Tecpetrol has developed a state-of-the-art pilot plant for direct lithium extraction, in collaboration with Techint E&C

Tests are being carried out in the province of Salta in Argentina at 4,100 meters above sea level, to evaluate the effectiveness of an innovative direct lithium extraction technology using brines from different salt flats. The results so far are extremely promising, and the system and processes are being continually fine-tuned, providing data that will be essential when it comes to scaling up the process.

Working closely together with Techint Engineering & Construction, Tecpetrol carried out the project from start to finish, starting with the detailed design of the Direct Lithium Extraction (DLE) pilot plant through to the final execution, commissioning and start-up phases.

The project was a considerable challenge, given its remote location and complex environment, but the company completed it in just seven months. As the first plant of this type to operate in Latin America, the DLE pilot plant is a technological milestone—and it could define the new mainstream design concept for DLE development in the region. “The technology enables the recovery and selective concentration of lithium, and features short cycle times, low water consumption, and effluents that are ready to be reinjected into the salt flats,” explains Nicolás Fiandrino, a Technology Expert from Tecpetrol's Energy Transition Directorate. “This process enhances production efficiency by significantly shortening processing times, and extracts about 90% of the lithium, compared with the evaporative methods used in traditional plants which only extract 30-50%.” 

The lithium obtained in 'El Triángulo', the desert-like area shared by northern Argentina, Chile and Bolivia, is sourced from brine, an aqueous solution pumped up from the subsoil. In the traditional process, the brine is poured into large pools with a surface area of up to 60 km2 or more. The brine is gradually concentrated thanks to natural evaporation processes and then treated to remove other metals, such as sodium and magnesium. The lithium is precipitated as lithium carbonate. As this is quite a lengthy process that can take as long as three years, there is a considerable expectation around DLE, a multi-stage chemical process that replaces natural evaporation. The new technology is a disruptive development with the potential to radically overhaul the lithium extraction process from salt flat brines, the reason behind the construction of the new pilot plant in Salta.

The future of energy

Lithium has a key role to play in the energy storage process; one of its main applications is in the batteries used by mobile phones, computers and electric vehicles (EVs). Currently, the best alternative to decarbonize the passenger transport sector is by using EVs powered by renewable energy, a trend likely to drive lithium demand and price upwards for some time to come.

The ultimate goal of the pilot plant is to scale the innovative DLE technology to an industrial level. Currently, the plant has the capacity to produce 25 t/year of LCE (lithium carbonate equivalent) and can process some 1,000 liters of brine per hour.

"For the Techint Group, this is the driver enabling us to enter the world of lithium in a way that is more productive, efficient and environmentally friendly than other options," explained Fiandrino.

Challenging conditions in a hostile environment

Tecpetrol’s DLE plant lies at 4,100 meters above sea level, and its remote location brings several challenges, including the lack of paved roads and poor general infrastructure. There are also significant temperature and humidity variations, which were taken into account from the start of the project design, as this technology had to be able to prove its worth in a typical site, being viable even in the most hostile terrain and conditions.

Patricio Prandi, Commercial Manager of Techint Engineering & Construction, highlighted that “working at such an altitude was a real challenge, but that’s where the company’s differential comes into play vis-à-vis its peers. We achieved this project in record time, thanks to detailed methodological planning, and it’s a project that enables us to develop new capacities in the lithium segment which is where we want to position ourselves.”

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