Journal
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
Volume 5, Issue 5, Pages 4421-4428Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acssuschemeng.7b00496
Keywords
E-waste; Waste tantalum capacitors; Tantalum recovery; Supercritical water; Environmental conservation
Categories
Funding
- National Natural Science Foundation of China [51534005]
Ask authors/readers for more resources
Recycling e-waste has been a significant topic for environmental protection and also for resource recovery. Waste tantalum capacitors (WTCs), widely existing in discarded small appliances, are rich in high quality tantalum (Ta) resources. However, recovering Ta from WTCs is difficult due to the tightly covered mold resin. This study proposes an efficient and environmentally friendly process using supercritical water (SCW) to decompose the organics and recover Ta from WTCs. Two methods of SCW were studied: SCW depolymerization (SCWD) and SCW oxidation (SCWO). The results indicated that the mold resin (packing) of WTCs were effectively decomposed by SCW treatments. The organic decomposition efficiency in SCWD was lower than that in SCWO. The optimal parameters for SCWD and SCWO were, respectively, considered to be 425 degrees C, 25 MPa, and 120 min and 400 degrees C, 25 MPa, and 90 min, adding a 10% volume ratio of H2O2. After SCWO treatment, Ta electrodes were directly recovered, and the purity of Ta could reach 93.18%. For the sample treated by SCWD, Ta powder could be further recovered by mechanical separation. This study presents an efficient and environmentally friendly process to recover Ta from e-waste, which is significant for resource regeneration and environmental conservation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available