FeCl 3 용액은 금속의 에칭용액으로 사용되며, 사용 후 발생하는 FeCl 3 에칭폐액은 환경적, 경제적으로 문제를 지니기 때문에 에칭액을 재사용할 필요가 있다. 본 연구에서는 FeCl 2 용액에 HCl을 첨가 한 후, 산화제로 H 2 O 2 를 첨가하여 용액 내 Fe 2+ 를 산화시켰으며, 산화과정에서 산화-환원전위(ORP)와 산화율 간의 관계를 조사하였다. ORP는 HCl과 H 2 O 2 의 농도가 증가함에 따라 증가하였으며, 산화가 진행되면서 점차 감소하여 Nernst 식과 일치하는 결과를 보였다. 또한 충분한 양의 HCl과 H 2 O 2 를 첨가하였을 경우, 약 99% 이상 산화가 이루어짐을 알 수 있었다.

The FeCl 3 solution has been used as an etchant for etching of metal. It is necessary to reuse the etching solution because waste FeCl 3 etchant generated after use has provided environmental and economic problems. In this study, HCl was mixed with the FeCl 2 solution and then H 2 O 2 was added into the mixed solution to oxidize the Fe 2+ . During the oxidation process, oxidationreduction potential (ORP) was measured and the relationship between ORP and oxidation ratio was investigated. As a result, this study found that the ORP was increased with increasing the concentration of HCl and H 2 O 2 , while the ORP is decreased with oxidation progress. Such a behavior was in good agreement with Nernst’s equation. Also, the oxidation efficiency reached about 99% when a sufficient amount of HCl and H 2 O 2 were added.