| Abstract Scope |
Waste tantalum capacitors are potential secondary source of valuable metals such as manganese, nickel and
tantalum. In this work, a hydrometallurgical approach was investigated to selectively dissolve Mn and Ni into
the leach liquor. The capacitors were pretreated, and various leaching parameters, like the effect of leachant,
solid-to-liquid ratio, acid concentration, time, and temperature, were studied. The process was optimised using
dilute nitric acid at an elevated temperature, a solid-to-liquid ratio of 75g/L, and a leaching time of 3 hours.
Under these conditions, 99.99% dissolution of Mn and Ni was obtained, whereas tantalum remained
undissolved and became concentrated in the residue. The leaching was carried out in a closed system with a
condenser to control acid loss and reduce NO x emissions. This route provides a simple, selective method for
recovering Mn and Ni along with producing a Ta-enriched residue from waste capacitors. |