Lithium Extraction from Volcanic Clay


Lithium powers our lives today via batteries for phones, computers, household electronics, and electric vehicles. The soft, silvery-white metal, known for its light weight, contributes remarkable power-density in lithium-ion batteries thanks to a single valence electron that the element gives up easily for cation formation.

With burgeoning markets for electric cars and lithium-ion batteries, and an increasing number of large-scale energy storage projects worldwide, researchers predict an increasing need for lithium in the future. One study from the University of Michigan projected a steady growth in demand for lithium up until the year 2100. Smithsonian Magazine reports that the global need will be an estimated 12 million and 20 million metric tons. While scientists at the USGS confirm that global deposits are plentiful, it appears that the issue lies not in the amount of lithium on Earth, but in accessing and extracting it.

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Today most lithium is harvested from lithium brine—salty groundwater containing lithium leached from volcanic rock that collects in geologic basins. In arid regions like Nevada and Chile’s Atacama Desert, where the water evaporates quickly, the basins produce dense concentrations of lithium brine which can be pumped out and condensed in evaporation pools, and later extracted in chemical plants.

But a group of Stanford geologists, led by Professor Gail Mahood, believes that they have found another source. The team explored supervolcanoes worldwide. According to the USGS, a supervolcano is a large-scale volcano that at one point in time erupted with deposits covering more than 1,000 cubic kilometers. In the calderas of these volcanos, they discovered high concentrations of lithium contained in a type of volcanic clay called hectorite.

According to their study, published in Nature Communications, hectorite is a layered, white ashy substance that formed following a volcanic eruption when the clay absorbs lithium that has leached out of the volcanic rock. Today, hectorite clay is mined for use as drilling muds for the natural gas and oil industry, but lithium could be extracted from the clay if technology were developed to make it economical.

“[Mahood and her team] have identified how lithium is held in these high silica volcanic rocks,” LeeAnne Munk, a geologist from the University of Alaska, told Smithsonian Magazine. “It helps further our understanding of where lithium occurs within the Earth. If we don’t fully understand that then we have a hard time telling how much lithium we have, and how much lithium we can actually extract. They’ve helped advance the understanding of where lithium exists in the crust.”

Some of the researchers speculate that the discovery of these volcanic deposits of lithium could change the global politics of battery production by offering alternative sources. What are your thoughts? De Bug Web

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