Antimony

What Is Antimony

Antimony is element 51 — a silvery-white metalloid (a material with properties between a metal and a non-metal, its symbol Sb derived from the Latin stibium) that has been mined and used for over 5,000 years. Ancient Egyptians used it in cosmetics. Medieval alchemists called it the wolf of metals. Today it is one of the most consequential materials in modern industrial infrastructure, and almost nobody outside the supply chain knows its name.

Antimony's strategic importance comes from what its compounds do rather than what the metal itself is. Antimony trioxide (Sb₂O₃ — the most widely traded antimony compound, produced by oxidising antimony metal) is the dominant synergist in halogenated flame retardant systems — meaning it dramatically amplifies the fire-suppressing effect of other chemicals used in plastics, electronics casings, textiles, building materials, and cables. Approximately 50% of all global antimony demand goes into flame retardants. There is no cost-effective substitute at scale. Regulatory approvals for alternatives take a minimum of six months and significant capital investment — meaning substitution cannot happen quickly even when buyers want it to.

Beyond flame retardants: antimony alloys with lead to harden the plates in lead-acid batteries (the batteries that start every internal combustion vehicle, power forklifts and backup generators, and store energy in off-grid solar systems). Sodium antimonate is used as a glass clarifier in photovoltaic solar glass — improving light transmission and therefore panel efficiency. Antimony compounds are essential to ammunition primers, tracer rounds, and military pyrotechnics. And antimony is used in infrared detectors, night-vision optics, and specialty semiconductors.

The breadth is the point. This is not a metal with one critical application that could theoretically be substituted around. It is woven through fire safety, energy storage, solar energy, defense, and semiconductors simultaneously. When China restricted exports in 2024, all of those applications felt it at the same time.

Where It Comes From

China accounts for approximately 48–50% of global antimony mine production and a significantly higher share of refined antimony product supply — particularly for the high-purity grades required by defense, semiconductor, and solar applications. Unlike some critical minerals where China's dominance is even more extreme, antimony has meaningful production outside China: Russia (third-largest globally, now largely cut off from Western markets due to sanctions), Tajikistan, Myanmar (significant but politically unstable), Bolivia, and Turkey. Total global annual production runs approximately 80,000–90,000 tonnes.

The concentration problem is not just mining — it is refining. High-purity antimony processing for defense and semiconductor applications is dominated by Chinese facilities. Even where ore exists outside China, the processing infrastructure to produce defense-grade antimony metal at scale does not.

The United States has zero domestic antimony production. The last US antimony mine closed in 2001. The US is 100% import dependent, with China historically supplying more than half of US demand until export controls disrupted those flows.

The most significant development in Western antimony supply in decades: on May 21, 2026, the US Export-Import Bank board unanimously approved a $2.9 billion senior secured loan — its fourth largest loan on record and the largest under its Make More in America initiative — to fund Perpetua Resources' Stibnite Gold Project in central Idaho. The loan is structured as a 13-year credit facility with a $2.4 billion upfront tranche; definitive documentation is expected in the second half of 2026, with first disbursement contingent on satisfying conditions precedent. Stibnite holds an estimated 148 million pounds of antimony reserve — the only identified antimony reserve in the United States and one of the largest outside Chinese control. Construction has begun. Production is expected in 2029. At initial production, Stibnite is designed to supply approximately 35% of US antimony demand. The EXIM loan, combined with cash on hand, is expected to cover full estimated construction costs — the risk is not whether it gets built. The risk is the three years between now and when it produces.

United States Antimony Corporation (NYSE American: UAMY) operates North America's only two antimony smelters and holds a sole-source contract with the US Defense Logistics Agency worth approximately $245 million over five years to supply antimony metal ingots to replenish the National Defense Stockpile. The first delivery order of approximately $10 million was placed in September 2025.

Why It Matters Right Now

The well-known driver is the Chinese export ban — licensing controls imposed September 2024, escalated to an outright ban on antimony exports to the United States in December 2024, then suspended through November 27, 2026 as part of broader US-China trade negotiations covering gallium and germanium simultaneously.

The underappreciated driver is where antimony sits in the energy transition — and almost no critical minerals coverage is connecting these dots.

Photovoltaic solar glass — the glass used in solar panels — uses sodium antimonate (a refined antimony compound) as a clarifying and fining agent that reduces melting temperatures, removes bubbles, and improves light transmission. More light transmission means higher panel efficiency. Antimony demand from the photovoltaic sector was forecast to reach 68,000 tonnes in 2026, up from 16,000 tonnes in 2021 — a fourfold increase in five years. Solar PV is expected to account for more than a third of all non-metallurgical antimony demand by 2030.

The collision is direct. China is simultaneously the world's dominant antimony producer and the world's dominant solar panel manufacturer. China's export controls restrict the supply of a material that its own solar industry consumes in quantity — while the West, building out solar capacity, faces constrained access to the same material. The solar buildout and the defense supply crisis are drawing on the same constrained resource from the same constrained supplier.

Wire and cable for data centers adds a third demand stream. Flame-retardant PVC (polyvinyl chloride — the plastic used in cable insulation) uses antimony trioxide as a synergist. Every data center being built right now requires flame-retardant cable. Every kilometer of that cable contains antimony. There is no direct substitute that has passed regulatory approval at scale.

The Adequate Supply Illusion

Here is the contradiction the antimony market is currently presenting: prices peaked at $59,750 per tonne in July 2025 — a level that should have triggered a massive supply response. It didn't. Prices have since corrected to approximately $34,000–51,800 per tonne depending on grade and geography. Market commentary for 2026 describes adequate supply. That sounds like resolution. It is not.

The adequacy is temporary and conditional. China suspended the US export ban in November 2025. Southeast Asian smelting capacity in Vietnam and Thailand partially filled gaps for lower-grade material. The acute shortage of mid-2025 has eased. But the structural conditions that created the shortage have not changed: China still controls 50% of mine supply and a higher share of refining. The November 27, 2026 expiration of the suspension is eight months away — the same countdown running simultaneously on gallium and germanium. Russian supply remains blocked by sanctions. Myanmar supply is politically unstable. Non-Chinese refining capacity for high-purity defense-grade antimony remains minimal.

The $59,750 per tonne peak did not unlock new supply because antimony supply cannot be unlocked quickly. It is a byproduct of lead, gold, and copper mining in many cases — not a standalone commodity that responds to price signals with new mine development. Where dedicated antimony deposits exist, permitting and construction timelines are measured in years, not months. Stibnite took eight years of permitting before breaking ground. It will not produce until 2029.

The adequate supply of 2026 is a temporary window created by a policy suspension that expires in November, drawing on Southeast Asian capacity that covers lower-grade industrial demand but not defense-grade requirements. When the suspension expires, the structural shortage returns — against a demand picture that has grown because solar, data centers, and defense procurement have all added incremental consumption during the window.

What the Price Has Done

Before 2024, antimony was an overlooked byproduct metal priced like one — $15,000–18,000 per tonne, stable, reflecting steady demand from flame retardants and lead-acid batteries with no particular supply narrative. Decades of Chinese production dominance kept prices contained and Western mine development economically impossible.

August 2024 changed that. China announced export licensing controls on antimony effective September 2024. The immediate market reaction was sharp: prices surged from approximately $21,600 per tonne in August toward $39,900 per tonne by December — a near-doubling in four months as buyers competed for available non-Chinese inventory and built precautionary stockpiles.

December 3, 2024 escalated further. China imposed an outright ban on antimony exports to the United States specifically — the same date as the gallium and germanium bans, coordinated retaliation for new US semiconductor export restrictions. European prices hit $39,500–40,000 per tonne at Rotterdam by year end.

The first half of 2025 brought the full impact. Global prices jumped approximately 24% in Q2 alone. North America became the world's most expensive antimony market as US buyers scrambled for third-country supply routed through Thailand, Belgium, and Mexico. On July 4, 2025, Fastmarkets recorded the all-time historical high of $59,750 per tonne — a nearly fourfold increase from pre-restriction levels in under twelve months.

November 9, 2025: China suspended the US-specific ban through November 27, 2026 alongside gallium and germanium. Licensed material began flowing again. Southeast Asian capacity filled some lower-grade gaps. Prices corrected — to approximately $44,700 per tonne in November, then stabilising at a global average of approximately $34,830 per tonne through Q1 2026.

May 2026: Western retail stands at approximately $51,800 per tonne. SMM domestic China sits at approximately $23,700 per tonne converted. The market is down approximately 5.85% year to date and described as stable. The 2x gap between domestic Chinese pricing and Western retail reflects the same structural dynamic as gallium and germanium — export controls mean domestic Chinese supply cannot freely reach Western buyers regardless of relative price.