A Review on the Recovery of Tantalum Oxide from Tantalum Capacitors of Printed Circuit Boards

Tantalum oxide (Ta₂O₅), used in solid-state capacitors of printed circuit boards (PCBs), is a critical metal essential for miniaturized electronics. Due to limited global reserves and geopolitical risks, recycling tantalum from electronic waste is gaining importance. This review explores current and emerging techniques for recovering tantalum oxide from scrap tantalum capacitors.Pyrometallurgical methods like plasma and chlorination offer high-purity outputs but are energy-intensive. Hydrometallurgical approaches, especially those using hydrofluoric acid, provide excellent selectivity but pose environmental hazards. To address these issues, integrated pyro-hydrometallurgical flowsheets are gaining attention. Processes such as pyrolysis followed by acid leaching or chlorination have demonstrated high efficiency and reduced environmental impact. The review also highlights innovative methods like microwave-assisted reduction and zeolite-based purification as future pathways. Overall, the paper emphasizes that a combination of advanced processing technologies and improved e-waste sorting systems is key to achieving sustainable tantalum recovery from discarded electronics.