Cost Only Half of China's, Zero Pollution? Evaluation of Japan's Hot Metallurgy Rare Earth Recycling Technology: Cost an

A Chinese analysis post published on October 30, 2025 (title: "Japan's Breakthrough in Rare Earth Refining Technology: Cost Half of China's and Zero Pollution") claimed that Japan's "thermal metallurgy recycling" technology has made revolutionary progress, with the current refining cost being only half of China's hydrometallurgy and achieving "zero pollution". Thermal metallurgy is also known as pyrometallurgy. This article, based on the latest publicly available data in 2025 (NEDO reports, IEA Critical Minerals Report, LCA database, patent and capacity statistics), scientifically examines and refutes the core content of the post. The conclusion is as follows:

The technological progress is real but not a "major breakthrough": The NEDO project in Japan is in the pilot stage, with a recovery rate of 98%, but it has not yet been commercialized.

The claim that the cost is "only half of that in China" is completely unfounded: the current direct cost is 10–50% higher, and the full life-cycle cost, under strict regulations, may be close but is far from being half.

The claim of "zero pollution" is seriously exaggerated: while there is no acidic wastewater in thermal metallurgy, the emissions of CO₂, NOₓ and dioxins are significant; its energy intensity is 1.8 to 2.5 times that of the hydrometallurgical process.

The prospects for large-scale application have been overly optimistic: The prediction that the cost will drop to 60–80% of that of the wet process by 2030 lacks independent verification and ignores the differences in energy prices and purity.

Geopolitical narratives obscure the technological essence: The US-Japan-Australia agreement is a political framework with limited technological contributions.

Ⅰ.  Current Status of Rare Earth Refining Technology: An Objective Comparison of Two Approaches

Ⅱ,Cost Analysis: How Does the Title "Only Half of China" Stand Up?

1. Direct production costs (OPEX, excluding environmental protection)

Conclusion: The current direct costs in Japan are 13% - 73% higher than those in China. It is definitely not "only half" higher.

2.Environmental protection treatment cost (after adding the surcharge)

Life cycle cost:

Japanese:$18.5–28.5 /kg

China (including environmental protection):$14.3–27.2 /kg

Under the regulations of the European Union / Japan,The total cost in Japan maybe 10-15% lower.

In China, The actual cost burden for the wet process is only $10–12 per kilogram (externalizing pollution).

Refute:The title's claim that "cost is only half of that in China" is seriously inaccurate. Even in the most optimistic scenario (2030, Japan's green electricity, capacity > 5,000 tons/year), the thermal metallurgy cost is projected to be **$12–16/kg**, which is still 80%–120% of China's wet process cost, rather than 50%.

Ⅲ,"Zero Pollution"? —— The Environmental Truth of Thermal Metallurgy

1. No acidic wastewater ≠ Zero pollution

Source:Ecoinvent v3.10, Japan METI Environmental Impact Assessment (2025)

2. Energy intensity is invisible pollution

The thermal metallurgy requires continuous smelting at a temperature of >1400℃, and the energy consumption is 1.8–2.5 times that of the wet process.

If using the Japanese power grid (carbon intensity in 2025: 420 gCO₂/kWh), the carbon footprint is higher than that of the wet process.

Only in the 100% green electricity scenario does the carbon footprint of thermal metallurgy drop to 60% of that of the wet process.

Refutation: "Zero pollution" is completely incorrect. Thermal metallurgy shifts pollution to the energy end. Under the current energy structure, the comprehensive environmental load (GWP + acidification + toxicity) is comparable to that of the optimized wet process.

Ⅳ,Scale-up prospects: Why is the prediction of "dropping to 60%" by 2030 unreliable?

The statement reads: "By 2030, the cost will drop to 60-80% of the wet process (less than 15 dollars per kilogram)."

Refutation basis:

Ⅴ,Geopolitical narrative vs. Technological reality

The US-Japan-Australia agreement was packaged as a "technical breakthrough catalyst", but in reality::

Refutation: Geopolitical competition cannot replace technological maturity. The number of China's rare earth patents (cumulative 48,000 by 2025) is 5.3 times that of Japan (9,000), and the gap in execution ability is 30 years.

Ⅵ,Conclusion: The choice of technology depends on the scenario, not on the marketing promotion.