Journal of Conservation Science (보존과학회지)

The Korean Society Of Conservation Science For Cultural Heritage (한국문화재보존과학회)
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Experimental Study of Desalting Methods Using Ethyl Alcohol for Archaeological Cast Iron Objects

에틸알코올 용매를 이용한 주조철제유물의 탈염 실험 연구

  • Lee, Hye Youn (Naju National Research Institute of Cultural Heritage) ;
  • Cho, Ju Hye (National Research Institute of Cultural Heritage)
  • 이혜연 (국립나주문화재연구소) ;
  • 조주혜 (국립문화재연구소 복원기술연구실)
  • Received : 2015.04.26
  • Accepted : 2015.06.08
  • Published : 2015.06.20
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Abstract

Excavated archaeological cast iron objects in improper storage are quickly corroded and disintegrated into block and powder finally. Hence desalination treatment which is a way of removing internal corrosive factors, especially chloride ion, is an important process. But desalination is often omitted or objects are dehydrated by alcohol because the destruction of objects could occur during desalting. Although current desalting methods mostly use an aqueous alkali solution, $OH^-$ ions of water could accelerate corrosion and broaden internal cracks cause of high surface tension. Therefore this study experimented desalting using ethyl alcohol, which is low surface tension, to investigate an effect of desalination. As a result, desalting using ethyl alcohol showed the similar or more effective results of desalting using water. In addition, as aspects of desalting safety, ethyl alcohol desalting method was smaller destruction of objects and extraction of Fe from the objects than the aqueous alkali solution. However, this study explored the possibility of desalting methods using organic solvent in fieldwork, so the results would provide basic date for making the safe and effective desalting method for archaeological cast iron objects through further experiments.

주조철제유물은 발굴 후 보존환경이 맞지 않은 경우 부식이 급속하게 진행되며 특히 블록형 파손이 발생하고 최종에는 분말화 된다. 따라서 부식 요인, 즉 $Cl^-$ 이온을 제거하는 탈염처리가 중요하다. 그러나 주조철제유물은 탈염과정 중 형태가 파손되는 경우가 빈번히 발생하여 탈염 과정을 생략하거나 탈수 등의 안정화처리로 그치는 경우가 많다. 기존의 탈염 방법은 주로 물을 이용한 알칼리 수용액 방법이다. 그러나 물의 수산화이온은 부식을 촉진시키고 높은 표면 장력으로 내부 균열을 확대시켜 주조철제유물의 탈염 과정 중 파손 원인으로 판단된다. 따라서 본 연구에서는 표면 장력이 낮은 에틸알코올을 이용하여 탈염을 실시하고 그 탈염 효과를 알아보았다. 실험 결과 에틸알코올 탈염방법은 상온의 알칼리 수용액 방법과 유사하거나 더 높은 $Cl^-$ 이온 용출 효과를 보여주었다. 또한 에틸알코올 방법은 수용액 방법보다 유물의 파손이 적고 Fe의 용출이 거의 없어 탈염의 안전성 측면에서 우수함을 확인하였다. 본 실험은 현장적용 가능한 유기 용매 탈염 방법을 검토한 것으로 추가 연구를 통하여 주조철제유물의 안전하고 효율적인 안정화 방안을 마련하고자 한다.

Keywords

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