Accelerated galvanic corrosion between graphitic rock from underground mines and metal coupons

Authors: Stazick, C; Feagan, G; Sunderman, S Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2325_29

Cite As:
Stazick, C, Feagan, G & Sunderman, S 2023, 'Accelerated galvanic corrosion between graphitic rock from underground mines and metal coupons', in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 439-450, https://doi.org/10.36487/ACG_repo/2325_29



Abstract:
Dissimilar materials, such as steel and graphite, can experience galvanic corrosion resulting in safety hazards for many industries. Rock samples from a United States mine that exhibits electrochemical properties similar to graphite were galvanically coupled to corrosion coupons in an accelerated environment. Traditional weight loss and potentiostatic measurements were utilised to investigate the rock’s observed in situ influence on metal comparable to underground support (e.g. rockbolts or steel mesh). Corrosion rates of the galvanically coupled coupons were multiple times higher than the coupons in the standard solution alone, with coupons held at higher temperature and humidity experiencing the most aggressive degradation over the testing period. Surface analysis of samples revealed extensive pitting of the steel, resembling failed bolt samples from partner mines. Metallic ground support in contact with graphitic rock has a higher potential for severe corrosion rates that could lead to premature failure of the ground support and ultimately pose a safety threat to mine workers without intervention.

Keywords: corrosion, galvanic corrosion, metal ground support

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