ARBOK-Tantalum: Recovering Tantalum from E-waste Leach Solutions by Vacuum Separation

Tantalum is a critical metal that the importing countries do not mine and cannot easily replace. The world mines about 2,500 t a year, about two thirds of it in Congo and Rwanda, and about 50% of it goes into one component, the tantalum capacitor. Production scrap returns to circulation, but from end-of-life products discarded by consumers less than 1% of the metal is recovered. Electronics recyclers shred, smelt and leach printed circuit boards for gold, copper and palladium; tantalum earns them nothing, dissolves only in the most aggressive mixtures, and is lost to slag. We describe ARBOK-Tantalum, an application of the ARBOK vacuum platform to the board-leaching solutions that recyclers already hold. Water is evaporated under deep vacuum at ambient temperature and returned clean; everything dissolved stays in the concentrate, tantalum among it. In the same line gold pays for the module and tantalum is added on top. More than 1,000 t of tantalum a year, worth more than USD 200 mln as oxide, sits in discarded equipment and can be recovered without a pit, a checkpoint or an origin audit.