Highlights

• Tsinghua researchers developed ultrafast electrothermal calcination that heats plant biomass to 1,000°C in 20 seconds, achieving 97% rare earth recovery efficiency compared to traditional slow furnace methods.
• The rapid heating process creates porous carbon residues that prevent the formation of stable mineral phases, dramatically improving downstream acid leaching performance with lower energy and carbon emissions.
• Despite laboratory success, phytomining faces major scaling challenges, including low metal concentrations per hectare and uncertain economics, positioning it as a complementary technology rather than a replacement for conventional mining.

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A new scientific study explores how plants can be usedto recover rare earth elements through “phytomining.” The research, led by Bing Deng (opens in a new tab), Assistant Professor at Tsinghua University, proposes an ultrafast electrothermal heating process that dramatically improves the extraction of rare earth elements from plant biomass. While the results show impressive laboratory efficiency and potential environmental benefits, significant economic and scaling challenges remain before phytomining could meaningfully contribute to global rare-earth supply chains.

Can Specialized Plants be Metal Miners?

The new study, led by Bing Deng and collaborators, reports a novel method for recovering rare earth elements (REEs) from plant biomass using ultrafast electrothermal calcination, potentially improving the practicality of “phytomining”—a process where plants absorb metals from soil and are later harvested for resource recovery. Published in Communications Materials (opens in a new tab), the research demonstrates that brief electrical heating pulses reaching roughly 1,000°C for about 20 seconds can dramatically improve the efficiency of rare-earth extraction from biomass, achieving recovery rates approaching 97% during subsequent dilute-acid leaching. The work suggests a possible lower-carbon, more efficient alternative to traditional furnace calcination, though it remains at the experimental stage and is far from industrial deployment.

The Science Behind Phytomining

Phytomining relies on metal-accumulating plants that absorb rare earth elements from soils, mine tailings, or contaminated land. When harvested, the plant material contains trace metals embedded within complex organic tissues. Historically, extracting those metals has been difficult. Conventional recovery methods require long furnace heating followed by acid leaching, processes that are energy-intensive and sometimes chemically inefficient. During slow heating, rare-earth elements can become locked in stable mineral compounds that resist dissolution.

This bottleneck has limited phytomining’s practical application despite years of research interest.

Study Methods: A Radical Shift in Heat Treatment

The Tsinghua team tested a different approach: rapid electrothermal calcination.

Instead of hours in a furnace, plant biomass enriched with rare-earth elements was exposed to short electrical pulses that rapidly heated the material to ~1,000°C in seconds. The entire thermal treatment lasted roughly 20 seconds, followed by mild acid leaching.

The ultrafast heating decomposed organic plant matter, creating a porous, carbon-rich residue that exposed rare earth elements to more direct chemical extraction. Because the heating cycle is extremely short, the process avoids the formation of stable mineral phases that normally trap metals during slow calcination.

Key Findings

The study reports several notable outcomes:

• Extraction efficiency reached roughly 97% in laboratory experiments
• Rapid heating created highly porous residues that improved leaching performance
• Non-equilibrium heating conditions prevented the formation of hard-to-dissolve rare-earth mineral phases
• Preliminary life-cycle analysis suggests lower energy consumption and carbon emissions compared with conventional furnace processing

Together, these results indicate that electrothermal treatment may significantly improve the downstream recovery stage of phytomining.

Limitations and Real-World Constraints

Despite promising laboratory performance, some key limitations remain.

First, phytomining itself produces extremely low concentrations of rare earth elements compared with conventional mining. Even if recovery efficiency improves, the total metal yield per hectare may remain small. Second, the electrothermal process requires specialized electrical equipment and energy input, raising questions about scalability and cost. Finally, the study focuses primarily on controlled laboratory biomass samples, not full agricultural or mine-tailings operations.

In short, the approach demonstrates technical feasibility, but commercial deployment remains uncertain.

Implications for the Rare Earth Supply Chain

The study highlights an emerging theme in critical mineral research: unconventional resource pathways.

If scalable, phytomining combined with advanced processing could potentially:

• Recover rare earths from mine waste or contaminated land
• Provide localized resource recovery in regions without conventional mines
• Contribute to circular or distributed supply chains

However, from an industrial perspective, phytomining remains orders of magnitude smaller than conventional mining and separation systems, particularly compared with large-scale solvent extraction operations used globally. The technology, therefore, represents an interesting complement—not a replacement—for traditional rare earth production.

Conclusion

Bing Deng and colleagues demonstrate that ultrafast electrothermal calcination can dramatically improve the recovery of rare earths from plant biomass, addressing a longstanding technical barrier in phytomining research. While the method offers promising efficiency and environmental benefits in laboratory experiments, significant hurdles—including biomass yield, process scale, and economics—must be overcome before plants can meaningfully contribute to global rare-earth supply.

Still, the study illustrates how innovations at the intersection of biology, materials science, and advanced processing technologies may expand the toolkit for recovering critical minerals in a resource-constrained world in the future.

Citation: Deng, B., et al. Sustainable rare earth extraction from phytomining by rapid electrothermal calcination. Communications Materials, 2026. Published within the Nature portfolio.