| dc.description.abstract | Cobalt is classed by most developed countries as a critical raw material. Its economic importance is increasing owing to its use in the electric vehicle batteries essential for the energy transition. However, there is a risk of supply disruption and shortage, due in part to the by-product nature of cobalt but also especially to the concentration of the global supply chain in Democratic Republic of the Congo (DRC) (primary mining) and China (processing). This thesis investigates the opportunities and challenges of increasing the supply of cobalt from European primary and secondary resources, while also following good practice for sustainable and responsible mining.
For the first part of this thesis, a review and resource inventory of cobalt-bearing deposits across Europe, in collaboration with several overseas geological surveys, revealed that there is a large geological potential for cobalt. A total of 1 342 649 tonnes of cobalt metal were identified and classified based on development status by using the Unite Nations Framework classification. Resources are hosted in different deposit types, chiefly magmatic Ni-Cu sulfide deposits, metasediment-hosted Cu-Co-Au, black shale-hosted deposits in Fennoscandia and Ni-Co laterite deposits in the Balkans and Turkey. However, the majority of these resources are associated with high uncertainties in their estimates and only 8% are currently considered commercially viable to be mined for cobalt.
The second part of this thesis focusses on selected exploration projects and used multicriteria analysis to assess political and legal, environmental, social and economic factors that may influence mine development. The analysis included several projects in Finland, Norway and Sweden, which all have well-established mineral governance, ensuring good environmental protection and societal trust in government decisions. However, many of these are situated in the vulnerable ecosystem of the Arctic and impact the local indigenous people. Turkish laterite deposits (i.e. Çaldağ) have the opportunity to reach high metal recoveries through hydrometallurgical processing (94% Co), but Turkey’s mineral governance is judged here as insufficient to sustainably manage environmental and social impacts from mining. In all projects, gaining the social license to operate is
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essential for sustainable project development and therefore these projects are also considered high risk.
The third part carried out fieldwork and laboratory analyses to determine the cobalt deportment and consider therefore the resource potential from remaining ore and mine waste of two historic volcanogenic massive sulfide mine sites in Løkken, Norway and the Troodos ophiolite complex in Cyprus. Both have a long history of copper and sulfur production, but cobalt was never extracted from the ore. Our analyses showed, that cobalt is dominantly hosted in zoned pyrite (up to 5.1 wt. % Co). Analysed mine waste at Løkken, also hosts cobalt dominantly in residual pyrite, as well in sulfides and olivine phases in slags from earliest mine waste (~ before 1900). Nevertheless, modern tailings (1974 – 1987) are likely to be the most promising secondary resource as pyrite ended up in the tailings during copper-zinc production. Despite these promising results, it is uncertain if these resources are economically recoverable due to large knowledge gaps, and environmental concerns around reprocessing secondary resources.
While there are many cobalt-bearing deposits in Europe as well as potential resources in mine waste, the associated environmental, social and governance aspects can have large impacts on the future supply potential of these resources and Europe will likely remain dependent on imports in the near future. | en_GB |
