Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Electrochemical Behavior of Tin and Silver during the Electrorecycling of Pb-free Solder (Sn-Ag-Cu) Waste

폐무연솔더(Sn-Ag-Cu)의 전해재활용 시 주석과 은의 전기화학적 거동 연구

  • Kim, Min-seuk (Resources Utilization Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Lee, Jae-chun (Resources Utilization Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Kim, Rina (Resources Utilization Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Chung, Kyeong-woo (Resources Utilization Division, Korea Institute of Geoscience and Mineral Resources)
  • 김민석 (한국지질자원연구원 자원활용연구본부) ;
  • 이재천 (한국지질자원연구원 자원활용연구본부) ;
  • 김리나 (한국지질자원연구원 자원활용연구본부) ;
  • 정경우 (한국지질자원연구원 자원활용연구본부)
  • Received : 2022.04.04
  • Accepted : 2022.05.15
  • Published : 2022.06.30
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Abstract

We investigated the electrochemical behavior of Sn (93.0 %)-Ag (4.06 %)-Cu (0.89 %) during electrolysis of Pb-free solder waste to recover tin and silver. A thin strip of the solder waste produced by high-temperature melting and casting was used as a working electrode to perform electrochemical analysis. During anodic polarization, the current peak of an active region decreased with an increase in the concentration of sulfuric acid used as an electrolyte. This resulted in the electro-dissolution of the working electrode in the electrolyte (1.0 molL-1 sulfuric acid) for a constant current study. The study revealed that the thickening of an anode slime layer at the working surface continuously increased the electrode potential of the working electrode. At 10 mAcm-2, the dissolution reaction continued for 25 h. By contrast, at 50 mAcm-2, a sharp increase in the electrode potential stopped the dissolution in 2.5 h. During dissolution, silver enrichment in the anode slime reached 94.3% in the 1 molL-1 sulfuric acid electrolyte containing a 0.3 molL-1 chlorine ion, which was 12.7% higher than that without chlorine addition. Moreover, the chlorine enhanced the stability of the dissolved tin ions in the electrolyte as well as the current efficiency of tin electro-deposition at the counter electrode.

주요성분이 Sn(93.0 %)-Ag(3.26 %)-Cu(0.89 %)로 구성되는 SAC 폐무연솔더로부터 주석과 은을 회수하기 위한 전기화학적인 방법을 연구하였다. 폐무연솔더의 건식용해, 주조를 통해 제조한 작업전극을 사용하여 분극거동 조사와 정전류 전해용해를 실시하였다. 분극시험 시 활성화영역의 산화전류피크는 전해액의 황산 농도가 높아질수록 감소하였으며, 1 molL-1 황산농도가 전해용해를 위해 가장 적절한 것으로 나타났다. 정전류 용해 시 전극표면의 부동태층인 양극슬라임이 두꺼워짐에 따라 전극전위가 지속적으로 높아졌으며, 10 mAcm-2에서 25시간동안 지속적인 전해용해가 가능한 반면 50 mAcm-2에서는 2.5 시간 이후부터 전극전위가 급상승하여 전해용해반응이 중단되었다. 정전류 전해용해 시 은은 양극슬라임에 농축되었으며, 전해액내 염소이온의 농도가 0.3 molL-1인 경우 농축율이 미첨가 조건보다 12.7% 높은 94.3%를 나타내었다. 또한 염소이온의 첨가에 의해 전해액내 주석이온의 안정성을 높이고 주석의 전착전류효율을 향상시킬 수 있었다.

Keywords

Acknowledgement

본 연구는 한국지질자원연구원 주요사업인 '국내 부존 바나듐(V) 광물자원 선광/제련/활용기술 개발(GP2020-013)' 과제의 일환으로 수행되었습니다. 이에 감사드립니다.

References

  1. Jae-chun Lee, Jinki Jeong, Byung-su Kim, et. al., 2010 : Development of Technology for the Recycling of Urban Ore, Korea Institute of Geoscience and Mineral Resources, pp.31.
  2. Ministry of Environment, http://www.me.go.kr/wonju/web/board/read.do?menuId=1032&boardMasterId=232&boardCategoryId=305&boardId=293348, June 14, 2022.
  3. Hiren R. Kotadia, Philip D. Howes, Samjid H. Mannan, 2014 : A review: On the development of low melting temperature Pb-free solders, Microelectronics Reliability, 54, pp.1253-1273. https://doi.org/10.1016/j.microrel.2014.02.025
  4. H. Takahashi, T. Tanaka, M. Hamada, et. al., 2009 : Novel Recycle System of Solder Paste, 10th Int. Symp. on East Asian Res. Recycl. Tech., pp.761-764.
  5. Byung-Su Kim, Jae-chun Lee, Soo-Kyung Kim, 2010 : A Novel Cyclic Process Involving Zinc for Separating Silver from Lead-Free Solder Residue, Materials Transactions, 51, pp.1350-1353. https://doi.org/10.2320/matertrans.M2010128
  6. Kyoungkeun Yoo, Jae-chun Lee, Kwang-sek Lee, et. al., 2012 : Recovery of Sn, Ag and Cu from Waste Pb-Free Solder Using Nitric Acid Leaching, Materials Transactions, 53, pp. 2175-2180. https://doi.org/10.2320/matertrans.M2012268
  7. Seong-Hyung Ryu, Jae-Woo Ahn, Hyo-Jin Ahn, et al., 2014 : Recovery of Tin and Copper from Waste Solder Stripper by Oxalate Precipitation, J. of Korean Inst. of Resources Recycling, 23, pp.37-43.
  8. Sookyung Kim, Jae-chun Lee, Kwang-sek Lee, et. al., 2014 : Separation of Tin, Silver and Copper from Waste Pb-free Solder Using Hydrochloric Acid Leaching with Hydrogen Peroxide, Materials Transactions, 55, pp.1885-1889. https://doi.org/10.2320/matertrans.M2014289
  9. Sang-hun Lee, Kyoungkeun Yoo, Manis Kumar Jha, et. al., 2015 : Separation of Sn from waste Pb-free Sn-Ag-Cu solder in hydrochloric acid solution with ferric chloride, Hydrometallurgy, 157, pp.184-187. https://doi.org/10.1016/j.hydromet.2015.08.016
  10. Ki-Woong Lee, Hong-In Kim, Hyo-Jin Ahn, et al., 2015 : Produce of High Purity Tin from Spent Solder by Electro Refining, J. of Korean Inst. of Resources Recycling, 24, pp.62-68. https://doi.org/10.7844/kirr.2015.24.2.62
  11. Peter A. Mright, 1982 : Extractive Metallurgy of Tin, 2nd Edition, Elsevier Scientific Publishing Company, New York, pp.241-242.
  12. Tamas Kekesi, 2013 : Electrorefinning in aqueous chloride media for recovering tin from waste materials, Acta Metallurgica Slovaca, 19(3), pp.196-205. https://doi.org/10.12776/ams.v19i3.161
  13. Zsolt Dobo, T. Kulcsar, T. Kekesi, 2012 : Electrorefinning of tin in pure acid solutions by mechanically controlled cathode deposition and solar power utilization, Materials Science and Engineering, 37(2), pp.19-26.
  14. Digby D. Macdonald, Patrik Schmuki, 2007 : Encyclopedia of Electrochemistry/ Volume 5 Electrochemical Engineering, pp. 219-220, WILEY-VCH Verlag GmbH & Co. KGaA, Weinnheim.
  15. Jae-chun Lee, Dae-hyeong Kim, Min-seuk Kim, et al., 2009 : Development of Technology for the Recycling of Urban Ore, pp.203-205, Korea Institute of Geoscience and Mineral Resources.
  16. Denny A. Jones, 1996 : Principles and Prevention of CORROSION, 2nd Edition, Prentice Hall, Upper Saddle River, NJ, pp.119-121.
  17. Allen J. Bard, Roger Parsons, Joseph Jordan, 1985 : Standard Potentials in Aqueous Solution, MARCEL DEKKER, INC., New York, pp.217, 307
  18. M. Bojinov, K. Salmi, G. Sundholm, 1993 : Impedance measurements o f a t in e lectrode i n H2SO4 solutions, J. Electroanal. Chem., 347, pp.207-221. https://doi.org/10.1016/0022-0728(93)80089-Z
  19. J. W. Johnson, E. C. Liu, 1974 : The anodic dissolution of tin in acidic chloride solutions, J. of the less-Common Metals, 34, pp.113-120. https://doi.org/10.1016/0022-5088(74)90220-3