The Rotliegend as a Lithium Resource in the North German Basin – From Exploration to Extraction | RoLiXX
Although high concentrations of the critical raw material lithium (Li)—ranging from 100 to 600 mg/L—have been detected in deep formation waters within the Rotliegend sandstones of the North German Basin (NDB), questions remain regarding the origin and genesis of this enrichment, as well as the extraction of the resource. Within the framework of the RoLiXX project and the specific GFZ sub-project, the aim is firstly (1) to investigate the precise source of the lithium and the conditions under which this enrichment occurred, thereby enabling predictions regarding favorable sites for lithium extraction. To this end, a range of geochemical methods (including isotope geochemistry) will be applied to various rock and fluid samples collected across the NDB; this will allow for a large-scale understanding of the geological processes and the development of a conceptual model for the genesis of lithium deposits in sedimentary brines.
Secondly (2), methods will be developed to enable lithium extraction from these complex, highly saline fluids without causing massive, toxic precipitation—a process referred to as "solids-free production." Such precipitation poses one of the greatest challenges to extracting lithium from these brines. The sub-project involves testing various strategies to prevent both electrochemically induced scaling and the precipitation of sparingly soluble salts; initial testing will take place at the laboratory scale, with the most successful methods subsequently applied in the field. This upscaling (3) will extend to the "mini-plant" level, involving flow-through experiments using actual deep formation water. The work within this sub-project spans all three areas, thereby bridging the activities of the various consortium partners.
The results can be utilized for lithium exploration and economically viable lithium extraction, as well as for ecological assessments. In addition, this enables the further development of the co-utilization of heat from Rotliegend thermal waters (deep geothermal energy), which contributes not only to resource sovereignty but also to achieving climate neutrality in Germany and Europe.
Lithium (Li) is a strategic raw material for the energy transition, particularly for lithium-ion batteries. Due to rapidly rising demand, the European Union classifies lithium as a critical raw material and anticipates a twelvefold increase in demand by 2030. However, Europe currently relies heavily on imports. The Rotliegend sandstones of the North German Basin (NDB) contain exceptionally lithium-rich deep formation waters; while these represent one of Europe's largest potential lithium resources, they have remained largely unexploited to date due to great depths, geological uncertainties, and technical challenges associated with lithium extraction.
The joint research project RoLiXX therefore pursues three objectives: (1) identifying the geological sources and mobilization mechanisms of lithium; (2) predicting lithium-rich zones within the NDB using models based on deposit genesis and stratigraphy; and (3) developing efficient, environmentally friendly extraction processes that avoid the problematic precipitation of radioactive or toxic substances.
The GFZ sub-project investigates the origin, bonding forms, and mobilization of lithium within Rotliegend rocks and adjacent strata. To this end, drill cores undergo geochemical analysis and thermal waters undergo isotope-geochemical analysis to better understand how lithium is released into the deep formation waters.
Another key focus is the development of a solids-free method for extracting lithium from the thermal waters. This involves testing corrosion-resistant materials and additives designed to prevent corrosion and barite precipitation, as well as evaluating their compatibility with one another. Finally, the results will be validated in a mini-plant under realistic operating conditions and assessed through fluid-geochemical monitoring.
The data obtained will enable the prediction of lithium-rich reservoir zones and support the development of suitable production and extraction strategies. The project thus makes a significant contribution to unlocking a strategic lithium resource and strengthening European value chains for energy technologies.