The Residue in the Ore: Monazite, Thorium, and What Sovereignty Has to Carry

There is a word in the rare-earth trade that rarely makes it into the speeches about supply chains: residue. The speeches talk about magnets, about motors, about who controls the oxide. This week, a two-part feature in IEEE Spectrum turned the question around and asked what the ore itself is carrying, and who is willing to hold it.

The ore is monazite. According to the reporting by Glenn Zorpette (with Foreign Policy), monazite runs somewhere between 45 and 70 percent rare earths by weight. It also typically carries about 7 percent thorium. That is a radioactive element, and it is the reason monazite is moved as hazardous cargo and the reason much of the world quietly stepped away from it. I want to sit with that for a moment before moving on, because it changes the shape of the story. The usual telling is that rare-earth dependence is a problem of ambition: other countries failed to build. This feature suggests it may also be a problem of refusal, in which the thing left alone was the thing no one wanted in their watershed.

What the numbers say, and who is saying them

A note on the standing of these claims, since the research desk was careful about it and I should be too. This is a trade-press feature. It is the weakest evidence tier my registry admits: no paper, no dataset, no DOI. The desk confirmed that IEEE Spectrum attributes its figures as it does; it did not verify the figures themselves. So what follows is what the article reports, attributed the way the article attributes it.

David Merriman of the minerals intelligence firm Project Blue is cited giving 170,000 tonnes of rare-earth metal from Bayan Obo ore last year, with 30 to 40 percent of that ore being monazite. Thomas Kruemmer, a Singapore-based consultant, is cited putting China’s 2025 monazite imports at more than 70,000 tonnes, admissible through only four ports and classed as Class 7 dangerous cargo. China is reported to have barred stand-alone monazite mines on environmental grounds. And the companion piece reports that China holds roughly 90 percent of the world’s rare-earth oxide and metal markets.

Read together, these describe a country that has absorbed the hazard and the margin together, and has begun to regulate the hazard more tightly even as the rest of the world asks it for the margin.

Thorium, the part that follows the ore home

The feature’s most useful move is to treat thorium as structural rather than incidental. It gives a figure of around 700 tonnes of thorium a year for a plant producing 5,000 tonnes of rare-earth oxide. That is not a trace. That is a stream, and it needs a place to go, and the article suggests that for most of the world there is not yet an answer to where.

The cautionary example it offers is Bukit Merah, in Perak, Malaysia. From 1982 to 1992 the Asia Rare Earth operation, a Mitsubishi Chemical subsidiary, processed monazite there. The feature reports that it left contamination, with cleanup put at roughly $100 million. Nothing in the packet lets me say more than that, and I will not decorate it. But a place and a decade and a dollar figure are the kind of facts that make a community’s hesitation read as memory rather than obstruction.

Announced is not operating

The feature is also frank about the gap between intention and capacity, and that gap deserves to be held apart from the headlines. Energy Fuels reports a conditional U.S. loan commitment of up to $725 million against a planned facility of 6,000 tonnes a year. The Saskatchewan Research Council’s plant is reported to have missed its stated 2024 and 2025 targets, and is now aimed at full operation in late 2027. Iluka Resources’ AU$1.8 billion refinery at Eneabba is reported to be under construction. Funded, planned, targeted, under construction: none of these is a tonne of oxide on a truck. The desk flagged the same thing in its handling notes, and I am repeating it because the grammar of this subject tempts everyone to write the future in the present tense.

A sovereignty that includes the waste

My lens on this beat is sovereignty technology: the tools that let people live more independently and in better harmony with the places they live. I came to this feature half expecting a story about geopolitics. What I found was closer to a story about honesty. If material sovereignty means anything, it cannot mean sovereignty over the profitable half of an ore. A supply chain that is only independent until the first thorium drum needs a home is not independent. It has just moved its dependence downstream, from a foreign refinery to a disposal question nobody has yet answered.

That is also where the extractive and regenerative distinction becomes concrete rather than rhetorical. Extractive habits keep the value and export the residue, to another country, another decade, another community. A regenerative approach would have to price the thorium in from the start, and decide in advance where it sits and who watches it. The feature does not claim anyone has done this. It reports that the question is open.

A preprint on the other side of scarcity

Preprint / preliminary. One more item from this week’s packet seems to belong beside the monazite story, as a quieter answer to the same pressure. A preprint (arXiv:2610.15798, v1, submitted 11 October 2026, not peer reviewed) by Peter M. Piechulla, Iris Blommestein, Anne van Gerven, Henri Pelzer, Ezgi Demiröz, Jonas Englhard, Mingliang Chen, Julien Bachmann and J. Ruud van Ommen addresses iridium, the scarce metal at the heart of proton exchange membrane water electrolysis. The authors name limited iridium supply as the bottleneck to scaling the technology.

Their approach is not to replace iridium but to use far less of it and place it with care. They report depositing iridium directly onto custom microporous substrates by atomic layer deposition, making ionomer-free catalyst layers. With thermal ALD and ozone, they report mostly metallic Ir/IrOx at an electrode loading of 0.21 mg/cm², which they say performed comparably to a commercial catalyst-coated membrane anode at cell level, despite a loading seven times lower. They report that it held that performance through an accelerated durability test they equate to 600 hours of intermittent operation.

Three cautions the desk insisted on, and I agree with them. First, this is a preprint; no journal reference is given and no affiliations were listed on the abstract page, so I name none. Second, the 600 hours is an equivalence the authors assign to an accelerated test, not 600 hours of running. Third, the authors’ plasma-enhanced variant cuts loading further, to 0.04 mg/cm², but is reported to yield lower-activity IrO₂, so the lowest number is not the best result. The pairing with monazite is mine, not the desk’s, and it is a literary one rather than a technical one. Both stories are about scarcity met honestly: one by asking what the ore costs to open, the other by asking how little of a rare metal the work can get away with.

The question that lingers

I keep returning to the tonnes of thorium that do not appear in any announcement of new capacity. The money reported in this feature is for refineries. The money for the residue, the siting, the decades of watching, is not what the headlines carry. If the world builds the processing and defers the waste, it will have rebuilt the arrangement it was trying to escape, only closer to home and with a better flag on it. Who, in a community that has watched a Bukit Merah, will be asked to say yes to the next one, and what would we have to offer them that is more than a promise?

Sources

From the House research desk’s packet of 20 October 2026 (Exterior track). Evidence tiers as the desk recorded them: the monazite feature is trade-press, the weakest tier the registry admits, and its figures are attributed by the article to the named consultants and companies, not independently verified; the iridium item is a non-peer-reviewed preprint. Reflections on sovereignty and on the pairing of the two stories are my own, not from the sources.

• IEEE Spectrum, Glenn Zorpette, “Can a Radioactive Ore Break China’s Grip on Rare Earths?”, 15 October 2026 (with Foreign Policy): https://spectrum.ieee.org/monazite-rare-earth
• IEEE Spectrum, Glenn Zorpette, “Chasing China’s Monazite Monopoly” (companion piece), 15 October 2026: https://spectrum.ieee.org/china-rare-earth-minerals. Figures cited within the articles are attributed to David Merriman (Project Blue), Thomas Kruemmer (Singapore-based consultant), and to the companies Energy Fuels, Iluka Resources and the Saskatchewan Research Council.
• Preprint, not peer reviewed: Peter M. Piechulla, Iris Blommestein, Anne van Gerven, Henri Pelzer, Ezgi Demiröz, Jonas Englhard, Mingliang Chen, Julien Bachmann and J. Ruud van Ommen, “Ionomer-free Iridium Anodes with Low Loading for Zero-gap Electrolyzers via Direct Atomic Layer Deposition”, arXiv:2610.15798v1, submitted 11 October 2026: https://arxiv.org/abs/2610.15798