This study showed that the emerging application of Supercritical Fluid (SCF) Extraction can be used to rapidly stabilize batches of corroded ferrous metal artifacts, including cast and wrought iron and steel, as well as composite artifacts. This will allow labs to avoid or safely delay traditional electrochemical techniques operation, allowing groups of small artifacts to be quickly stabilized and consolidated, potentially even in field settings. The process may also be tailored to treat objects from sites with soil contamination or materials from heritage collections, where potentially hazardous chemicals are also extracted during dewatering. While critically important questions remain to be addressed before the technique can be made systematically operational, particularly those surrounding chloride salts, the technique has tremendous potential to improve best practices in metals conservation. Our proof-of-concept experiments allowed us to improve our procedures for the next phase of development.
Students and faculty disseminated their findings at four separate archaeological and conservation conferences where results could be disseminated to different professional communities. Team members also prepared blog posts about their experiments targeted to public audiences. The project established a sustained collaborative relationship between the Departments of Social Sciences, materials Science and Engineering, and Chemical Engineering at Michigan Technological University. project Scientists also developed professional connections with practicing conservators for future collaborations.
This research was made possible through a grant from the National Center for Preservation Technology and Training (NCPTT).