Lithium producers zero in on technology for direct extraction

Companies developing technologies to chemically extract lithium directly from brine promise to obtain the battery raw material in a way that has less environmental impact than the large evaporation ponds commonly used today. After an explosion of investment into multiple direct extraction approaches, adsorbent resins are emerging as the winner in the race to reshape lithium production.

In May, US Magnesium picked adsorbent-based direct lithium extraction (DLE) technology from International Battery Metals for its lithium project in Utah. And CleanTech Lithium successfully started up a pilot plant in Chile to test an adsorbent-based DLE technology.

Additional firms are switching to adsorbents from other options. In April, Standard Lithium installed an adsorption column from Koch Technology Solutions at a demonstration plant in Arkansas; it plans to use this technology rather than its own ion-exchange process at a commercial-scale facility. That follows decisions by Anson Resources and Controlled Thermal Resources in 2022 to use adsorption technologies over ion exchange.

Big lithium companies like Albemarle and SQM have traditionally used evaporation ponds to concentrate lithium-rich brines before chemically converting the metal into the raw materials for lithium-ion batteries. DLE firms argue that their processes have a smaller environmental footprint and will allow customers to exploit brines with lower concentrations of lithium.

Adsorbent resins were the first DLE technology to be commercialized. Arcadium Lithium’s facility in Argentina started using them in combination with evaporation ponds in 1996.

But in the following decades DLE was deployed by just a handful of other companies, in China. Only recently did a spike in lithium prices and growing demand from the battery industry spur renewed interest in the technology.

Investment in DLE companies jumped from 25 deals worth $90 million in 2020 to 46 deals worth more than $1 billion in 2023, according to the research firm Pitchbook. This investment was spread across several technologies, including adsorbents, solvent extraction, and ion-exchange materials.

For a time, ion-exchange backers like Standard Lithium, E3 Lithium, and Lilac Solutions seemed to be pulling ahead of proponents of adsorbent materials. In an adsorption process, lithium salts from brine bind to the surface of a resin and are then washed off with water. In contrast, ion-exchange materials selectively bind to lithium at a certain pH, so the process usually requires an acid.

Andy Robinson, Standard Lithium’s chief operating officer, says both technologies efficiently remove lithium from brine. The company switched to adsorbents to avoid having to buy acid. “Chemical pricing, post-COVID, was high and remains stubbornly high,” he says. “An adsorbent process . . . removed a lot of that commodity chemical reagent consumption.”

In February, E3 Lithium announced that it would use an unnamed, third-party technology rather than its own ion-exchange process for its first commercial plant.

After several years of testing, Cameron Perks, principal lithium analyst with Benchmark Mineral Intelligence, says some companies are discovering that their own processes aren’t any better than the adsorption technologies available commercially. “Adsorption is the front-runner. Everyone knows it. It’s the technology that everyone is familiar with,” he says. “It’s got a long head start.”

In many cases, the adsorbent resins that DLE companies plan to use come from just a few Chinese firms. Sunresin is supplying resins to DLE projects in China, Argentina, and the US. In October 2023, Koch announced that it would source adsorbent materials from Xi’an Lanshen New Material Technology, as will CleanTech Lithium. Lithium Energy will also use Xi’an Lanshen adsorbents at a project in Argentina.

Garrett Krall, director of strategic initiatives at Koch Technology Solutions, says the adsorbent used in a DLE process is not all that determines its success. Koch seeks to differentiate itself from competitors by using its filtration expertise to maximize the performance of Xi’an Lanshen’s adsorbents. “You’ve got to focus on the front end to set the adsorbent up for success,” Krall says.

In addition to signing the agreement with Standard Lithium, Koch is shopping its DLE process around projects in North and South America.

Some of the biggest decisions about DLE still loom. Albemarle and SQM are testing technologies in Chile. Last year, Exxon announced that it was drilling a lithium well in Arkansas but didn’t disclose which DLE process it will use.

While adsorbent processes are notching successes, other approaches continue to advance. Lake Resources wants to open a DLE plant in Argentina based on Lilac’s ion-exchange technology, and E3 says it is evaluating its own ion-exchange process for future plants.

SQM’s venture arm has invested in Adionics, which is developing a solvent extraction DLE method, and in Salinity Solutions, which hopes to use membranes as part of a DLE process.

Benchmark’s Perks says lithium producers will keep looking for the technology that performs best in their particular brine and won’t hesitate to switch if they find something better. “All these players are cross-checking and testing everybody’s technologies, in hopes that they might find the perfect one,” he says. “Every brine is somewhat different.”