Highlights
- Rare earth elements are never mined in isolation, with dysprosium always occurring in complex mixtures requiring intensive separation processes.
- Project value depends on full-spectrum REE recovery and separation economics, not just isolated element quantities.
- Rare earth supply is constrained by the 'balance problem', where demand for one element impacts the entire mineral basket's economics.
In a recent LinkedIn commentary (opens in a new tab), renowned metallurgical chemist Professor Koen Binnemans (opens in a new tab) highlights a critical yet often misunderstood aspect of the rare earth sector: there is no such thing as a “dysprosium mine.” While terms like “lithium mine” or “copper mine” are common, investors and policymakers must understand that dysprosium, neodymium, and other rare earth elements (REEs) are never mined in isolation. Instead, they co-occur in complex mixtures that must be separated through intensive hydrometallurgical processes.
Binnemans explains that rare earths—comprising 17 chemically similar elements—are geologically entangled. Ore types such as bastnäsite and monazite are typically rich in light rare earths (LREEs), like neodymium. In contrast, xenotime and ion-adsorption clays—especially those from southern China—are richer in heavy rare earths (HREEs), like dysprosium and terbium. However, even in the best HREE-rich deposits, dysprosium represents only a small fraction of the total content. That means every tonne of dysprosium comes with many tonnes of LREEs that must be processed, stored, or sold—whether the market wants them or not.
The implications for supply chains are profound. There is no primary source for dysprosium production; instead, the supply of dysprosium is constrained by the economics of the entire rare earth element (REE) basket. Prices, availability, and project viability are all shaped by what is called the “balance problem,” a concept Binnemans elaborates on in his co-authored 2018 study (Rare Earths and the Balance Problem: How to Deal with Changing Markets?, Journal of Sustainable Metallurgy, 4:126–146 (opens in a new tab)). When demand spikes for one element (like dysprosium for high-temperature magnets), producers can’t easily scale output without also flooding the market with less in-demand REEs like lanthanum or cerium.
Extraction of individual rare earth elements (REEs) requires highly specialized separation technologies, with solvent extraction (SX) remaining the industrial standard. This reinforces the importance of midstream hydrometallurgy capacity, which is heavily concentrated in China. Without significant investment in solvent extraction and separation facilities elsewhere, countries may struggle to scale domestic production of critical magnet materials even if they mine REE-rich ores.
For retail investors in the rare earth space, the takeaway is clear to us at Rare Earth Exchanges (REEx): project value depends on full-spectrum rare earth element (REE) recovery, separation economics, and downstream demand, not on isolated metrics like “how much dysprosium is in the ground.” This also highlights the importance of vertically integrated strategies, diversified product portfolios, and policy support for midstream processing. We are working on our separation and refining ranking tool for retail investors.
Author: Prof. Koen Binnemans, Head of SOLVOMET Group, KU Leuven
Source: LinkedIn Post, May 31, 2025 | Referencing Journal of Sustainable Metallurgy (2018)
Not an unusual problem for miners, and the simple answer is “If it costs more to produce a product than what it can be sold for” you dump it. I know of Gold mines where high grade Silver had to be suppressed, because it was preferentially being consumed by the CN instead of leaching the Gold. Thankfully dropping Ce and Rn’s out of the pregnant liquor is a relatively easy process.