The DLE Technologies Competing in the Puna: Adsorption, Ion Exchange and Membranes

What DLE Is and Why It Matters in Argentina

Direct lithium extraction (DLE) groups together a set of technologies that capture the lithium contained in brine through selective physicochemical processes, rather than relying exclusively on solar evaporation in ponds. The traditional method, dominant in the Puna for decades, requires between 12 and 18 months of solar concentration and recoveries that rarely exceed 40-50% of the available lithium. DLE, by contrast, aims for recoveries of 80-90% within hours or days.

Argentina's interest is no coincidence. As the world's fifth-largest lithium producer, with a portfolio of low-cost brines in the Puna regions of Jujuy, Salta and Catamarca, the country faces growing pressure over water use and the environmental footprint of evaporation ponds. DLE promises lower net water consumption, a smaller surface footprint and production less dependent on seasonal climate, albeit at the cost of greater energy and chemical intensity.

Adsorption: The Most Mature Route

Adsorption uses solid materials—typically aluminum, manganese or titanium oxides—that selectively capture lithium ions upon contact with the brine. The lithium is then released into a concentrated eluate by washing with water or dilute solutions. It is the family with the longest commercial track record globally and the one most frequently found in Argentine projects under evaluation, largely because it tolerates brines with relatively high magnesium/lithium ratios, common in the Puna.

Its main challenge is the consumption of fresh water in the elution and washing stages, a sensitive point in a semi-arid region. Several developers are working on schemes to reinject spent brine and reuse water to mitigate that cost. The durability of the adsorbent across thousands of cycles also conditions the economics of the process.

Ion Exchange: Selectivity and Chemical Intensity

Ion exchange uses resins or materials that swap lithium ions for other ions (typically hydrogen) present in the medium. It offers very high selectivity and high-purity eluates, which reduces the downstream purification burden. For that reason it is attractive for brines with complex chemistry, where the presence of impurities heavily penalizes other methods.

The flip side of that selectivity is the demand for reagents: the process usually requires acids and bases to regenerate the materials, generating by-product streams that must be managed and raising operating costs. The logistics of chemical inputs to high-altitude salt flats—above 3,500 meters—adds complexity. Integration with effluent treatment plants is, in these cases, an indispensable part of the design.

Membranes: The Less Mature Promise

Membrane technologies—nanofiltration, selective electrodialysis and hybrid variants—separate lithium by exploiting differences in ionic size or electric charge. In theory they enable continuous, modular processes with lower reagent use. Their appeal lies in the possibility of combining them with other DLE stages to concentrate or purify intermediate streams.

However, this is the least proven family at industrial scale in lithium brines. Membrane fouling, sensitivity to variable brine composition and the cost of replacing modules are obstacles that still limit their mass deployment. In the Puna, their most likely role, at least in the short term, is complementary rather than central.

The Real Test: Scaling from Pilot Plant to Commercial Operation

The DLE bottleneck lies not in the laboratory but in the scale-up. Promising pilot yields do not always hold when volumes increase, brine chemistry varies seasonally and thousands of cycles accumulate on the active material. Water management, disposal of spent brine and the availability of firm energy at remote high-altitude sites are as decisive as the technology itself.

Added to this is an environmental unknown: the reinjection of treated brine into the aquifer, proposed as a solution to the water balance, still requires long-term hydrogeological validation in each basin. No DLE technology is universal; its performance depends intimately on the particular composition of each salt flat.

Argentina Facing the Technology Decision

The Puna concentrates a diversity of brines that makes a single technological winner unlikely. It is more realistic to anticipate a map of tailored solutions, where adsorption leads the first commercial deployments, ion exchange addresses chemically demanding brines, and membranes are integrated as refining stages. The RIGI framework, in force since 2024, improves predictability for capital-intensive investments such as those DLE demands.

For Argentina, the strategic challenge is not merely to adopt DLE, but to do so by developing local technical capacity, robust environmental criteria and validation under real high-altitude conditions. The technology that prevails will be the one that demonstrates, in each basin, consistent recoveries, a defensible water balance and competitive costs throughout the entire life of the project.