Emerging tech addresses limitations in conventional brine evaporation method for increased domestic lithium production in North America.

Direct lithium extraction (DLE) technologies promise incredibly fast processing times (hours instead of months) and higher yields, broadening the range of usable brine resources across diverse geographical locations in North America.

DLE methods can vary widely, with some being more energy-intensive while others require higher amounts of water, acids, or reagents. Applicability and cost profiles differ according to brine composition and geographical location, with overall recovery techniques and equipment tailored to the resource.

Today's industry leaders have primarily implemented adsorption-based DLE technology driven by several factors: adsorption is the most understood and commercially proven DLE technology and requires minimal to no chemical usage – a method that is expected to continue leading the market over the next 5-10 years.

A report by IDTechEx on direct lithium extraction presents an in-depth analysis of DLE technologies and case studies of key industry players. It predicts DLE will disrupt the brine mining market as one of the fastest-growing technologies in the industry. With lithium prices dipping, this could prove to reduce costs and encourage the growth of domestic lithium production in the U.S.

The report, by Technology Analyst Jiayi Cen at IDTechEx, outlines the importance of new lithium extraction technologies: "The global lithium mining market is projected to grow at a compound annual growth rate (CAGR) of 9.7% between 2025 and 2035. The lithium mining industry plays a pivotal role in supporting the transition towards renewable energy and a low-carbon future," Cen wrote in her introduction. "Alongside this rapid growth, there is a growing awareness on sustainability throughout the battery value chain. Therefore, advancements in the lithium mining sector are crucial, as they determine how lithium supply can meet the surging demand in an economically and environmentally sustainable manner."

The world's lithium resources occur in hard rock deposits (most notably Australia, which is the number one lithium producer) and continental brines, the second most developed source. These deposits include salt lakes and flats primarily found in the lithium triangle spanning Bolivia, Chile, and Argentina but are also being explored in North America at California's Salton Sea and the Smackover aquifer in Arkansas.

Recent improvements and pilot projects using DLE technologies for recovering lithium from geothermal and oilfield brines have been gaining attention. While lithium concentration (or grade) is a key determinant, variables such as impurity content, pH, and temperature affect the viability of the DLE extraction method.

Conventional evaporation ponds, which have stricter brine quality requirements and rely on slow natural processes that take months or even years, are limited to targeting brines with high lithium concentration and low impurity content. However, DLE technologies may be able to expand the range of viable brine resources, enabling lithium extraction from lower-grade and high-impurity brines.

Six approaches

To take advantage of the full potential of lithium brines, extensive research and testing are being conducted on DLE technologies, with six distinct classes of DLE methods having emerged at different stages of development, per the IDTEchEx report.

The diversity in lithium brine resources necessitates the development of customized processes to determine the most promising and viable investment opportunities.

IDTechEx

Illustrating the six lithium extraction methods covered by the IDTechEx report, "Direct Lithium Extraction 2025-2035: Technologies, Players, Markets and Forecasts."

Adsorption-based – uses aluminum-based sorbents to capture lithium and water to release lithium salts; most companies and projects are applying this approach. This process is customizable to brines with high salinity. When the lithium-loaded sorbent is washed with water, it facilitates the release of lithium salts back into solution. As the process requires high water consumption, water recycling techniques are often employed in a trade-off of increased energy consumption.

Ion exchange – is the second most advanced technology in the field and typically uses manganese or titanium-based sorbents to capture and release lithium salts by washing with an acid, such as hydrochloric acid, to produce lithium chloride salt.

A key advantage of this method is the ability to extract lithium from lower-grade brines and produce solutions with higher lithium concentrations than that of adsorption DLE. However, the use of acids presents sourcing and transportation challenges if they are not produced on-site. Additionally, the faster rate of degradation and dissolution of the ion exchange components in acid requires monitoring.

Unlike adsorption, ion-exchange DLE performance and economic viability require further improvement before commercialization. Companies like Standard Lithium and Controlled Thermal Resources have favored adsorption DLE over ion exchange DLE to avoid acid use.

Solvent extraction – the development and testing of the remaining four classes of DLE have lagged behind adsorption and ion exchange; solvent extraction operates by selectively dissolving lithium from brines into solvents. This approach typically utilizes multi-component solvent systems comprising extractants, co-extractants, and bulk solvents.

While solvent extraction has shown promise in producing high-purity lithium solutions, it remains underdeveloped but is being pursued by companies such as Adionics and Ekosolve.

The lack of effective lithium extractants and a limited understanding of process optimization for achieving high lithium selectivity and extraction efficiency have slowed this process development.

Membrane technologies – originally used for water treatment and desalination, membrane technologies can be categorized into pressure-driven, thermally-driven, and electrically-driven processes.

Conventional membrane structures and materials require modification to address scaling and fouling, as well as additional stages to achieve a high-purity lithium stream. Specialized lithium-selective membranes, on the other hand, largely remain in the development phase, and challenges such as chemical stability and scalability still need to be overcome for practical use.

Lastly, electrochemical and chemical precipitation remain chiefly under study and require further research and development before they can be scaled up for commercial production.