Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
권호 표지

Regeneration of Waste Ferric Chloride Etchant Using HCl and $H_2O_2$

HCl과 $H_2O_2$를 이용한 폐 $FeCl_3$ 에칭액의 재생

  • Lee, Hoyeon (Department of Chemical Engineering, Inha University) ;
  • Ahn, Eunsaem (Department of Chemical Engineering, Inha University) ;
  • Park, Changhyun (Department of Chemical Engineering, Inha University) ;
  • Tak, Yongsug (Department of Chemical Engineering, Inha University)
  • 이호연 (인하대학교 공과대학 화학공학과) ;
  • 안은샘 (인하대학교 공과대학 화학공학과) ;
  • 박창현 (인하대학교 공과대학 화학공학과) ;
  • 탁용석 (인하대학교 공과대학 화학공학과)
  • Published : 2013.02.10

Abstract

$FeCl_3$ has been used as an etchant for metal etching such as Fe, Cu, and Al. In the process of metal etching, $Fe^{3+}$ is reducted to $Fe^{2+}$ and the etching rate becomes slow and etching efficiency decreased. Waste $FeCl_3$ etchant needs to be regenerated because of its toxicity and treatment cost. In this work, HCl was initially mixed with the waste $FeCl_3$ and then, strong oxidants, such as $O_2$ and $H_2O_2$, were added into the mixed solution to regenerate the waste etchant. During successive etching and regeneration processes, oxygen-reduction potential (ORP) was continuously measured and the relationship between ORP and etching capability was investigated. Regenerated etchant using a two vol% HCl of the total etchant volume and a very small amount of $H_2O_2$ was very effective in recovering etching capability. During the etching-regeneration process, the same oxygen-reduction potential variation cannot be repeated every cycle since concentrations of $Fe^{2+}$ and $Fe^{3+}$ ions were continuously changed. It suggested that the control of etching-regeneration process based on the etching time becomes more efficient than that of the process based on oxygen reduction potential changes.

Keywords

ferric chloride;hydrogen peroxide;Fenton reaction;etching;regeneration

References

  1. L. T. Ler, Oxygen as a potential etchant regenerator, MS Thesis, Cranfield Institute of Technology, Bedford, UK (1993).
  2. D. M. Allen and L. T. Ler, PCMI J., 59, 3 (1995).
  3. L. T. Ler, Measurement and reduction of the environmental impact of industrial photochemical maching, PhD Thesis, Cranfield Institute of Technology, Bedford (1998).
  4. A. Peter, Automated oxygen regeneration of ferric chloride etchant, PhD Thesis, Cranfield Institute of Technology, Bedford (1999).
  5. H. Lim, K. C. Namkung, and J. Yoon, J. Korean Ind. Eng. Chem., 16, 9 (2004).
  6. B. G. Kwon and J. Yoon, J. Korean Ind. Eng. Chem., 20, 593 (2009).
  7. D. M. Allen, The Principles and Practice of Photochemical Machining and Photetching, IOP Publishing Ltd., Bristol, UK (1986).
  8. Z. Qiang, J. Chang, and C. Huang, Water Res., 37, 1308 (2003). https://doi.org/10.1016/S0043-1354(02)00461-X
  9. D. M. Allen and H. J. A. Almond, J. Mater. Process. Technol., 149, 238 (2004). https://doi.org/10.1016/j.jmatprotec.2004.02.044
  10. D. M. Allen and P. Jefferies, Ann. CIRP, 55, 1 (2006). https://doi.org/10.1016/S0007-8506(07)60353-9
  11. Z. Wang, J. Che, and C. Ye, Hydrometallurgy, 105, 69 (2010). https://doi.org/10.1016/j.hydromet.2010.07.013
  12. D. M. Allen, Process. Adv. Mat., 1, 69 (1991).