.069% of the board mass, respectively; however, their high market value justifies their recovery.