TY - JOUR
T1 - Leaching reaction of manganese dioxide from tantalum capacitor scrap. A study on the recycling of high quality rare metal secondary resource
AU - Wei, Yuezhou
AU - Sato, Nobuaki
AU - Takenaka, Toshihide
AU - Nanjo, Michio
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1989
Y1 - 1989
N2 - A process is proposed for the recycling of Ta capacitor scrap containing 4-7% MnO2 as solid electrolyte. This paper describes the removal leaching of MnO2 with various agents and disscusses the dissolution reaction of MnO2 in FeSO4-H2SO4 aqueous solution from thermodynamic and kinetic aspects. In leaching of block Ta anode scrap, H2O2 and Na2SO3 solution were the most effective leaching agents, with more than 90% of Mn extraction at room temperature after 24 hours. When the sample was ground to -200 mesh, MnO2 was almost completely removed in a short time by use of H2O2 solution. FeSO4 solution also showed a satisfactory result. The overall reaction of the primary per was controlled by mass transfer of Fe2+ ions through the boundary layer between the solution and the surface of MnO2 inside the capacitor. Dissolution of Fe(OH)3 and other reaction products was the rate determining step in the secondary per Hermetic seal type Ta capacitor scrap was upgraded by applying the Fe3+/Fe2+ oxidative-reductive leaching method.
AB - A process is proposed for the recycling of Ta capacitor scrap containing 4-7% MnO2 as solid electrolyte. This paper describes the removal leaching of MnO2 with various agents and disscusses the dissolution reaction of MnO2 in FeSO4-H2SO4 aqueous solution from thermodynamic and kinetic aspects. In leaching of block Ta anode scrap, H2O2 and Na2SO3 solution were the most effective leaching agents, with more than 90% of Mn extraction at room temperature after 24 hours. When the sample was ground to -200 mesh, MnO2 was almost completely removed in a short time by use of H2O2 solution. FeSO4 solution also showed a satisfactory result. The overall reaction of the primary per was controlled by mass transfer of Fe2+ ions through the boundary layer between the solution and the surface of MnO2 inside the capacitor. Dissolution of Fe(OH)3 and other reaction products was the rate determining step in the secondary per Hermetic seal type Ta capacitor scrap was upgraded by applying the Fe3+/Fe2+ oxidative-reductive leaching method.
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U2 - 10.2473/shigentosozai.105.181
DO - 10.2473/shigentosozai.105.181
M3 - Article
AN - SCOPUS:0024612734
VL - 105
SP - 181
EP - 187
JO - Shigen to sozai
JF - Shigen to sozai
SN - 0916-1740
IS - 2
ER -