ORNL research aims to develop lithium recovery technology

ORNL research aims to develop lithium recovery technology Geothermal plant, Salton Sea/ California (source: flickr/ monikomad, creative commons)
Carlo Cariaga 29 Mar 2022

Research being done at ORNL is exploring the use of a low-cost high-selectivity sorbent for the recovery of lithium from geothermal brine.

Scientists from the Oak Ridge National Laboratory (ORNL) are currently working with the DOE’s Critical Materials Institute and industry partner All-American Lithium to develop a technology for recovering lithium from geothermal brine. So far, the use of a lithium-aluminum-layered double hydroxide chloride (LDH) sorbent is the most promising  based on a relatively low cost and high lithium selectivity.

The ORNL joins a long list of research institutes and private entities that are developing technologies for geothermal lithium recovery. Last month, we reported on a DOE-funded joint research led by the US Lawrence Berkeley National Laboratory that seeks to quantify and characterize the lithium resource in the geothermal reservoir of Salton Sea, California.

The LDH sorbent being tested by the ORNL has the advantage of being highly selective for lithium. This means that it “not only adsorbs a large percentage of the available lithium, but it doesn’t recover other minerals in the process.” according to ORNL Corporate Fellow Parans Paranthaman. Preliminary tests have shown the sorbent can remove more than 90% of the lithium from a simulated geothermal brine.

The research team is also investigating the use of a membrane that will increate the lithium chloride concentration in the brine before it goes into the sorbent. This helps precipitate out sodium chloride and potassium chloride, in turn making the sorbent more efficient.

ORNL estimates that up to 15,000 tons of lithium carbonate per year can be recovered from a 50-MW geothermal power plant. This means that the Salton Sea geothermal resource can supply more than the domestic demand for lithium, as already pointed out in a previous article.

The DOE’s National Blueprint for Lithium Batteries 2021-2030 report notes that the worldwide lithium battery market is expected to grow by a factor of 5 to 10 within the next decade. This impending increase in lithium will be a challenge for the U.S. because of the country’s dependence on imports mostly from China, Australia, and South America.

Source: ORNL