화학공학소재연구정보센터
Clean Technology, Vol.23, No.2, 158-162, June, 2017
염화철 에칭 용액 재생을 위한 액상 및 고상 산화제를 이용한 산화공정에 대한 연구
Oxidation Process for the Etching Solution Regeneration of Ferric Chloride Using Liquid and Solid Oxidizing Agent
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초록
철, 구리, 알루미늄, 니켈 등의 금속을 에칭하기 위한 에칭액으로 FeCl3 용액이 사용되며, 에칭 과정에서 Fe3+가 Fe2+로 환원 되면서 에칭속도를 저하시키고, 에칭효율이 감소하게 된다. 또한 에칭 후 발생하는 염화철 에칭폐액은 환경적, 경제적으로 문제를 지니기 때문에 에칭액을 재생하여 재사용 할 필요가 있다. 본 연구에서는 FeCl2 용액에 HCl을 첨가한 후, 산화제로 H2O2, NaClO3를 첨가하여 용액 내 Fe2+를 산화시켰으며, 산화과정에서 산화-환원전위(ORP)와 산화율간의 관계를 조사하였다. ORP는 H2O2와 NaClO3의 농도가 증가함에 따라 증가하였으며, 산화가 진행되면서 점차 감소하여 산화가 완료된 후에 일정한 ORP를 유지하였다. Nernst 식과 일치하는 결과를 보였다. 또한 충분한 양의 HCl 및 H2O2, NaClO3를 첨가하였을 경우, 약 99% 이상 산화가 이루어짐을 알 수 있었다.
FeCl3 solution has been used as an etchant for metal etching such as Fe, Cu, Al and Ni. In the etching process, Fe3+ is reduced to Fe2+ and the etching efficiency is decreased. Waste FeCl3 etchant has environmental, economic problems and thus the regeneration of the etching solution has been required. In this study, HCl was mixed with the FeCl2 solution and then, H2O2, NaClO3 were added into the mixed solution to oxidize the Fe2+. During the oxidation process, oxidation-reduction potential (ORP) was measured and the relationship between ORP and oxidation ratio was investigated. The ORP is increased with increasing the concentration of H2O2 and NaClO3, and then the ORP is decreased with oxidation progress. Such a behavior was in good agreement with Nernst’s equation. Also, the oxidation efficiency was about 99% when a sufficient amount of HCl and H2O2, NaClO3 were added.
  1. Lee HM, Park M, Park GH, Park C, Korean Chem. Eng. Res., 50(2), 211 (2012)
  2. Allen DM, Ler LT, J. Environ. Monit., 1, 103 (1999)
  3. Lee H, Ahn E, Park C, Tak Y, Appl. Chem. Eng., 24(1), 67 (2013)
  4. Ler LT, “Oxygen as a Potential Etchant Regenerator,” MS Dissertation, Cranfield Institute of Technology, Bedford (1993).
  5. Allen DM, Ler LT, PCMI J., 59, 3 (1995)
  6. Ler LT, “Measurement and Reduction of the Environmental Impact of Industrial Photochemical Maching,” Ph.D. Dissertation, Cranfield Institute of Technology, Bedford (1998).
  7. Peter A, “Automated Oxygen Regeneration of Ferric Chloride Etchant,” Ph.D. Dissertation, Cranfield Institute of Technology, Bedford (1999).
  8. Allen DM, Almond HJA, J. Mater. Process Technol., 149, 238 (2014)
  9. Yoo K, Jha MK, Kim MS, Yoo JM, Jeong J, Lee JC, J. Korean Inst. Resour. Recycl., 17(1), 80 (2008)