Organic chemistry

Organic acid

Citric acid

Tantalum

Dissolution

Nuclear chemistry

Inorganic chemistry

Chemistry

Metallurgy

Scrap

Materials science

Sulfuric acid

Oxide

Oxalic acid

Pyrolysis

Manganese

Acta Innovations

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.

Dissolution of manganese (IV) oxide from tantalum capacitor scrap by organic acids