Antimony is a critical mineral. The Pentagon's FY2027 Defense Production Act budget names 23 others, and not antimony

Antimony has been on the US Geological Survey's list of critical minerals since the first edition in 2018. It is still there in the 2025 version, published in the Federal Register on 7 November last year, which covers 60 commodities. So it is odd to find it missing from the Department of War's FY2027 budget justification for Defense Production Act Purchases, the April 2026 document that sets out how the department plans to spend its Defense Production Act money.

The justification asks for $30.43bn, of which $477.3m is discretionary and $29.95bn mandatory. Of the mandatory money, $6.36bn is earmarked for Strategic and Critical Materials. When the document describes what that money is for, it names 18 minerals: arsenic, bismuth, gallium, germanium, graphite, hafnium, indium, magnesium, niobium, titanium, beryllium, cobalt, fluorspar, aluminium, tantalum, zirconium, rhodium and ruthenium. It adds five rare earths, terbium, samarium, gadolinium, yttrium and dysprosium. Antimony doesn't appear.

This should not be overstated. The list is prefaced with “includes, but is not limited to”, and it has no policy standing of its own. Nothing in it stops antimony projects being funded from that allocation. The $6.36bn is also the smallest of three critical minerals streams in the Pentagon's FY2027 mandatory request, which together total $48.7bn: $24.3bn for the Industrial Base Analysis and Sustainment programme and $18.0bn for the National Defense Stockpile sit alongside it, and the Pentagon says its minerals efforts cover more than 50 commodities. Still, when the Department of War described how it would spend the minerals allocation in its Defense Production Act request, it named 23 minerals and antimony didn't make the cut. That could indicate that it is further down the queue based on criticality. There are other possible explanations, and I will come to them in the conclusion.

It is also out of step with the import figures. The USGS estimates US net import reliance for antimony at 91 per cent in 2025, up from 86 per cent in 2024 and 81 per cent in each of the two years before. Domestic output didn't collapse; primary smelter production actually rose, from 588 to 700 tonnes. Imports simply grew much faster. Oxide imports went from 24,000 to 39,000 tonnes, and apparent consumption from 28,600 to 45,000 tonnes.

Apparent consumption is a measure of what entered the country rather than what was actually used, and some of that 2025 surge is likely to have been stockpiling after China's December 2024 export ban. The wider market has subsequently pulled back. Campine, which describes itself as the global market leader in antimony trioxide, said on 1 September that its trioxide volumes were down 23 per cent in the first half of 2026 on a yearly comparison, and attributed it to lower consumption, possibly through substitution, after last year's price spike. Part of the fall is also a base effect, because the comparison is with a period when buyers were likely stockpiling. Volumes in Campine's specialty chemicals division, which includes its trioxide business, rose 24 per cent in the first half of 2025, and the company has since described demand during that period as a surge.

The civilian and military markets for antimony behave very differently, and it helps to keep them separate. Flame retardants, which run on antimony trioxide, sit inside the USGS's largest use category, at 49 per cent of US consumption. Buyers there respond to price, as Campine's figures show. The military depends on a different compound, antimony trisulfide, which the Army puts in nearly 30 per cent of its ammunition items, mostly in primers. Qualified trisulfide for primers must meet a military specification and is not priced off any of the published market assessments.

Antimony has not been ignored by the Defense Production Act. Before this request, the same account had already awarded more than $100m to two antimony trisulfide projects. The first is Perpetua Resources' Stibnite Gold Project in Idaho, which will produce antimony alongside gold. Its $59.2m Title III agreement, issued through the Air Force Research Laboratory, has funded permitting and construction readiness; the project received final federal approval in 2025 and began early construction that October. The Stibnite Gold Project has drawn most of the money allocated overall. The largest sum is actually from outside the Pentagon: a $2.9bn Export-Import Bank loan to help build it, approved in May and still subject to final documentation. Perpetua also holds a separate $27.1m Army agreement, through the Defense Ordnance Technology Consortium, to prove that ore from the project can be refined into military-grade trisulfide; the pilot plant built under it opened at Idaho National Laboratory on 29 July.

The second is Nova Minerals. In October 2025 the Defense Production Act Purchases office awarded $43.4m to its US subsidiary to mine stibnite at its Estelle project in Alaska and refine it into military-grade trisulfide. The company is targeting first antimony production in 2027.

Other agencies have bought or backed antimony too. The Defense Logistics Agency gave US Antimony a five-year contract for stockpile ingots in September 2025, with a ceiling of $245m. The ingots are antimony metal, not primer-grade trisulfide. The first deliveries, about 82,000 pounds, went in this June, and the company states orders under the contract have reached $57.3m. And on 18 August the Department of Energy picked two antimony projects for award negotiations, worth up to $18m each: Felix Gold's Treasure Creek in Alaska, and Trigg Minerals' ASCEND-Sb, a smelting project. Being picked for negotiations does not guarantee receiving an award.

There may be simpler explanations for antimony's absence from this year's list. The first is that antimony has already been funded from the Defense Production Act Purchases account, possibly from an allocation other than minerals. Both awards described above were made before this request, the latest in October 2025, six months before the justification was published, and the document does not say which allocation paid for either. The same justification asks for $6.81bn for a Critical Chemicals Supply Chain allocation serving missiles and munitions, and trisulfide, as a primer ingredient, could plausibly sit there rather than among the minerals. If antimony is funded from the munitions or chemicals side, it would have no reason to appear in the minerals list at all.

The second is that the plan is still a work in progress. The $6.36bn is only a request, and an uncertain one: it depends on a reconciliation bill Congress has not passed, and the versions that House Republicans have put forward so far offer much less for defence than the $350bn the Pentagon asked for. The justification itself also warns that its figures are estimates and could change with market research, the acquisition process and other factors. The size of the increase suggests the same thing. The Strategic and Critical Materials allocation received $15m in FY2026 and about $257m the year before, and the new request is roughly 25 times the latter. Apart from the named minerals, the document is also vague about what the money will buy. It lists the stages of the supply chain it wants to support, from mining and processing through to smelting, refining and recycling, but it doesn't name a single project. It could be that the 23 minerals were simply the ones the department was ready to name in April.

There is a nearer hurdle too. Most of the Defense Production Act's authorities, including the Title III powers behind the awards described above, expire on 30 September, the day before FY2027 begins. Congress has let them lapse before: they expired on 30 September 2025 and were not restored until mid-November. In the meantime new awards stalled, including the Pentagon's planned equity stake in Trilogy Metals, which the company said could not close until the Act was reauthorised. The renewal that followed only ran the powers to this 30 September. A longer extension, to 2031, sits in the DPA Modernization Act of 2026, which has not passed. Unless Congress renews the Act in time, any FY2027 awards would have to wait until it does. We'll know more once Congress has renewed the Act and approved the funding, and the first awards come through.