Watch magnets pull critical elements from wastewaterS. Himmelstein | July 25, 2021
Demand for lithium, cobalt and other critical elements is increasing for the manufacture of semiconductors, wind turbines and batteries, straining the global supply chain and increasing U.S. reliance on imports. Geothermal brines, produced water and other industrial wastes represent a previously untapped source of industrially valuable rare earth elements that could soon be exploited with a nanotechnology-based extraction system developed at the U.S. Pacific Northwest National Laboratory (PNNL).
Initially developed to target lithium recovery, the approach is less energy- and cost-intensive than ion exchange filtration systems conventionally used for this application. Magnetite nanoparticles line an adsorbent shell that selectively binds target elements or compounds in solution. When introduced into brines and exposed to magnetic forces, the nanoparticles transport the attached materials toward the magnet for subsequent recovery.
The PNNL technology, licensed by start-up Moselle Technologies, is being applied to produced water from oil and gas fields to demonstrate its utility for lithium extraction. Additional demonstration projects will test potential applications at lithium mines in Nevada and Canada and evaluate sorbents for cesium recovery from geothermal brines in New Zealand.