Recovery of tantalum parts from used capacitor using steam gasification with mixted molten carbonate

Takaaki Wajima, Shigeyuki Katano, Shingo Nakamura, Zar Zar Hlaing, Maiko Adachi, Hideki Nakagome, Tohru Kamo, Kaneshi Taniguchi

Research output: Contribution to conferencePaperpeer-review

Abstract

Tantalum capacitor is a small-sized and has large capacity, and is indispensable for electric equipment. The demand increases year by year, and a quite large number of used tantalum capacitors is generated. Recovery of tantalum from tantalum condenser is recently important since production of tantalum have not been stable for the price and the quality. However, recovery of tantalum from tantalum-condenser is difficult since tantalum parts strongly cover with the flame retardant resin made of halogenated compound (mold resin). This research investigated recovery of tantalum parts from tantalum condenser using steam gasification with mixed molten carbonate. Mixed molten carbonate (Na2CO3:K2CO3:Li2CO3 = 1:1:1) (3 g) put into the reactor, and heated with electric furnace while flowing nitrogen (160 mL/min) and steam (1 mL/min) warmed by heater. After heating to setting temperature (450-650 oC), tantalum condenser (3 g) was put into the reactor, heated for 5-10 min, and then cooled to room temperature to recover the reacted capacitor by filtration after treating with distilled water. At relatively low temperature (550 oC) heating for 10 min, mold resin can be decomposed by using steam gasification with mixed molten carbonate, in comparison with using pyrolysis and steam gasification without carbonate, and decomposition reaction occurred over 500 oC by using steam gasification with mixed carbonate. Recovery of tantalum parts from capacitor is successful using steam gasification with mixed molten carbonate at 530 oC for 5 min, due to the effective decomposition and removal of mold resin from capacitor. Furthermore, most halogen gas generated from decomposition of mold resin can be trapped in molten carbonate not to exhaust halogen gas. These results suggested that recovery process of tantalum parts from used condenser using steam gasification with mixed molten carbonate is expected as a feasible way to recycle the rare metal in electric equipment.

Original languageEnglish
Publication statusPublished - 2014
Externally publishedYes
Event27th International Mineral Processing Congress, IMPC 2014 - Santiago, Chile
Duration: 2014 Oct 202014 Oct 24

Other

Other27th International Mineral Processing Congress, IMPC 2014
Country/TerritoryChile
CitySantiago
Period14/10/2014/10/24

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology
  • Mechanical Engineering

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