The environmental performance of mining operations: Comparison of alternative mining solutions in a life cycle perspective

Frédéric Lai (1) , Antoine Beylot (1) , Rafael Navarro , Peter Schimek , Philipp Hartlieb , Daniel Johansson (2) , Pablo Segarra , Celso Amor , Jacques Villeneuve (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 LUT - Luleå University of Technology = Luleå Tekniska Universitet

Mining represents the first step to the access to mineral resources. The impacts induced by such operations now contribute to the impacts of a wide range of goods and services, given the widespread use of these raw materials in the worldwide economy. In this context, this study aims at assessing the environmental performance of mining operations in a life cycle perspective, considering two currently operating mine sites: the Erzberg iron open-pit mine (Austria) and the Lujar fluorspar underground mine (Spain). In particular, this study aims at i) identifying the main environmental hotspots along the cradle-to-gate exploitation of mineral deposits in these two mines (“reference scenarios”), ii) assessing the environmental performance of two alternative mining solutions (“alternative scenarios”), respectively the use of alternative explosive compositions (including their associated air emissions) and the implementation of a new blast design method. This assessment relies on representative sets of data primarily drawn from on-site operations and experimental results, completed with other data sources to fill the gaps. The environmental impacts are characterized based on the European EF (Environmental Footprint) life cycle impact assessment method. Firstly, among the 16 impact categories considered, the production of 1 ton of iron concentrate (33.5% Fe) in the Erzberg mine in particular potentially induces a total of 8.75 kg CO2-eq. The consumption of ferrosilicon in the concentration step (main contributor to 8 impact categories out of 16), of steel in the comminution step (main contributor to 2 impact categories), and of diesel by the machinery necessary for loading/hauling the ore (main contributor to 3 impact categories) stand for the main environmental hotspots in the Erzberg case. Secondly, the production of 1 ton of fluorspar concentrate (79.2% CaF2) in the Lujar mine potentially induces a total of 174 kg CO2-eq. The consumption of diesel by the machinery and the on-site generators in the mining and loading/hauling steps (main contributor to 11 impact categories out of 16), along with the mine infrastructure/equipment (main contributor to 4 impact categories) are identified as the main environmental hotspots in the Lujar case. The implementation of both alternative mining solutions results in relatively limited environmental effects on the overall life cycle environmental performance of the Erzberg mining operations (less than 3% difference in terms of impacts). Finally, this study highlights that some challenges still remain to be addressed in order to better secure the use of life cycle assessment in the mining context, in particular in terms of data monitoring/measurement or impact assessment methods

Domaines: Sciences de la Terre

Frédéric Lai, Antoine Beylot, Rafael Navarro, Peter Schimek, Philipp Hartlieb, et al.. The environmental performance of mining operations: Comparison of alternative mining solutions in a life cycle perspective. Journal of Cleaner Production, 2021, 315, pp.128030. ⟨10.1016/j.jclepro.2021.128030⟩. ⟨hal-03745561⟩