Can Lithium, the Main Culprit of 'Environmental Destruction,' Be Extracted More Cleanly? [Tech Talk]

Lithium Evaporated from Salt Lakes
Environmental Damage Including Water Waste and Soil Pollution
US and UK First Attempt at 'Geothermal Lithium Extraction Method'

There is a mineral whose value has skyrocketed as secondary batteries have been identified as a key product in the transition to eco-friendly energy. It is lithium, the main raw material for today's lithium-ion batteries. The problem is that the distribution of lithium varies greatly by continent. Moreover, existing lithium extraction methods consume large amounts of water and even cause environmental pollution.

The scene of lithium extraction at the Chilean salt desert. Seawater has evaporated, revealing yellow lithium carbonate.
[Image source=AFP Yonhap News]

However, new technology that overcomes the limitations of these lithium extraction methods is currently being tested. If successful, secondary battery manufacturers will be able to source clean lithium from a wider range of countries.

Lithium is dissolved not only in salt lakes but also in groundwater

Salton Sea, a lithium deposit area in the United States [Image source=Desert USA]

Currently, most lithium is extracted from salt lakes, also known as salars. The method involves filtering lithium dissolved in saltwater to produce battery materials. Because of this, lithium deposits are concentrated in South American regions rich in salt flats.

However, not all lithium is dissolved in salars. There are areas with high lithium concentrations in groundwater located kilometers underground. Recently, one such groundwater lithium deposit has been discovered each in North America and Europe. These are the Salton Sea in inland California, USA, and the Cornwall region in the United Kingdom.

The difference between these two sites and traditional salar lithium deposits is depth. Lithium is buried beneath the Salton Sea, and in Cornwall, lithium is dissolved in groundwater flowing 3 to 5 kilometers underground. Because of this, the USA and the UK are developing unique extraction technologies different from conventional lithium extraction methods. This is called 'Geothermal Lithium Extraction.'

Drawing lithium from underground and self-generating power with heat

Underground lithium extraction method. [Image source=Konishi Lithium homepage]

The deeper you drill underground, the hotter it gets due to the Earth's core. Therefore, groundwater flowing deep underground (such as hot springs) is usually very hot.

Geothermal lithium extraction uses the heat of lithium-containing underground brine. First, a hole is drilled 3 to 5 kilometers deep and a pipe is inserted to pump the lithium-containing solution to the surface. Lithium is then extracted from this solution, chemically processed, and the lithium-depleted water is returned to its original location.

During this process, geothermal power generation is also carried out using the heat of the hot groundwater. Several geothermal power plants utilizing the heat of hot groundwater have already been established near Cornwall and the Salton Sea.

The electricity generated by extracting heat from the groundwater is supplied to lithium extraction facilities. The company 'Cornish Lithium,' responsible for the geothermal lithium extraction project in Cornwall, estimates that power generated from groundwater pumped up from 5 kilometers underground will be sufficient to operate the lithium extraction facilities and still have surplus electricity.

Will lithium production shed its 'environmental pollution' stigma?

The lithium salt flats in Chile. The lithium extraction process from salt lakes consumes a vast amount of water and causes pollution due to chemicals. [Image source=AP Yonhap News]

The significance of technology that can extract lithium without polluting the Earth's surface environment is considerable. Although lithium-ion batteries are regarded as a key technology to prevent air pollution, ironically, lithium extraction from salars causes massive environmental destruction.

To extract lithium from salars, lithium-rich saltwater is first poured into large pits called 'evaporation ponds,' where the water is left to evaporate naturally. Then, various chemicals are added to extract lithium from the salt deposits. Pumping water from the salar to the evaporation ponds consumes enormous energy, and the chemical treatment stage pollutes the soil.

Moreover, salar lithium extraction wastes a tremendous amount of freshwater. Approximately 2.2 million liters of water must be discarded to produce one ton (t) of lithium. Ultimately, the more evaporation ponds are created, the more conflicts between lithium developers and local residents will be inevitable.

Diversifying lithium production is also important for supply chain stability. According to the U.S. Geological Survey, the top three countries by global lithium reserves are Bolivia (22.7%), Chile (18.9%), and Argentina (16.4%), all concentrated in South America. In Asia, China holds a significant share (13.6%).

As seen in the case of the Organization of the Petroleum Exporting Countries (OPEC), if scarce resources are produced by only a limited number of countries, the global supply chain will be subject to international political power struggles. This is why the number of 'alternative lithium-producing countries' must increase beyond South America and China.

This content was produced with the assistance of AI translation services.