Flash Joule Heating.
I first read about this process when it emerged from a lab at Rice University a few years ago.
Big potential for extracting lithium from ore, rare earths from a variety of feedstocks, including E-waste, and coal ash.
A new one-step, water, acid- and alkali-free method for extracting high-purity lithium from spodumene ore has the potential to transform critical metal processing and enhance renewable energy supply chains. This study was published in Science Advances Oct. 3.
As the demand for lithium continues to rise, particularly for use in electric cars, smartphones and power storage, current extraction methods are struggling to keep pace. Extracting lithium from salty water is a lengthy process, and traditional methods that use heat and chemicals to extract lithium from rock produce significant amounts of harmful waste.
Researchers led by James Tour, the T.T. and W.F. Chao Professor of Chemistry and professor of materials science and nanoengineering at Rice University, have developed a faster and cleaner method using flash Joule heating (FJH). This technique rapidly heats materials to thousands of degrees within milliseconds and works in conjunction with chlorine gas, exposing the rock to intense heat and chlorine gas, they can quickly convert spodumene ore into usable lithium.
“This method reimagines how to harvest lithium from its most abundant ore, spodumene, a material that is abundant in the U.S.,” said Tour, co‑corresponding author of the study. “We can leapfrog monthslong water evaporation pools and dayslong acid leaching and then directly generate lithium chloride.”
Guided by thermodynamic calculations, the researchers exposed α-spodumene, a naturally occurring hard-rock lithium mineral, to FJH and chlorine gas. This one-step process eliminates the need for the traditional multistep acid roasting method, allowing lithium to be extracted directly as lithium chloride.
With a flash of electrical current, the mineral shifted from its stable α-phase to the high temperature-accessed β-phase, making lithium available for reaction with chlorine gas. The lithium then vaporized as lithium chloride, while aluminum and silicon compounds were left behind. All of this was complete within seconds.
“Present techniques rely on multistep, chemically intensive treatments,” said study co‑corresponding author Yufeng Zhao, an associate professor of physics at Corban University and visiting professor at Rice. “The unique aspect of this method is the combination of rapid, uniform heating and favorable thermodynamics, which together enable practical and selective extraction.”
Traditional methods, from acid roasting to brine evaporation, simply weren’t designed for ultrafast separation, said Shichen Xu, the first author of the study and a postdoctoral researcher at Rice.
“Our controlled, rapid-heating approach overcomes kinetic barriers that have hindered single‑step extraction for decades,” Xu said.
Findings and broader significance
The researchers achieved nearly instantaneous lithium extraction from spodumene, producing lithium chloride with 97% purity and 94% recovery, significantly outperforming traditional methods that can take days to months.
“This method paves the way for local, small-footprint lithium processing units or large-scale units for massive waste mining operations,” said Justin Sharp, co-first author and research assistant. “It’s a real paradigm shift. We can now envision battery-grade lithium production without acids, without large waste outputs and without waiting weeks.”
Additionally, a startup from Tour’s lab, Flash Metals USA, is already scaling this technology for metals extraction from waste.
“They would be able to rapidly implement this method into their production line once their pilot plant begins operation early next year,” Sharp said.
Environmentally, the elimination of acid and alkali significantly reduces waste burden. Economically, shorter processing times and simpler infrastructure could lower costs and decentralize lithium supply. Academically, the work demonstrates the rapid, acid-free extraction of lithium from natural ore, raising possibilities for applying FJH and chlorine gas to other strategic minerals.
A new process makes it easier to recycle the chemical elements used to make the strongest permanent magnets. These rare earth magnets are used in hard drives and EV motors. Beyond their use in magnets, rare earth elements are used in lasers, glass, electronics, and a host of other applications important to modern daily life. They are expensive to mine and separate, and have long been a geopolitical football in trade wars, including the current one between the United States and China.
Compared with existing methods to recover rare earth elements, a process based on rapidly heating waste magnet material in the presence of chlorine gas uses one-third of the processing steps, reduces energy consumption by 87 percent, and produces 84 percent fewer greenhouse gas emissions. That’s according to a life-cycle analysis done by researchers led by James Tour, a chemist at Rice University. Their process is described in a recent paper in the Proceedings of the National Academy of Sciences.
The substantial quantities of fly ash and red mud generated contain abundant rare earth elements, gallium, and germanium. Their effective recovery not only mitigates environmental impacts but also unlocks significant economic benefits. This work developed an ultra-fast flash Joule heating activation coupled with acid leaching method to recover rare earth elements, gallium, and germanium from fly ash and red mud. By leveraging ultra-fast flash Joule heating, the approach recreates the silicon-aluminium crystal phases in red mud and fly ash under instantaneous, extreme high-temperature conditions (2000–3000℃), achieving an acid leaching recovery efficiency exceeding 80% for rare earths, gallium, and germanium. In contrast to conventional pyrometallurgical methods (such as alkali treatment activation followed by water/alkali washing and acid leaching) this instantaneous ultra-high-temperature Joule heating process enables efficient rare earth, gallium, and germanium extraction without alkali addition, demonstrating low energy and acid consumption.