Abstract

COELHO, J. C.; OLIVEIRA, C. M.; CARVALHO, M. D.  and  FONSECA, I. T. E.. The efficiency of the electrochemical techniques for the removal of chloride ions from samples of a cannon ball from a shipwreck of the xviii century. Corros. Prot. Mater. [online]. 2012, vol.31, n.1, pp.05-12. ISSN 2182-6587.

For the conservation of archeological iron marine artefacts, electrochemical methods have been tested, namely, the electrolytic and the galvanic reduction. Results were compared with the classical methods of simple immersion in alkaline solutions and the alkaline sulfite reduction. Experiments were performed on samples prepared from a cannon ball made with cast iron of the XVIII century, found in the archaeological context of a shipwreck, of the l`Ócean, which has occurred near the coast in the south of Portugal, in 1759. Before and after the application of the various treatments samples (core and corrosion products) have been analyzed by X-rays diffraction spectroscopy, scanning electron microscopy and X-rays electron dispersion spectroscopy. The efficiency of the methods for the extraction of chloride ions has been evaluated by the analysis performed by ionic chromatography. It was concluded that under identical conditions the electrolytic reduction was the method leading to the highest efficiency.

Keywords : Archaeological Iron; Electrochemical Methods; Chloride Ions Extraction.

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