Extraction of concentrates, waste cathode material, ore and tailings

Using alkaline leaching process on spodumene concentrate, the maximum extraction of Li achieved thus far reached 75%. The leachate transformation, even after the filtration step, hinders the sample analysis and further processing. To overcome this challenge, upcoming experiments will explore  elevated temperatures, diverse additives, and further investigate the chemical precipitation process.

During the advanced solvometallurgy applied on spodumene concentrate, the research team at TECNALIA reported high Li leaching yields (>95%). Their future work will focus on the further optimisation of the operational conditions, more appropriate for the anticipated scalability phases of the process. On the other hand, solvometallurgical tests carried on waste cathode material achieved high leaching yields for all target elements (Li, Co, Ni, Mn) using mild operational parameters.

After the first experiments engaging reactive milling and aqueous leaching [treated with aluminium- (Al) and calcium (Ca) – salts] on waste cathode material, researchers at KIT reported close to 31% Li recovery rate. Samples supplied by UMICORE were leached under different conditions to extract Li – available in the form of Li carbonate [LiCO3], and further subjected to purifications processes employing various reducing agents. Future efforts for this particular task will focus on adjusting leaching temperatures, establishing an optimal purification process, and evaluating Li recoverability in both Al and Ca systems.

Separation and purification of Li from solutions

Anticipating future upscaling phases, researchers at VITO, working on the Li-sieve adsorption and desorption from aqueous leachates, shaped the lithium-titanium-oxide (LTO) adsorbents into spheres, which enabled dynamic testing. The team is currently optimising the flow rates for adsorption and desorption to model the optimal conditions for upcoming processes. While initial tests utilised synthetic Li solutions, upcoming research will extend to purification processes for spodumene leachates.

In the same work package, TECNALIA performed experiments using different organic solvents for the liquid/liquid (L/L) extraction from brines showing promising Li yields in the range of 40-60%.

Within the same work package, EnBW scientific team has been working on designing an eco-friendly Li-desorption process from brines, focusing on the development of novel synthesis for Mn-based adsorbent material. Notably, the successful upscaling of the synthesis process from 2,5g to 200g marks a significant achievement in sustainable material synthesis.

Finally, the last task of WP5 – Electrode-based Li adsorption and desorption from brines, conducted by KIT, presented the conclusions of their research work carried during the last six months, which includes a 4-step process. Their work has been focusing recently on the optimisation of the electrode pre-treatment, the establishment of the current densities and the reduction of the Na contaminations. Despite high Li selectivity rates obtained thus far, their work in the upcoming months will centre around optimising the recovery efficiency and the selectivity. Future experiments will test different thermal operating conditions (40°, 60°, 80°), but will also attempt to scale-up the process.

Recovery as battery-grade chemicals

In the final technical work package, SINTEF scientists are pioneering a two-step process which involves in a primary phase selective chlorination by converting insoluble oxides to soluble chlorides; this is followed by a second step – electrolysis of the soluble chlorides extracting the target elements. After conducting different chlorination experiments, researchers emphasised the importance of time and the processing duration, confirming over 65% Li recovery rate. With promising results, their focus pivots towards the second step – electrolysis.

Read the next article for a comprehensive overview of the meeting.

Marking the project’s first anniversary, the LiCORNE partners gathered in sunny city of Athens to draw the line and brief on the progress achieved thus far. The meeting was hosted by the National Technical University of Athens (NTUA) and it unfolded over two days, including also a visit of the NTUA mineralogical museum and its metallurgy laboratory facilities.

Press the “play” button below to watch snippets of the 1-year consortium meeting and interviews with various partners

Supply and characterisation of feedstock

Starting with work package (WP) 2, partners from EnBW presented the characteristics of the Bruchsal geothermal reservoir, located at the eastern edge of Upper Rhine Valley. EnBW highlighted that geothermal brines in the Upper Rhine Valley are recognised for their relatively high lithium (Li) concentrations. Additionally, the region displays an extension structure striking in the NNE-SSW direction, with a length of around 300 km and a width of up to 40 km. In this area, the deep geothermal fluids utilised for geothermal applications exhibit a maximum Li concentration ranging from 163 to 190 mg/L (Sanjuan et al., 2016). The highest Li concentration was detected in the hydrothermal alteration zone of Lower Buntsandstein.

In the forthcoming months, new samples are prepared for delivery to research partners: geothermal and continental brines, but also Li-phosphate samples, a new Li-mica concentrate and synthetic brine solutions. Upcoming research will mainly focus on the geochemical analysis of rock samples from the reservoirs.

Beneficiation and physico-chemical transformation of concentrates

In the mining industry or extractive metallurgy, beneficiation is any process which removes the gangue minerals from ore to produce a higher-grade product, and a waste stream – which, despite the lack of valuable materials, needs to be sustainably treated. In charge of the beneficiation step, TU Delft already presented in M12 videos of the operational opto-magnetically-induced sorting lab setup to process crushed spodumene ore. This proof of concept aims to separate the Li-rich fractions of the ore before reaching the metallurgical processes. This preliminary step helps improve efficiencies and decrease cost in processes downstream.

Researchers at NTUA, working on the development of a calcination technology working at lower temperatures, presented the first results of their investigations using various additive combinations and leaching experiments studying the effect of temperature, time and leaching agents. Tests showed that the use of additives has the potential to maintain the calcination operating temperature of spodumene at low temperatures compared to conventional routes. Moreover, researchers achieved over 92% Li extraction during various leaching experiments conducted so far. Recognising the environmental footprint associated with the conventional routes used for Li extraction, NTUA research team will continue experimenting with new additives in order to develop a new technology that is more environmentally sustainable and equally more competitive.

Working with spodumene samples, TECNALIA researchers have been working on the ball milling-assisted chemical transformation, testing the use of various additives and experimenting with different thermal treatments. Their upcoming work will focus on optimising the ball milling process to obtain materials with similar leaching properties but being produced with less intense thermal processes.

Read the next article for a complete overview of all the work packages.

VITO achieves direct lithium extraction, using the Gas-Diffusion Electrocrystallisation (GDEx) technology. GDEx uses gas-diffusion electrodes to achieve this goal, by producing in-situ the necessary quantities of mild chemicals, which in turn form precipitates containing lithium.  

During this period, the GDEx team has conducted experiments with synthetic solutions. The effect of adding chemical supplements to the process is being investigated to optimise the lithium recovery yield and selectivity vs. competing ions in solution. After optimising the GDEx process with synthetic streams and learning about the precipitating mechanisms, we are looking forward to extending the process in various geothermal brine solutions obtained from the consortium partners. After precipitation in the form of layered-double hydroxides, the GDEx team will investigate the downstream steps to obtain battery-grade lithium hydroxide. 

More information about the GDEx process can be found at