The role of Sub-Saharan Africa Countries’ households waste charges on sustainable cities development
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Waste Resources
Abstract
The increasing use of rare earths elements (REEs) in a number of recent technological innovations led to a rapid increase (>50% in the last decade) in their applications. Europe is one of the most important regions of consumption of these substances. In this context, Europe in its 'Raw materials' strategy puts the recycling at the center of its concerns to provide a part of securing its supplies in REEs. Recycling of these substances, on an industrial scale, remains somewhat developed while it presents numerous advantages over the exploitation of primary resources. This paper will present some results obtained from characterization study of permanent magnets (PMs) present in WEEEs. Three components containing PMs are identified: hard disk drives, small electric motors and speakers. The representative sample of these components has been dismantled manually to recover the PMs contained and to quantify their amount. The results show that the weight percentage of the PMs varies from 4 to 6% in the speakers, 2.5 to 2.8% in the hard disks, and between 0.8 and 2% in some electric motors. The results of the thermal treatment of the Nd-Fe-B PMs of the investigated samples show that the majority of these PMs lose their magnetic property upon reaching Curie temperature (300-400°C) in 15-20 min. Scanning Electronic Microscopy reveals the morphological aspects of the PM which consist in crystals shaped tetrahedral phase Nd2Fe14B sintered in the presence of the interphase rich in Nd, Dy and Pr. The PM are layer coated with 20 µm thick, consisting of Ni, Zn or metals alloys.
Description
International Journal of Waste Resources, 2017; 7 (1)
Keywords
Wastes, Households, Equipment, Recycling