Content uploaded by Giorgia Stasi
Author content
All content in this area was uploaded by Giorgia Stasi on Jan 17, 2020
Content may be subject to copyright.
European Geologist Journal 47
Exploration of flooded mines as support to the battery
industry and the energy transition in Europe
By Giorgia Stasi*, Isabel Fernandez, Yves Vanbrabant
* RBINS – Geological Survey of Belgium, Rue Jenner 13, Brussels 1000, Belgium
gstasi@naturalsciences.be
Abstract
The transition to renewable energy needs minerals to build wind, solar, and battery
technology for energy production and storage. In order to help the development of this sector
and to maintain and enhance the possibility of the EU to become more independent from the
import of raw materials we need to improve the research activity for both known and
undiscovered mineralization. For this purpose, the UNXEMIN project is developing
autonomous submersible robots to explore, map and characterize abandoned flooded mines
in Europe. Along with robot development, the first inventory of flooded mines in Europe has
been created, that now contains more than 8,000 entries from 24 countries. This database
can be used in the European industrial framework as a resource for research in specific critical
raw materials.
UNEXMIN as support to the battery industry in Europe
The UNEXMIN project is developing autonomous submersible robots to explore, map and
characterize abandoned, underground flooded mines in Europe. These robots will be able to
map and sample underground flooded mines at up to 500 m depth. But how can the UNEXMIN
project help Europe in the energy transition?
The transition to renewable energy needs wind, solar and battery technology, which require
a lot of minerals. Renewable energies like water, solar and wind power are often not
continuously available, so efficient interim storage is necessary to ensure a steady supply of
power. Battery storage systems are an advantageous option in this regard. The EU is highly
dependent on imports of metallic minerals, as its domestic production is limited to about 3%
of world production (COM (2008) 699). One of the main goals of Europe is to reduce the
dependency on the import of raw materials and solve issues along the entire value chain. This
project could steer the EU to the forefront in sustainable minerals surveying and exploration
technologies; it can increase Europe’s capacity to re-evaluate its abandoned mines for their
mineral potential, with reduced exploration cost and increased investment security for any
future mining operations (Lopes et al., 2017).
Battery development and production is a strategic imperative for Europe in the context of the
clean energy transition. There is a strong need to create competitive and sustainable battery
manufacturing in Europe. Working towards this goal, the European Commission is promoting
a cross-border and integrated European approach covering the whole value chain of the
battery ecosystem and focusing on sustainability, starting with the extraction and processing
of raw materials, the design and manufacturing phase of battery cells and battery packs and
their use, second use, recycling and disposal in a circular economy context. The Strategic
Action Plan on batteries (COM (2018)293 Annex 2) combines targeted measures at EU level
including the areas of raw materials (primary and secondary), research and innovation,
financing/investment, standardisation/regulation and trade and skills development. The aim
is to make Europe a global leader in sustainable battery production and use, in the context of
the circular economy. More specifically it aims to facilitate access to European sources of raw
materials and to secure access to raw materials from resource-rich countries outside the EU
(COM (2008) 699). The policy is also based on sustainable domestic raw materials production
and resource efficiency and supply of secondary raw materials.
Critical raw materials for batteries
At present, optimised LIB (Lithium Ion Batteries) cells represent the core technology for
energy storage. The supply of critical raw materials for LIB is ensured by working along three
routes: sourcing from third countries developing domestic sourcing; and promoting recycling
of battery materials as well as reuse of batteries. The sourcing of the four essential raw
materials (cobalt, lithium, nickel and graphite) is concentrated in only a few countries (Figure
1). The Democratic Republic of Congo is the source of 64% of the global supply of cobalt and
Chile is the main supplier of lithium with 36%.
Figure 1: Countries supplying critical raw materials for batteries, amount (tonnes) and
percentage of global supply (from EC SDW (2018)).
In the EU countries Finland is a major supplier of refined cobalt (it meets 66% of EU demands
for ores and concentrates); however, the extent of domestic sourcing of EU demand is very
limited for the other materials (nickel and lithium) (COM (2018)293 Annex 2).
In order to help the development of this sector and to maintain and enhance the possibility
of EU to become more independent from the import of raw materials, an improvement in
research activity for known and undiscovered mineralisation of the targeted materials (cobalt,
lithium, nickel and graphite) is needed and expected.
The current status of mineral exploration activities for battery applications is shown in Figure
2 (EC SWD(2018)); activities remain concentrated in Portugal, Finland, Sweden and Central
Europe.
Figure 2: Status of mineral exploration activities for cobalt, graphite, lithium and nickel in
2017 (from EC SDW (2018)).
UNEXMIN inventory of flooded mines as a research tool
In the UNEXMIN project, along with the robot construction, project participants are carrying
out a comprehensive inventory of underground flooded mines in Europe. The total number
of flooded mines in Europe is still unknown. Depending on the definition (e.g. fully developed
mine on an industrial scale versus artisanal medieval mining site or individual mine versus
mining district), estimations range from ≈5,000 to >30,000 mines in Europe (ISRM 2008) but
no comprehensive dataset has been available up to now.
In order to gather relevant data for the open-access database of UNEXMIN, information about
flooded mines has been systematically collected by 15 national associations of the European
Federation of Geologists (EFG) and by the Geological Survey of Belgium (RBINS-GSB). The data
were retrieved through the review of existing datasets (ProMine, Minerals4EU), desk research
and automated approaches (manual data extraction and automated data web-crawling). As
the information related to the abandoned mines in Europe is mostly spread among different
authorities, associations or publications, the quantity and the quality of the recovered
information varies from country to country and from mine to mine.
UNEXMIN’s inventory currently covers ~8,100 mines from 24 countries (D5.4, 2018) (Figure
3) and contains information about the mine name(s), its location, its accessibility, the
extracted commodities, the geological information related to the available maps and sections,
the classification of the deposit, the ownership, the activity level, the potential legal
restrictions and other useful information. This new open-access database could be used as a
research tool to identify abandoned mines that could potentially be re-opened in the future.
Figure 3: Web interface of the UNEXMIN database.
Through the web interface of the UNEXMIN database it is possible to select all of the flooded
mines with the targeted minerals as commodities (Figure 4a). At this current stage we count
a total of 72 mines of Li, Co, and Ni as principal or secondary commodities in 10 countries
(Figure 4b).
Figure 4: Selection of UNEXMIN mines for the EU battery industry: a) map distribution of the
mines, b) graph distribution of the mines by mineral and country.
For each mine we have information about the deposit type, the geology of the area, the water
level, the distance from the nearest road, the mine size and the year of the closure. The
majority of the mines were closed at the end of the 19th century or in the middle of the 20th
century, mostly due either to economic reasons or exhaustion of the principal commodity.
Czech Republic
One deposit of nickel as a secondary commodity has been found. This is a syn-deformational
hydrothermal and replacement deposit. The mineral resource was considered exhausted in
1978 but now new exploration can be planned with the brand-new exploration technology.
Finland
As the primary commodity 5 nickel mines, 11 nickel and cobalt mines have been identified,
plus 2 cobalt mines as secondary commodity. Except for one nickel-cobalt deposit of
hydrothermal origin, all the other deposits are of magmatic origin. The two cobalt deposits
are volcanogenic massive sulfide (VMS) deposits, one nickel deposit is associated with
komatiite, and the others are VMS or synorogenic Ni-Cu deposits in (ultra)basic intrusions.
Germany
In Germany 24 underground flooded mines have been found, of which 8 contain lithium, 8
cobalt, 4 nickel and 4 nickel-cobalt. The lithium deposits are of magmatic, hydrothermal and
metasomatic origin: these are porphyry-associated deposits, pegmatitic deposits and skarn
deposits. The cobalt deposits are of hydrothermal origin, and the nickel deposits are VMS, a
layered mafic-ultramafic intrusion deposit and a deposit with marine-sedimentary origin. The
deposits with both nickel and cobalt as principal commodity are classified as porphyry-
associated deposits and fractioned granitoid-associated deposits.
Italy
In Italy 7 nickel mines and 1 nickel-cobalt mine have been found. These deposits have
magmatic origin.
Poland
One nickel mine has been identified in a lateritic-nickel-cobalt deposit.
Portugal
In Portugal there are 3 lithium mines: 2 of magmatic origin, a syn-deformational hydrothermal
and replacement deposit and a pegmatitic deposit; and 1 fractionated granitoid-associated
deposit.
Serbia
In Serbia a skarn deposit with cobalt as a secondary commodity has been found.
Slovakia
In Slovakia there is a layered mafic-ultramafic intrusion deposit with nickel and cobalt as
primary commodities.
Sweden
In Sweden there are 4 nickel-cobalt mines and 1 mine of nickel. One nickel-cobalt mine is
located in a VMS deposit while the others are associated with komatiite, as is the nickel mine.
UK
A total of 4 cobalt mines, 5 nickel mines and 1 nickel-cobalt mine have been found in the UK.
All these mines are in vein type deposits of hydrothermal origin.
Conclusion
Figure 5 graphically represents the UNEXMIN data and the exploration activities in 2017 (EC
SWD(2018) 245/2)[1]. Comparing this graph and the maps (Figures 2 and 4) it is possible to
notice that, while in most of the countries the number of exploration activities in 2017 reflect
approximately the closed or abandoned mines listed in the UNEXMIN inventory, in Germany
there could be the possibility to expand the exploitation of cobalt, lithium and nickel. As the
UNEXIM database is currently being updated it is not possible to compare figures for France
or Spain, but preliminary results suggest that a similar situation will emerge for France.
Figure 5: Distribution of mines among European countries, comparison of selected
UNEXMIN database (UX) results and the status of mineral exploration activities in 2017 (EC
SDW (2018)). The selected UNEXMIN mines are closed or abandoned but can be
reconsidered for future exploitation after further study.
Many of these mines may still contain profitable quantities of raw materials. The main reason
for the closure or the abandonment of the mines was economic: the technology and the
methods used for mineral extraction were too expensive and it was more convenient to
import the necessary raw material from other countries (e.g. Chile, Congo, China, etc.). With
the geological information, the deposit classification and the last owner’s data, the UNEXMIN
database is a potentially important research tool for the initial estimation and identification
of potential sites for future exploitation for the battery industry.
Nowadays, with the development of new mining and refining technologies, mines that were
considered no longer exploitable for economic and technical reasons at the time of closure
can be re-contemplated and re-evaluated in order to reduce the dependency of Europe on
the import of raw materials.
The UNEXMIN submersible robot can be used in the study of potential sites. It is able to
explore and map underground flooded mines and to provide useful data for the mining
industry with its scientific instrumentation. The scientific equipment includes a water
sampler, a conductivity and pH measuring unit, a sub-bottom profiler, a magnetic field
measuring unit, UV fluorescence imaging and multispectral imaging units (Lopes et al.,
2017). It is hoped that the UNEXMIN database and robot will both contribute to expansion
of the battery industry in Europe.
References
EC SWD(2018) 245/2 final. Report on raw materials for battery applications.
COM(2018) 293 final. Annex 2. Strategic action plan on batteries.
COM(2008) 699. The raw materials initiative.
Lopes, L., Zajzon, N., Henley, S., Vörös, C., Martins, A., Almeida, J.M. 2017. UNEXMIN: a new
concept to sustainably obtain geological information from flooded mines. European
Geologist, 44. 54–57.
ISRM. 2008. Mine closure and post mining management: International state of the art.
Technical report. International commission on Mine Closure, International Society of Rock
Mechanics.
Public deliverable UNEXMIN project. 2018. D5.4 Inventory of flooded mines in Europe.
Available at: https://www.unexmin.eu/public-deliverables/#tab-id-5
Science for Environment Policy. 2018. Towards the battery of the future. Future Brief 20.
Brief produced for the European Commission DG Environment by the Science
Communication Unit, UWE, Bristol. Available at: http://ec.europa.eu/science-environment-
policy
[1] Austria did not participate in the UNEXMIN project. Spanish data are under update and
at the time of writing there is no mine that fit the research criteria for the battery industry.
This article has been published in European Geologist Journal 47 – Geology and the energy
transition.
