Highlights

• China's rare earth processing monopoly lies in midstream separation and solvent-extraction capacity, not upstream mining—combining ore-specific flowsheets with advanced reagent innovation to control over 90% of global supply.
• South China's ionic clay in-situ leaching secures China's command of critical heavy rare earths (Dy, Tb) essential for EV magnets and wind turbines, creating a strategic chokepoint.
• De-risking requires full-chain build-out beyond mines: separation plants, SX capacity, metallization, and magnet manufacturing, with ESG transparency (LCAs, ammonium-free leaching) becoming a capital gating factor.

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Lead author Zerui Lei, Northeastern University, Shenyang (opens in a new tab), with co-authors Xiaolong Zhang, Wenbo Li, and Yuexin Han, earlier this year published a technical review, “Rare Earth Processing in China” (Mineral Processing and Extractive Metallurgy Review, 2025), arguing that China’s advanced flotation, leaching, solvent-extraction, and combined flowsheets have both raised recovery and—under newer regimes—reduced environmental burdens. The authors further validate the gap between Chinese rare earth refineries and the rest of the world’s nations.

Through case studies at Bayan Obo (Inner Mongolia), Sichuan (bastnäsite LREE), and South China ionic clays (HREE), the paper catalogs reagents, circuits, and greener approaches (e.g., ammonium-free leachants, bioleaching pilots). The authors contend that continuous reagent innovation and process integration (gravity/magnetics plus flotation plus hydromet) underpin China’s processing leadership—and, by extension, the global bottleneck.

The team collaborated on this study at the National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources, Northeastern University (opens in a new tab), Shenyang, China.

Study Methods—What They Examined

This is a narrative/technical review. The authors synthesize bench, pilot, and industrial literature on:

Category	Description
Physical Beneficiation	Gravity and high-gradient/superconducting magnetic separation used to produce rare earth pre-concentrates before chemical treatment.
Flotation Chemistry	Employs hydroxamic-acid and organophosphorus collectors with tailored depressants and activators; operates through closed-circuit flowsheets to selectively recover RE minerals.
Hydrometallurgy	In-situ leaching for ionic clays, and acid/alkali routes for bastnäsite and monazite ores. Downstream purification uses solvent extraction and precipitation (oxalate, carbonate methods) to refine mixed rare earth solutions.
Emerging “Green” Tracks	Adoption of ammonium-free leach salts, microbial bioleaching (e.g., A. ferrooxidans, A. niger), and reagent/water recycling to reduce environmental impact
Case Studies	Comparative analysis of processing choices, recoveries, and environmental trade-offs at China’s three key hubs: Bayan Obo (mixed LREE deposit), Sichuan (bastnäsite LREE), and South China IADs (HREE-rich ionic clays).

Findings, Plainly Stated—China’s Processing Edge

What follows in the table are key insights from this study:

Scale plus Integration equals Control	China combines ore-specific processing flowsheets with advanced solvent-extraction expertise, producing reliable mixed and separated rare earth oxides that anchor its global dominance. Absolutely key and multiple experts in the REEx network confirm this fact.
Ionic Clays equals HREE	In-situ leaching of South China’s (also Myionic clays secures China’s command of heavy rare earth elements (Dy, Tb), which are essential for high-temperature permanent magnets used in EVs and wind turbines.
Reagent Innovation Matters	Ongoing R&D into collector blends, advanced depressants/activators, and ammonium-free or low-impact leachants has delivered measurable efficiency and ESG improvements in pilot and early-stage industrial plants.
Environmental Footprint Varies	Environmental performance differs regionally—higher impacts at Bayan Obo (legacy tailings, fluorine management), lower-impact circuits in Sichuan, and improving in-situ protocols in the South. Nonetheless, wastewater, ammonium-nitrogen, and tailings management remain significant sustainability challenges. And we know the devastating state of Myanmar’s heavy rare earth mining operations.

Implications—What Investors and Policymakers Should Take Away

Monopoly is midstream, not just mines

The chokepoint is processing and separation, where China’s reagent systems and SX capacity dominate.

De-risking requires a full chain build-out

Non-China strategies must fund separation, metallization, alloying, and magnet plants, plus recycling—not only mines.

ESG is a gating item

Projects that publish independent LCAs, ammonium-free leaching, and water/reagent recirculation will earn premium offtakes and cheaper capital.

Watch HREEs

Any curbs on Dy/Tb exports ripple straight into EV and wind supply. Ionic-clay substitutes or recycling breakthroughs are strategic alpha.

Limitations & Controversies—Read with Care

It’s a review, not new primary data.

Reported recoveries and “green” gains often derive from site-specific or pilot contexts; transferability isn’t guaranteed.

Environmental claims need audits.

The paper highlights progress, but persistent issues (ammonium effluents, tailings stability, fluorine handling) warrant third-party verification.

Monopoly does not equal inevitability.

The narrative risks implying permanence; targeted Western/Japanese/Korean investment and policy certainty can close gaps over time—especially in SX, metals/alloys, and magnets.

REEx Verdict—Actionable Signals

Consider using this review along with other evidence as a process playbook. Diligence should map each issuer to: (1) ore type & flowsheet fit, (2) reagent/energy intensity, (3) water/effluent plan, (4) SX capacity, (5) route to metal/alloy/magnet, (6) HREE exposure, (7) LCA transparency. Price upstream tonnage only when tied to credible midstream execution.

Northeastern University, Shenyang

Researcher	Institution
Zerui Leia	School of Resources and Civil Engineering, Northeastern University, Shenyang,
Xiaolong Zhanga	National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources, Northeastern University, Shenyang.
Wenbo Lia	National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources, Northeastern University, Shenyang
Yuexin Hana	School of Resources and Civil Engineering, Northeastern University, Shenyang; National-local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources, Northeastern University, Shenyang.

Citation: Zerui Lei, Xiaolong Zhang, Wenbo Li, Yuexin Han. “Rare Earth Processing in China.” Mineral Processing and Extractive Metallurgy Review (2025). https://doi.org/10.1080/08827508.2024.2449254 (opens in a new tab)

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