DISSOLUTION OF MANGANESE (IV) OXIDE FROM TANTALUM CAPACITOR SCRAP BY ORGANIC ACIDS

Abstract

The dissolution of MnO2 from tantalum capacitor scrap using organic acids in various process conditions was
studied. The initial materials were of two types: LTC (leaded tantalum capacitors) and SMDTC (surface-mounted
device tantalum capacitors). The research materials were prepared by pyrolysis, grinding and sieving and the
preparation processes were characterized. Dissolution of MnO2 was carried out with the use of sulfuric acid
solutions with the addition of acetic, ascorbic, citric and oxalic organic acids. Results show that the addition of
organic acids significantly improves dissolution yields (72-94 vs 90-99 % for H2SO4 and acid mixtures,
respectively). In practice, a concentration of organic acid above 1 M results in the complete removal of MnO2.