The world contains vast quantities of lithium, an integral element in electric vehicle batteries. And though lithium is commonly mined from hard rock, the majority of the world’s lithium reserves are actually found in brine, extremely salty water beneath the Earth’s surface.
Today, brine mining involves evaporating the brine in massive, extravagantly colored pools over a series of about 18 months, leaving high concentrations of lithium behind. It’s a simple but inefficient process that takes up vast swaths of land and is ecologically disruptive.
As automakers around the world struggle to meet extraordinarily ambitious electric vehicle production targets, there’s growing interest in doing things differently.
“The auto industry requires a 20x increase in lithium supply, and there’s just no way to achieve that type of growth with conventional technologies,” said Dave Snydacker, founder and CEO of Lilac Solutions.
Lilac is one of a number of companies piloting a set of new and largely unproven technologies called direct lithium extraction, or DLE, which could increase the efficiency and decrease the negative externalities of the brine mining process.
Instead of concentrating lithium by evaporating brine in large pools, DLE pulls the brine directly into a processing unit, puts it through a series of chemical processes to separate the lithium, then injects it back underground. This process produces battery-grade lithium carbonate or hydroxide in a matter of hours, without the need to transport concentrated brine to a separate processing facility.
DLE could also help jump-start the domestic lithium mining market. Today, most lithium brine mining takes place in the Salar de Atacama, an expansive salt flat in northern Chile that contains the highest quality lithium brine in the world. But DLE technologies require much less land and can help unlock resources in areas where the brine contains less lithium and more impurities.
North American companies Lilac Solutions, EnergyX and Standard Lithium are exploring lithium resources in areas such as Arkansas’ Smackover Formation, California’s Salton Sea and Utah’s Great Salt Lake, as well as abroad in Argentina, Bolivia and Chile. The Chilean government has even announced that all new lithium projects will be required to use DLE technology.
“So the timing is right and ripe for this to see the light of day very, very soon,” said Amit Patwardhan, CTO of EnergyX.
Doing things differently
In a world before electric vehicles, traditional methods of brine mining and hard rock mining more than sufficed to meet global lithium demand.
“The world didn’t need DLE for the last 50 years. Lithium’s primary use was industrial — ceramics, glass and lubricants,” said Robert Mintak, CEO of Standard Lithium.
But with demand for EVs and the lithium-ion batteries that power them booming, now there’s a supply crunch.
“Over the last 10 years, 90% of new lithium production has come from hard rock projects. But hard rock projects are increasingly expensive as we go into lower grade resources. And if you add up all the hard rock projects, there’s just not enough resource out there to meet automaker goals. It’s the brine resources that are large enough to electrify the vehicle industry,” Snydacker said.
DLE is already being used to some extent in both Argentina and China, where the companies Livent and Sunresin are implementing commercial tech that combines DLE with traditional evaporation pond operations.
These companies both rely on a technology called adsorption, the only commercially proven approach to DLE. In this process, lithium molecules in the brine adhere to an adsorbant substance, removing them from surrounding impurities. But experts say that stripping the lithium from the adsorbents requires a lot of fresh water, a big problem considering many of the world’s best brine resources are in arid areas.
Livent’s most recent sustainability report indicates that it uses 71.4 metric tons of fresh water per metric ton of lithium carbonate equivalent, or LCE, produced. Lilac reported that in pilot testing it uses between 10 and 20 metric tons of fresh water, while EnergyX says it uses less than 20 metric tons.
China-based Sunresin says that it recycles all of its fresh water, and that its newer projects will operate without evaporation ponds.
But a host of other companies are now getting into the industry, testing out alternative technologies which they claim will not only eliminate evaporation ponds altogether, but increase yields while lowering energy and fresh water requirements.
Bay Area-based Lilac Solutions is using a technology called ion exchange. It’s currently piloting its tech in Argentina in partnership with Australian lithium company Lake Resources.
“With the Lilac ion-exchange bead we’ve developed a ceramic material. This ceramic selectively absorbs lithium from the brine while releasing a proton. Once the lithium is absorbed into the material, we then flush the lithium out of the bead using dilute acid and that produces a lithium chloride concentrate which can be easily processed into battery grade chemicals,” Snydacker explained.
Lilac expects to have its first commercial-scale module operating before the end of 2024. The company is backed by BMW and the Bill Gates-funded Breakthrough Energy Ventures, and Ford has signed a nonbinding agreement to buy lithium from its Argentina plant.
EnergyX, which is based out of both San Juan, Puerto Rico, and Austin, Texas, uses a combination of technologies that it can tailor to the specific brine resource. Step one is traditional adsorption, followed by a method known as “solvent extraction,” in which the concentrated brine is mixed with an organic liquid. The lithium is then transferred to the organic before it’s stripped free and concentrated. Membrane filtration is the final stage, which removes all remaining impurities.
“So you see these all these loops and synergies that come out of combining these technologies. And that is another big differentiator in what EnergyX does and what really drives the cost of the technology much lower compared to anybody else,” said Patwardhan.
EnergyX is building demonstration plants with undisclosed partners in Argentina, Arkansas, Chile, California and Utah, and is aiming to have the first two up and running by the end of this year. Recently, the company secured $50 million in funding from GM to help scale its tech.
Vancouver-based Standard Lithium also has big backers. The public company’s largest investor is Koch Industries, and it’s been running a demonstration plant in South Arkansas for the last three years, producing lithium at a preexisting bromine plant.
The company uses both ion-exchange and adsorption technologies, depending on the resource. It expects to begin construction on a commercial-scale DLE facility next year and is expanding into Texas as well.
“We have an opportunity as we expand from Arkansas to Texas to be the largest producing area for lithium chemicals in North America, utilizing in an area that’s not under water stress, that has a social license to operate,” said Mintak.
Companies such as Standard Lithium, which are leaning into the U.S. market, stand to benefit from the Inflation Reduction Act, which ties electric vehicle subsidies to domestic sourcing of battery materials. Automakers can also receive the full EV credit if they source from countries that have free trade agreements with the U.S., such as Chile.
While Chile has announced that all new lithium projects in the country will be required to use DLE technologies, it has not announced what companies it will be partnering with for these new projects.
Neighboring Bolivia is also looking to utilize direct lithium extraction to help unlock the country’s vast, but largely undeveloped, lithium resources. The government has tapped a consortium of Chinese companies, led by battery giant CATL, to spearhead DLE efforts in its salt flats, and is considering a future partnership with Lilac as well.
Most new lithium supply will continue to come from hard rock projects for the rest of this decade, Snydacker said. “But by the end of this decade, we’ll see very large-scale brine projects coming online …” he predicted. “And going out into the next decade, this technology will provide a majority of new supply.”
Overall, lithium production from DLE is projected to grow from about 54,000 metric tons today to 647,500 metric tons by 2032, according to Benchmark Mineral Intelligence. That’s forecast to be worth about $21.6 billion.
“But when we place it in relative terms against the rest of the global market, that only represents around 15% of total supply,” said James Mills, principal consultant at Benchmark Mineral Intelligence. “So we’re still going to have to rely on traditional forms of production for the lithium units, whether it’s evaporation ponds or hard rock mining.”