Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Leaching of copper and silver from ground mobile phone printed circuit boards using nitric acid

핸드폰 기판(基板)으로부터 구리와 은의 질산(窒酸) 침출(浸出) 연구(硏究)

  • Le, Long Hoang (Department of Resources Recycling, Korea University of Science and Technology) ;
  • Yoo, Kyong-Keun (Minerals and Materials Processing Division, KIGAM) ;
  • Jeong, Jin-Ki (Minerals and Materials Processing Division, KIGAM) ;
  • Lee, Jae-Chun (Minerals and Materials Processing Division, KIGAM)
  • ;
  • 유경근 (한국지질자원연구원 자원활용소재연구부) ;
  • 정진기 (한국지질자원연구원 자원활용소재연구부) ;
  • 이재천 (한국지질자원연구원 자원활용소재연구부)
  • Published : 2008.06.27
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Abstract

Leaching of copper and silver from mobile phone PCBs(printed circuit boards) with nitric acid was performed to investigate the effects of nitric acid concentrations, leaching temperatures, agitation speeds, and pulp densities on the leaching behaviors of Cu and Ag. The leaching rate considerably increased with increasing acid concentration and temperature. The leaching ratios of Cu and Ag were found to be 96.4% and 96.5%, respectively, under the optimum condition; at $80^{\circ}C$ with 2mol/L $HNO_3$ and 120g/L in pulp density within 39minutes. The kinetic parameters were determined based on the shrinking core model with reaction control corresponding to small particles. The activation energies for the leaching of copper and silver were found to be 45.5kJ/mol and 60.5kJ/mol at $35{\sim}80^{\circ}C$ with 2mol/L $HNO_3$, respectively.

핸드폰 기판 내 구리와 은의 침출거동에 미치는 질산농도, 반응온도, 교반속도, 광액농도의 영향을 조사하기 위하여 질산을 이용한 핸드폰 기판침출실험을 수행하였다. 질산농도와 반응온도의 증가에 따라 침출율은 빠르게 증가하였다. 최적 침출 조건인 $80^{\circ}C$, 2mol/L $HNO_3$, 120g/L의 조건에서 구리와 은의 침출율은 반응시간 20분 동안 $98{\sim}99%$에 달하였다. 수축핵 모델(Shrinking core model)에 기초하여 각 침출실험결과를 분석하고 속도상수를 결정하였다. 활성화에너지는 2mol/L 질산용액을 이용하여 온도범위 $35{\sim}80^{\circ}C$에서 분석한 결과, 구리와 은에 대하여 각각 45.5kJ/mol과 60.5kJ/mol을 나타내었다.

Keywords

References

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