Lithium extraction: prime time for brine

Story in Chemical Engineering describes technologies to process lithium, including a sorbent developed by the Critical Materials Institute (CMI). 

Researchers at Oak Ridge National Laboratory (ORNL; Oak Ridge, Tenn.) have seen very promising performance in extracting lithium from geothermal brine using iron-doped lithium-aluminum-layered double hydroxide chloride (LDH) sorbent and forward osmosis. “LDH sorbents can operate perfectly under geothermal brine conditions, around 95°C. Also, there is no need to add any reagents to adjust the pH for lithium extraction. It is a low-cost sorbent material with lithium-recovery rates greater than 95%,” explains Parans Paranthaman, corporate fellow at ORNL. In partnership with the Critical Materials Institute at Ames National Laboratory (Ames, Iowa;, ORNL has run column extraction using LDH sorbents for more than 500 h with multiple lithiation and delithiation processes. Each column cycle involves loading the sorbent with lithium chloride from brine, intermediate washing to remove undesired ionic species and final unloading of lithium chloride ions. ORNL has scaled up the LDH sorbent manufacture to kilogram-scale batches, and the team is prepared to begin testing at geothermal sites in the future.

Another crucial benefit of LDH sorbents is the promise for reuse and recovery. “LDH sorbents can be reused after hundreds of runs. LDH sorbent can also be recovered quickly if there was any failure during extraction, since we don’t need to add any reagents to delithiate, unlike ion-exchange sorbents or other solvent-extraction methods,” says Paranthaman. Also, since they are based on aluminum, rather than rare or precious metals, overall system costs will be lower.

Link to full story: Lithium extraction: prime time for brine