title: High temperature investigations on optimising the recovery of copper from waste printed circuit boards.
abstract: High temperature pyrolysis investigations were carried out on waste printed circuit boards (PCBs) in the temperature range 800-1000°C under inert conditions, with an aim to determine optimal operating conditions for the recovery of copper. Pyrolysis residues were characterized using ICP-OES analysis, SEM/EDS and XRD investigations. Copper foils were successfully recovered after pyrolysis at 800°C for 10-20 min; the levels of Pb and Sn present were found to be quite low and these were generally present near the foil edges. The relative proportions of Pb and Sn became progressively higher at longer heating times due to enhanced diffusion of these molten metals in solid copper. While a similar behaviour was observed at 900°C, the pyrolysis at 1000°C resulted in copper forming Cu-Sn-Pb alloys; copper foils could no longer be recovered. Optimal conditions were identified for the direct recovery of copper from waste PCBs with minimal processing. This approach is expected to make significant contributions towards enhancing material recovery, process efficiency and the environmental sustainability of recycling e-waste. Pyrolysis at lower temperatures, short heating times, coupled with reductions in process steps are expected to significantly reduce energy consumption and pollution associated with the handling and processing of waste PCBs.
authors.affiliation: Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Cayumil
authors.affiliation: Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Ikram-Ul-Haq
authors.affiliation: Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia. Electronic address: ritakhanna@unsw.edu.au.
authors.forename: R
authors.initials: R
authors.lastname: Khanna
authors.affiliation: Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Saini
authors.affiliation: CSIR - Institute of Minerals and Material Technology, Advanced Materials Technology Department, Bhubaneshwar, Orissa 751013, India.
authors.forename: P S
authors.initials: PS
authors.lastname: Mukherjee
authors.affiliation: CSIR - Institute of Minerals and Material Technology, Advanced Materials Technology Department, Bhubaneshwar, Orissa 751013, India.
authors.forename: B K
authors.initials: BK
authors.lastname: Mishra
authors.affiliation: Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: V
authors.initials: V
authors.lastname: Sahajwalla
mesh_terms: D000497:Alloys; D003201:Computers; D003300:Copper; D059029:Electronic Waste; D059027:Recycling; D013696:Temperature
chemical_list: D000497:Alloys; D003300:Copper
keywords: Copper recovery; E-waste; Energy efficiency; PCBs; Pollution; Pyrolysis