[Publi’ Story] Lithium triangle and energy transition:
new leads to evaluate brine-type deposits across the Andean plateau
The world-renowned brine deposits located in the Lithium Triangle (Li) hold huge reserves. In the Central Andes, lithium in its ionic form (Li+) is found dissolved in the brines present in a number of salt deserts (salares and salinas) formed in endoreic basins that are located at more than 3,000 meters above sea level.
Nowadays, Li is an essential element for the energy transition: it is used in the manufacture of batteries for electronic equipment and electric vehicles. In the Andean plateau, the exploration for Li deposits began almost a century ago. Subsequently, the largest deposits in the world, including those in the Atacama salt pans in Chile, Uyuni in Bolivia, Hombre Muerto and Olaroz in Argentina, were discovered and exploited. During the last decades, several estimates have been put forward indicating that the Lithium Triangle would hold nearly 2/3 of the world’s resources. However, to this day the Li concentration of a good part of the salars of this Andean region is only poorly known and their data often fragmentary.
Location of the Lithium Triangle in the Andean plateau, and a view of an artisanal exploitation at Salinas Grandes, Argentinian Andes.
To overcome this, the GET french team and the IDEVEA argentinian team have established the first comprehensive compilation of Li concentrations in brine-type deposits at the scale of the Andean plateau. The study, published in Earth Science Reviews, synthesizes hydrochemical data reported by previous scientific studies conducted in 49 Andean salars across the region.
The results of the study provide, for the first time, a global view of brine-type deposits in the Lithium Triangle. We have shown the existence of a pattern linking the surface of the salars to that of the endoreic basins, with linear proportionalities ranging from 1:5 to 1:10. In addition, a proportionality of 2:1 is evidenced between the maximum and average values of Li concentrations. The latter finding implies that the average Li concentrations in brines from a salar can be estimated from the maximum measured concentration (average Li concentration ≈ ½ of the maximum Li concentration). This relationship provides an initial indicative value and is of use especially in early instances of exploration of this type of resource, when the number of samples is still insufficient for calculation of a representative average.
Whilst the hydrochemistry of the 477 brine samples considered in the study exhibits some degree of compositional consistency and spatial organization, the data show no geographical trend in the distribution of Li concentrations across the plateau. The distribution of lithium therefore remains a key scientific question in understanding the formation processes of brine-type Li deposits. In this sense, the study provides a new lead: Li concentrations can be related to the surfaces of salars and watersheds. It would therefore be not only the largest salars, but also the oldest that would contain the highest concentrations of Li.
🗞️ Find out more
Lopez Steinmetz R.L. & Salvi, S. (2021). Brine grades in Andean salars: when basin size matters. A review of the Lithium Triangle. Earth Science Reviews. DOI | https://doi.org/10.1016/j.earscirev.2021.103615
Romina López Steinmetz – IDEVEA (CONICET – UTN), San Rafael, Mendoza, Argentina.
+33 6 40 78 96 82
Stefano Salvi – GET – Géosciences Environnement Toulouse (Université Toulouse III, UMR 5563 CNRS, IRD, CNES)
+33 5 61 33 25 83