Selective thermal transformation of e-waste to novel metallic alloys

This thesis introduces a new innovative solution for transforming Printed Circuit Boards (PCBs) into value-added materials. As the main approach to achieve this gaol, this thesis investigates, verifies and determines the optimal parameters for the selective thermal transformation of problematic PCBs which is one of the main components of electronic waste (e-waste) to produce value-added metallic alloys. This research demonstrated a novel pathway for the cost-effective recovery of resources from one of the world’s fastest growing and most challenging waste streams. Using outdated PCBs from different source such as computer, printer and DVD drivers, we investigated transformations across a range of temperatures and time frames for 5 different PCBs and propose an innovative solution to use this problematic waste as a source for raw materials. Investigation has shown that selective thermal transformation of e-waste is an effective way to produce value-added metallic alloys from these sources of wastes. In this thesis for the first time “Thermal Micronizing” mechanism has been introduced. In this mechanism, the plastics in the waste generated a reducing environment which acted as a “thermal micronizing” media and at the same time protecting the nanoparticles from oxidation, while solid carbon minimized agglomeration. Also, two step heat treatment approach has been investigated to remove the toxic and low melting point elements first and then go to high temperature and produce Cu-based alloys without toxic elements. Results indicate a two-step heat treatment process, using a low temperature step followed by a high temperature step, can be used to produce and separate off, first, a lead (Pb) based alloy and, subsequently, a Cu-Sn based alloy. These results demonstrate old computer PCBs, large volumes of which are already within global waste stockpiles, can be considered a potential source of value-added metal alloys, opening up a new opportunity for utilizing e-waste to produce metal alloys in local micro-factories.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2018

Author dc:creator

• Shokri, Ali

• Nano particles
• E-waste
• Thermal micronizing
• Metal recovery
• Selective transformation

Statement dc:rights

• open access
• CC BY-NC-ND 3.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by-nc-nd/3.0/au/

Language dc:language

EN

Identifier

https://doi.org/10.26190/unsworks/21386

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/63307