On the 19th local time, in Salta province, Argentina, on the exact opposite side of Korea. After a 35-minute flight in a light aircraft to the Andes plateau at 4,000 meters above sea level, an emerald pond (an artificial evaporation pond) sparkled like an oasis in the middle of Mars-like tawny ground. It is a vast "lithium salt field" that concentrates lithium brine pumped from underground by the sun and wind.
Beyond the pond stood a factory, an LNG power plant, and about 400 utility poles in a row. After only a few steps, breathing turned labored and the head felt foggy. It was a sign of oxygen shortage. In this windswept highland, about 320 POSCO Argentina employees take turns every one to two weeks to build a "lithium production base." POSCO Holdings is the first among domestic corporations to produce lithium directly from an overseas salt lake.
One resident officer who has been stationed here for four years said, "Just as a steel mill was built on the sandy fields of Pohang in the 1970s, we are creating something out of nothing in a highland with a different language and culture." The officer noted, "With oxygen at only 60% of that at sea level, sleeping is still hard, but with a sense of duty that if we don't do it, who will, we completed Plant 1 and are accelerating the production test for Plant 2."
At first there was no water or electricity to run the plant, so they drew fresh water through pipelines from 34 kilometers away and built their own power station. Equipment was trucked up the mountains for seven hours, and lodging, dining, and medical facilities were built together.
◇ Lithium 15 million tons in a mining right half the size of Seoul… concentrated for 4 months into battery feedstock
This treeless place is the Hombre Muerto salt lake area, called "dead man" in Spanish. It looks like a barren wasteland, but underground is lithium, known as "white oil," dissolved in brine.
POSCO Holdings acquired this salt lake mining right in succession in 2018 and again this year, securing a total of 287 square kilometers. About half the size of the city of Seoul, the underground brine is estimated to contain 15 million tons of lithium—enough to make batteries for about 70 million electric vehicles. The so-called "golden salt" project has invested about $2.3 billion (about 3.17 trillion won) so far. It is a bold move to secure raw materials directly in a lithium supply chain heavily dependent on China.
The reason they planted a flag in such a remote place is lithium concentration. The brine here contains an average of 921 milligrams of lithium per liter (ℓ). It is the second-highest in the world after the Atacama salt lake in Chile. To produce the same amount of lithium, the higher the concentration, the less brine needs to be pumped, evaporated, and refined. Concentration is effectively the cost.
In fact, raw materials account for less than 1% of POSCO Argentina's manufacturing cost. With more than 43% of the world's lithium clustered along the border of Argentina, Chile, and Bolivia, Chinese companies are also speeding up to secure mining rights in the area.
Even after securing a salt lake with high lithium concentration, the path to commercial production was a series of challenges and trial and error. The brine contains salts about eight times that of seawater, while lithium is less than 1 gram per liter. Dipping a fingertip into the pond and tasting it left the tongue stinging with saltiness.
Lithium production starts by finding and extracting brine with high concentration from this "salt-laden" mixture. Geological surveys identify high-concentration spots, wells are drilled down to 450 meters, and brine is pumped up. It is spread shallowly to a height of 30 centimeters across pond sections partitioned like paddy ridges. As the brine passes through multiple sections over four months and water evaporates, the lithium concentration becomes nearly five times higher.
Winter was another hurdle. In winter, daily evaporation drops to half that of summer, and on days when winds exceed 100 kilometers per hour, operations stop altogether. To prepare for slower winter concentration, they were adding a fourth standby line alongside the existing three production lines.
Lee Se-jin, chief financial officer (CFO) of POSCO Argentina, said, "This is a business that must comply with nature," and added, "We designed the ponds with even a once-in-10-years flood in mind, but when unexpected rain falls, the brine gets diluted, and just looking at the sky makes one uneasy."
POSCO Holdings applies a proprietary process to the concentrated brine. As impurities are removed one by one, lithium is also lost. So they add phosphoric acid to selectively pull out only lithium, first producing a fine white powder of lithium phosphate like flour.
This powder is loaded onto trucks and taken down about eight hours to the Gueymés downstream process at around 1,200 meters above sea level, where it is redissolved and, after high-purity refining and bipolar electrodialysis (BPED), becomes lithium hydroxide used in high-performance electric-vehicle batteries.
By tailoring and connecting these processes into one to match the local brine characteristics and optimizing Production yield, the production period that took more than a year during development has been cut to one-third. Park Hyun, head of POSCO Argentina, said, "This process was the only one of its kind in the world when commercialized, and now Chinese companies are following it." At the shipping area of the Gueymés plant, which runs 24 hours a day, lithium hydroxide vacuum-packed in 450-kilogram units was stacked neatly. It will be moved to Buenos Aires and shipped by sea to Korea and Europe.
◇ First profit in 8 years, next target is 100,000 tons of lithium a year
After eight years of struggle, POSCO Argentina posted its first quarterly operating profit in the second quarter, with 11 billion won in the black. Output rose, and the price of lithium hydroxide, which had fallen to the $8,000-per-ton range in Jul. last year, has recently rebounded to around $18,000.
The price plunge at the time directly affected the business's profitability enough to slow follow-up investment. Park said, "Global institutions expect lithium prices to stay in the $15,000–$20,000 per ton range going forward," adding, "Unlike companies that buy concentrate, we have secured brine resources directly, so at that price level we do not see much to worry about." POSCO Holdings forecast that if $20,000 per ton is maintained, the operating margin in 2028 will be 41%, and at $15,000 it will be 22%.
As production increases, sales channels are also widening. Starting this year, POSCO Argentina will supply up to 25,000 tons of lithium over three years to SK On. Of this year's 17,000-ton output, more than half already has buyers. The next goal is an annual 100,000-ton production system in Argentina. Plants 1 and 2 will each produce 25,000 tons a year of lithium hydroxide for high-end ternary (NCM) batteries for electric vehicles, and Plants 3 and 4, to be completed in 2030 and 2033, will each add 25,000 tons of lithium carbonate.
With lithium carbonate, the strategy is to capture demand for ESS (energy storage systems) used in AI (artificial intelligence) data centers and LFP (lithium iron phosphate) batteries for mid- to low-priced electric vehicles. Lithium from Argentina will be sold directly to customers or used as cathode material feedstock at POSCO FUTURE M to build a proprietary supply chain from raw materials to materials.
To steadily produce 100,000 tons of lithium every year, it is also essential to root the production system locally. Of POSCO Argentina's 623 officers and employees, only 63 are Korean resident officers. Working with 560 local employees, the resident officers are developing managers and engineers and opening an in-house tech center to teach on-site skills such as welding, piping, and electricity.
Facundo Valderrama, a local employee met in the highlands, said, "Thanks to POSCO's lithium business, people from neighborhoods like mine have gotten jobs, and as surrounding corporations supplying parts grow, the whole town is coming back to life," adding, "Working with colleagues from Korea, I enjoy and appreciate learning new technologies and culture."