American technology shortens the years of lithium extraction.. Will the “white gold” market shake? | sciences

Researchers at Columbia University’s School of Engineering have developed a new, rapid technique to extract lithium directly from groundwater brines, using a heat-sensitive solvent, bypassing massive evaporation ponds that can take years and deplete precious water resources.

The researchers believe that this method will be effective with low-quality lithium sources that current technologies struggle to use, and thus this method is expected to contribute to solving one of the most environmentally polluting problems of clean energy.

Challenges of lithium extraction

Global demand for lithium is increasing dramatically as the electric vehicle industry ramps up and larger battery systems are built to support wind and solar power, but lithium production remains a slow and environmentally expensive process.

Dr. Ngai Yen Yip, associate professor of Earth and Environmental Engineering at Columbia University, said in his statements to Al Jazeera Net: “The lithium used in batteries is currently produced mainly from two types of sources: solid rock minerals and lithium-rich brine solutions.”

He adds: “In hard rock mining, minerals containing lithium are extracted, then crushed, processed and chemically converted into lithium products. In brine-based production, lithium-rich salt water is extracted to the surface and usually concentrated through large evaporation ponds before being chemically treated to produce lithium carbonate or lithium hydroxide.”

“The traditional brine method is widely used, but it is slow, requires large areas of land, and is highly dependent on favorable climatic conditions, particularly dry environments where evaporation is effective, which is less suitable for many emerging lithium sources, such as geothermal brines and oil field brines, where lithium may be present in relatively low concentrations and mixed with much larger amounts of sodium, potassium, calcium, magnesium, and other ions,” Ngai adds.

According to Ngai, the main challenge is that the demand for lithium is increasing rapidly as a result of the spread of electric cars and energy storage technologies, but current production methods are not always fast, efficient, or environmentally ideal.

Numerous reports have indicated that producing lithium using the traditional fumigation method takes a long time, requires large areas of land, and may consume or damage water resources in sensitive areas.

“This is why there is strong interest in direct lithium extraction techniques, which can selectively remove lithium from brine solutions without relying on large evaporation beds,” the researcher adds.

New way

According to the research team, the new method showed superior selectivity during tests. It extracted lithium at rates up to ten times the rate of extraction of sodium, and twelve times the rate of extraction of potassium. It also removed magnesium, one of the most common contaminants in lithium brines, through a chemical precipitation process that separates the unwanted material.

In this regard, Ngai says, in his statements to Al Jazeera Net: “Our method is called “selective extraction with a switchable solvent,” and it uses a special type of liquid solvent whose behavior changes with temperature. At a low temperature, the solvent can absorb dissolved salts and some water from the brine solution.”

He adds: “More importantly, it shows a preference for extracting lithium over other common ions such as sodium and potassium, and after lithium extraction, when we slightly heat the solvent.”

According to the study, at a higher temperature, the solvent becomes less compatible with salts and water, releasing a small stream of lithium-rich water, and the solvent can then be reused.

“Simply put, the solvent acts as a temperature-controlled carrier,” Ngai says. “It absorbs lithium from the brine at a certain temperature and then releases a stream of purer lithium at another temperature. Our method differs from many traditional solvent extraction methods in that it does not rely on chelating chemicals that bind directly to the lithium, nor does it require the use of a chemical extraction agent to release the lithium.”

“Instead, the separation depends on the tendency of the solvent to water and ions, which changes with temperature,” he added. “In our study, we showed that this method is able to extract lithium preferentially over sodium and potassium, even when the lithium concentration is much lower than that of competing ions. We also demonstrated the effectiveness of this method using a simulated geothermal brine from Salton Lake, and demonstrated the possibility of reusing the solvent for several cycles.”