An integrated and environmental-friendly technology for recovering valuable materials from waste tantalum capacitors

Waste printed circuit boards (WPCBs) are valuable urban ore for recycling. Many efforts have been done to recover resources from basal boards of WPCB. In addition to basal boards, WPCBs contain many electronic components. However, the recycling technology for electronic components has been poorly developed. This study proposed an integrated and environment-friendly technology for recycling waste tantalum capacitors (WTCs) of WPCBs. Firstly, the WTCs were treated by argon pyrolysis to decompose mold resin. The pyrolysis temperature of 550 °C and holding time for 30 min were considered as the optimal parameters. Then, the pyrolysis residues were performed by crush and magnetic separation to recover nickel-iron terminals. Finally, chloride metallurgy (CM) was used to recover rare metal tantalum (Ta). The Ta recovery rate could reach 92.87 ± 0.36%. The optimal parameters were determined as temperature of 493 °C, adding FeCl 2 ·4H 2 O of 53 wt% and holding time for 150 min based on the response surface methodology (RSM). This study exploits an efficient approach for recycling WTCs and provides a reference for future industrial application.