by David Snydacker, President and CTO

It’s a pivotal time for the lithium industry. As China achieves unparalleled economies of scale across the electric vehicle supply chain, U.S. and European companies are working to adopt new technologies to reduce costs and build diversified supply chains. For lithium producers, this means adopting new technology to unlock brine resources with lower costs and at new sites closer to home.

Evaporation ponds are the simplest way to extract lithium from brine, but they have only been successful on a large scale at two projects in the Atacama Desert, where brine has the world’s highest lithium concentration—around 2,000 ppm. Even with these high lithium grades, evaporation ponds typically recover only around 50% of the lithium.^1,2

Direct lithium extraction (DLE) technologies promise to redefine the lithium industry with a new approach to brine production that is low cost, environmentally friendly, and scalable. These technologies are designed to harvest lithium from diverse brine resources around the world, including not only traditional salt flats but also lakes, oilfields, and geothermal power plants. Unlocking the commercial viability of these brine resources will empower us to meet future EV battery demand with a more affordable and more diversified supply chain.

DLE technology has been through several hype cycles, and skepticism is understandably high. Let’s go a level deeper to examine what’s gone wrong with conventional DLE technology and how new technology can close the gap.

The Dawn of Direct Lithium Extraction

In the 1990s, the American company FMC pioneered the first DLE technology with aluminum-based Layered Double Hydroxide (LDH) adsorbent materials. These LDH adsorbents were deployed at the Hombre Muerto project in Argentina with a hybrid configuration using evaporation ponds and were able to achieve 42% lithium recovery from a 750 ppm brine.³ Despite the continued reliance on evaporation ponds, this was a major step forward toward unlocking greater lithium production and served as an inspiration for future innovators in DLE technology, including the team at Lilac.

Over the past three decades, many companies have attempted to refine LDH technology and deploy it at new lithium sites in a truly “direct” configuration without evaporation ponds. However, there has been little success with this approach. Nearly all successful deployments of LDH have required evaporation ponds or large quantities of water, creating permitting challenges and limiting production capacity.

Most new production with LDH technology has been in western China leveraging byproduct streams associated with potash production, which is not relevant to most new lithium projects. In the U.S. and Europe, LDH has failed to deliver any production capacity, despite decades of piloting. The two biggest challenges for LDH are brine impurities and lithium concentration.

The Challenge of Brine Impurities

While LDH materials can be decent lithium adsorbents, the peer-reviewed literature shows that these materials are often better at adsorbing other impurities. This is not ideal for DLE applications where impurity levels are typically high.

LDH materials have been shown to adsorb anions (negatively charged species) like borate, arsenate, sulfate, and carbonate.^{4,5,6,7,8,9,10,11} They also adsorb large concentrations of cations (positively charged species) like calcium, potassium, lead, cadmium, and mercury.^{12,13,14,15,16} LDH materials can even adsorb dyes from textile effluents.¹⁷ Many of these impurities like lead and arsenate can out-compete lithium for adsorption sites in the material, reducing lithium adsorption capacity and recovery, and in some cases damage the material. Other adsorbed impurities including calcium, borate, and potassium need to be removed downstream, adding to processing cost.

Unfortunately for LDH, impurity concerns like this tend to be ubiquitous. Lilac has analyzed brine samples from around the world and found lead and arsenic across both U.S. and European brines; sulfate and carbonate throughout many South American salars; and borate in most brines globally.

Lithium brines can have very different chemical compositions. South American brine (left) contains impurities such as boron, sulfate, and carbonate, which are often colorless. North America brine (right) includes other impurities at higher levels, visible in the photo.

To manage around impurities, many companies have turned to pre-treatment to remove impurities from the brine prior to lithium uptake.^12,16,18 Metals like iron and manganese can be removed cheaply using lime, but other impurities, such as lead, arsenic, sulfate, and borate, present a bigger challenge. Removing lead and borate is typically expensive and involves toxic byproducts and solvents, respectively. Removing anions like sulfate and arsenate is much more challenging and usually not economically viable.

The Challenge of Lower Concentration Brines

Brines with lower concentrations of lithium also present a challenge for LDH technology. When brine grades are lower, more lithium must be removed from the LDH adsorbent to achieve acceptable lithium recoveries due to intrinsic materials properties. This is achieved by flushing the adsorbent with more dilute solution to release the lithium from the material.^19,20,21

Removing more lithium from the material leads to faster degradation of the materials—at the atomic scale the LDH crystal structure is transformed into an inactive structure known as Gibbsite.^19,22 Variations in brine pH can also harm the LDH materials, leading to a narrow pH operating window and a need for acid/base reagents to adjust pH.^6,10,13,22

Striving for Meaningful Lithium Recoveries

Despite these known limitations, LDH technology is not standing still. Recent advances in materials engineering appear to have enabled higher recoveries from mid-grade brines. However, outside of potash effluents in China, additional production with LDH has been minimal. Furthermore, there is little evidence that the impurity issue has been solved effectively, as there is still no meaningful LDH production from brines in the U.S. or Europe.

While high lithium recovery numbers are often touted in LDH pilot announcements, they have not translated into high recoveries in commercial operation. This may be because pilots can be optimized to showcase lithium recovery, while neglecting to optimize for impurity selectivity, water usage, LDH material durability, equipment sizing, and production costs—all of which are crucial for commercial viability.

Brines are defined by their lithium concentrations and the presence of different impurities, and every brine is unique. To unlock broader resources, developers need a technology that can withstand challenging brines—not just ideal ones. This is especially true in regions like the U.S. and Europe, where many brines have low lithium grades and high impurity levels.

Overcoming Challenges with Ion Exchange Technology

Ion exchange (IX) DLE excels at selectively capturing lithium ions and rejecting a broad swath of impurities, including some of the most challenging impurities like calcium, boron, lead, and arsenic. IX technology has been used in various applications for a century but has only recently been adapted for lithium extraction. Historically, the main hurdle to overcome was durability of the ion exchange media (IXM), which is critical to achieving a low production cost.

Solving the IXM durability challenge is one of Lilac’s core advancements, enabling this highly effective technology to be used economically for lithium extraction. Lilac’s IX technology can handle a wide variety of brine chemistries, all while delivering high lithium recoveries at a low cost of production. This technology also reduces consumption of fresh water by 10x. This breakthrough enables large-scale lithium production with attractive project economics for brine resources in the U.S. and around the world.

See the table below for Lilac’s lithium recovery and impurity rejections across four different brine types.

Download the full white paper for more data.

Redefining the Future of Lithium Extraction

As the race for scalable DLE technologies continues, companies focused on LDH technology are running into the fundamental limits of LDH materials properties. By contrast, Lilac’s IX material has intrinsically superior properties. This has allowed us to achieve higher performance, surpassing decades of work on LDH materials. We believe IX will only widen the gap as we further refine and optimize its capabilities.

This is an inflection point for DLE innovation. We are on the verge of transforming lithium production with a technology that promises to deliver faster, cleaner, and cheaper lithium extraction for brine resources globally. With IX technology leading the way, we’re setting a new standard for modern lithium extraction, making it more efficient, sustainable, and scalable to support the electric vehicle revolution.

Lilac demonstration plant, Jujuy Province, Argentina

Discover how Lilac’s breakthrough IX technology is redefining DLE.
Download our White Paper and see the data now.

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