high tech recycling inter-university research center ... · wpcbs characterization for recycling...
TRANSCRIPT
![Page 1: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/1.jpg)
Hydrometallurgical processing of
waste printed circuit boards for Cu, Au
and Ag recovery
Ionela Birloaga - University of L’Aquila, Italy
Ida De Michelis - EcoRecycling
Bernd Kopacek - Austrian Society for Systems
Engineering and Automation, Austria
Francesco Vegliò - University of L’Aquila, Italy
HIGH TECH RECYCLING
INTER-UNIVERSITY RESEARCH CENTER
Outline
� Introduction
� Waste Printed Circuit Boards (WPCBs)
� Hydrometallurgical process
�Block diagram
�Cu recovery
�Au and Ag recovery
�Waste water treatment
� Next steps
![Page 2: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/2.jpg)
Introduction
� The WEEE Directive 2002/96/EC was revised by the European
Commission and, as result, the new Directive 2012/19/EU was
introduced. By this the following collection targets have been
introduced:
�45% of the sold electronic equipments (starting with 2016);
�65% of the sold electronic equipments or 85% of e-wastes
generated(starting with 2019).
� Most of all electronic components present in their structure
printed circuit boards (PCB)
Current recycling technologies
Mechanical - PhysicalIncomplete separation of
elements - pretreatment
Pyrometallurgy Hydrometallurgy Biometallurgy
Ionometallurgy
High capital cost; loss of
byproducts in slags
and residues
Presents more flexibility
during the upscaling and
control processes
In the incipient phase
In early stage and
relatively high cost of
reagents
![Page 3: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/3.jpg)
WPCBs
Characterization for recycling
oMore than 10% of worldwide reserve of Au is used in the
manufacturing of electronic devices.
oDepending on their gold content, the WPCBs are divided into
three categories, namely:
• high grade (>200 mg/kg)
• medium grade (100<200 mg/kg)
• low grade (<100 mg/kg)
Economic drivers in WPCBs treatment (Wang and
Gaustad, Waste Management, 32 (2012))
WPCBs
Structure and their electronic components
analysis1 Al electrolytic capacitors
2 Heat sink- Al
3 Black panel - Steel, plastic and pins (Cu, Au, Al)
4 Inductors - Cu and ferrite
5 Quartz resonators
6 Battery
7 Multi-layer ceramic capacitors (MLCC)
(Ag- 9.5 g/kg; Pd - 1.02g/kg; Nb – 13.29%; Ta – 0.49%)
8 Tantalum ceramic capacitors (Ag – 1 %; Ta –
20%)
9 IC chips (Ag – 1 g/kg; Au – 890 mg/kg; Pd – 15 mg/kg)
![Page 4: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/4.jpg)
Hydrometallurgical process
Block diagram
Motherboard with
mounted components
Removal of a part of
Al base componentsMilling to a particle
size of <1mm
Cu Zn Al Fe Sn Pb Ni Ag Au Pd
% (wt./wt.) mg/kg
20.84 2.79 4.57 2.39 5.11 2.78 0.22 689 306 42
Chemical analysis of WPCBs sample
Preparation and characterization
of the WPCBs sample
![Page 5: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/5.jpg)
Recovery of Cu
Oxidative leaching process
Cu + H2SO4 + H2O2 = CuSO4 + 2H2O
Cu recovery >98% are observed at lab scale
Cementation with Zn metal powder
Au and Ag recovery
Thioureation process
2Au + Fe2(SO4)3 + 4SC (NH2)2 = [Au (SC (NH2)2)2]2SO4 + 2FeSO4
2Ag + Fe2(SO4)3 + 6SC (NH2)2 + SO2-4 = [Ag (SC (NH2)2)3]2SO4 + 2FeSO4
Neutralization with sodium hydroxide and cementation with
Zn metal powder
[Au(SC(NH2)2)2]2SO4 + Zn → 2Au + 4CS(NH2)2 + ZnSO4
[Ag(SC(NH2)2)3]2SO4 + Zn → 2Ag + 6CS(NH2)2 + ZnSO4
Gold and silver complete precipitation
with NaOH at pH 2 and cementation with Zn
![Page 6: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/6.jpg)
Waste water treatment
ParameterUnit of
measure
Initial
conditions
After Fenton
treatment
Final treatment
with Ca(OH)2
Leg. It.
pH 2.5 1.9 10 5.5-9.5
TDS g/L 51 28.82
SST g/L 2.6
COD mg/L 11600 2057 520 500
Abatement
of COD% 74 9494
SO4-2 g/L 54 45.72 18.62
Abatement
of SO4-2
% 40.7240.72
Fenton process
Fe2+ + H2O2 → Fe3+ + OH• + OH
OH• + Fe2+ → OH− + Fe3+
Next steps
� Recovery of other valuable elements (on progress) for a
better sustainability of the process
� Improve of purity level of the outputs
� Mobile plant tests
![Page 7: HIGH TECH RECYCLING INTER-UNIVERSITY RESEARCH CENTER ... · WPCBs Characterization for recycling oMore than 10% of worldwide reserve of Au is used in the manufacturing of electronic](https://reader034.vdocument.in/reader034/viewer/2022042118/5e9667624b2c5a35e14e997b/html5/thumbnails/7.jpg)