A guide to DLE, the technology that could transform lithium mining

Brine lithium mining is at a crossroads.

Traditionally, it’s used evaporation ponds which can take months or years to produce the battery metal. Now, more and more brine projects are trying a group of technologies called direct lithium extraction (DLE). Advocates say it could slash production times to hours and days, improve recovery and reduce environmental impacts compared to the ponds that can be 60 sq. km.  

Companies in testing say they’re already outperforming Goldman Sachs estimates this year of DLE recovery rates of at least 80% vs evaporation ponds at around 50%. And they’re beating the bank’s rough DLE operating cost guide of US$5,700 per tonne of lithium carbonate equivalent (LCE). It’s selling this week for US$22,675 a tonne, according to Dow Jones. 

Even if less than half of Latin America’s brine projects adopt the technology, annual LCE output will increase by as much as 140,000 tonnes, the bank said. That’s 19% of last year’s global production, according to world leader Australia. 

There are three main DLE types:

Adsorption: A brine flows across a material such as clay, silicate or carbon known as an adsorbent. Lithium adheres to cavities on the surface and is collected by washing the adsorbent with water and diluted lithium chloride. 

Ion exchange: Works like a water softener to extract the ions of lithium out of the brine. The brine flows through material, often a polymer resin in the form of small round beads, that acts as a filter. It is washed with acid, often hydrochloric, to collect the lithium, then neutralized with a base such as sodium hydroxide. The downside includes the environmental risk and cost of using acid and base. Also, the resin must be made to suit each brine’s chemistry, which is different.

Solvent extraction: This process involves using a solvent such as kerosene to capture lithium from the brine. Despite the appeal of its high recovery rates, few projects use this method and most DLE proponents see little future in it at least partly because of its environmental impact.

Three companies

International Battery Metals (CSE: IBAT; US-OTC: IBATF), a lithium extraction technology company based in Houston, has developed its own method which it calls absorption and adsorption. John Burba, considered the father of DLE, developed the process after decades in the business. He designed the initial adsorption plant for Livent’s (NYSE: LTHM) Hombre Muerto project in Argentina, which expects first LCE this quarter and commercial amounts by year’s end.

“This process, it’s not the same but it’s very similar to the Livent process. We’ve simplified it dramatically in this particular situation,” Burba, IBAT executive chairman and director of global technology, said by phone. “We are getting remarkably sharp separations between the brine and the water.”

The company wants to start using the technology on a project this year in the United States or South America, but the site hasn’t been selected. Joshua Hebert, vice-president of field operations, says the company is dealing with a range of clients, all with non-disclosure agreements so he can’t say who they are.

“We currently have the only working commercial DLE mobile modular extraction plant in the world,” Hebert said. “We’ve gone through some optimizations and you know, put all the bells and whistles that we wanted to on it to get it ready for the big show.”

Combination method

IBAT’s method sees the lithium in brine absorbed into a crystalline structure that excludes other elements by size, Burba said. It uses water to wash the lithium out of the structure and doesn’t require acid or base. IBAT claims it is stronger and more efficient than others on the market, boasting extraction rates from the brine at about 99%, and total recovery rates ranging from 92-98%.

Operating costs would be US$1,500 to US$2,000 a tonne of LCE output depending on fuel prices to extract from a brine holding 600 parts per million lithium, Burba said. It would produce a 35% lithium chloride solution suitable to make LCE.

A typical 20,000-tonne-a-year lithium project using IBAT technology could be up and running 18 months after delivery for a cost of about US$250-300 million, Burba said. That compares with six year’s construction time for a traditional plant costing about US$600 million like Livent first envisioned in Argentina.

CleanTech Lithium (AIM: CTL), which has three projects in northern Chile, favours adsorption across resins. The method has been used in the industry for some two decades, Jason Baverstock, co-founder and business development manager, said by phone.

“The technology is a winner because it’s commercially proven,” Baverstock said. “For us, low-salinity water is used to de-sorp the lithium ions from the resin, whereas with ion exchange they use usually hydrochloric acid or an acid base material for the de-sorp.”

CleanTech uses resins by Sunresin based in Shaanxi, about 1,100 km southwest of Beijing. Sunresin makes about 50,000 cubic metres of ion exchange resins and adsorbers annually.

Jersey, United Kingdom-based CleanTech is preparing a prefeasibility study on the Laguna Verde project due early next year after completing a scoping study this year. It estimated an operating cost of US$3,875 per tonne.

At its Francisco Basin project, the company released a scoping study in September and is drilling until about June to expand and upgrade its resource. It may start a prefeasibility study on that project late next year.

Both projects, which are about 950 km north of Santiago, the capital, aim to produce 20,000 tonnes annually of battery-grade LCE. Laguna Verde would start in 2026, Francisco Basin a year later. A third project, the early-stage Llamara, is about 600 km north of the others.

E3 Lithium (TSXV: ETL; US-OTC: EEMMF), with Canada’s largest resource of the light metal, is still deciding which DLE technology it wants to adopt for its Clearwater project in Alberta. It’s forecast to start in mid-to-late 2026.

Science experiment

The company is testing three systems, including its own, that are ion exchange or adsorption, CEO Chris Doornbos said by phone. They’re all looking strong, but the winner will likely be the one that can go quickest to market, he said. That isn’t E3’s own technology simply because it hasn’t had enough time and money to develop it.

“We’re really pushing hard not to be a science experiment anymore and to build a commercial facility,” he said. “There are third party systems out there that are further advanced.”

E3 will select which technology to pursue within weeks because it will form the basis of its Clearwater prefeasibility study that’s due early next year, he said. See him discuss the project in a video interview.

The project, which plans to tap brine for green energy lithium from the same Leduc crude oil aquifer that boosted the province’s post-war petroleum industry, has an after-tax net present value of $820 million at an 8% discount rate with an internal rate of return of 27%, according to a 2020 preliminary economic assessment.

The aquifer holds 16 million tonnes of LCE in the measured and indicated categories and 900,000 inferred tonnes of LCE. 

Most projects intend to inject the post-lithium brine back underground. Doornbos said DLE technologies have comparable environmental profiles.

“Some use a bit more water, some use a bit less. Some use a bit more reagent, some use a bit less, but they’re all alike,” he said. “If you stand far enough back, they’ll probably look fairly similar when you average it out.”