In a world increasingly shaped by geopolitical tensions, clean energy transitions, and supply chain fragility, the hunt for critical minerals is intensifying. While lithium, copper, and rare earths have dominated headlines, a lesser-known metal—antimony—is quietly stepping into the spotlight. For investors evaluating resource companies, antimony’s unique characteristics and strategic importance are impossible to ignore.
What Is Antimony?
With chemical symbol: Sb, it is a brittle metalloid used in a variety of industrial, military, and clean-tech applications. It is typically found in nature combined with sulfur, most commonly as the mineral stibnite (Sb₂S₃). Stibnite (Sb₂S₃), the main antimony ore, frequently occurs alongside visible gold, especially in regions with volcanic or sedimentary host rocks.
While it has ancient uses in cosmetics and metallurgy, modern Sb demand is driven by three core areas: flame retardants, lead-acid batteries, and increasingly, advanced energy storage and military technologies.
Despite its broad utility, global production is heavily concentrated—over 70% of the world’s supply comes from China, a fact that has caught the attention of Western policymakers.
Why Antimony Matters: Strategic Metal Status
Antimony is now classified as a critical mineral by the United States, the European Union, Australia, and other jurisdictions. The U.S. Department of Defence has identified it as essential to national security and energy infrastructure. The metal’s utility in armour-piercing ammunition, semiconductors, and thermal batteries places it firmly in the strategic resources category.
This classification has several consequences:
- Government stockpiling: The U.S. National Defence Stockpile includes antimony reserves.
- Grant eligibility: Exploration and development projects may receive support under critical mineral funding programs in the U.S., Canada, and Australia.
- Fast-tracked approvals: Mines focused on critical minerals may be prioritized in permitting processes.
Key Applications Driving Demand
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Flame Retardants (50% of demand)
Antimony trioxide is widely used as a synergist in halogenated flame retardants, essential in plastics, textiles, and electronics. Regulations mandating flame resistance in building materials and electronics ensure steady demand. -
Lead-Acid Batteries (30%)
Sb strengthens the plates inside traditional batteries used in vehicles and industrial backup systems. Though lithium-ion batteries are surging, lead-acid technology remains irreplaceable in many settings. -
Energy and Military Tech
Antimony alloys improve battery performance in liquid metal batteries, a promising grid-scale storage solution. In military applications, it’s used in infrared detectors, armour plating, and munition. -
Semiconductors and Pharmaceuticals
Antimony-based compounds like indium antimonide are used in semiconductors and infrared sensors. Some uses are also emerging in antimicrobial agents and cancer treatments.
Global Supply Chain: A Geopolitical Risk
The Sb supply chain is concentrated:
- China dominates mining and refining.
- Russia, Tajikistan, and Bolivia are secondary producers.
- No significant production in the U.S. or Canada, making downstream industries vulnerable to export restrictions.
China’s track record of restricting exports of strategic metals (such as rare earths and graphite) raises alarm bells. If Beijing were to impose quotas or tariffs on antimony, as it has with some rare earth elements, Western manufacturing and defence sectors could face serious disruptions.
This backdrop has led to increased exploration in stable jurisdictions, particularly Australia, Canada, and the U.S., with investors eyeing companies that can fill the looming supply gap.
Five ASX Companies with Antimony Projects
1. Larvotto Resources (ASX LRV)
- Project: Hillgrove Project, New South Wales
- Highlights: Hosts Australia’s largest antimony deposit and the 8th largest globally, with a Mineral Resource Estimate of 1.7 million oz AuEq at 7.4 g/t AuEq. A Pre-Feasibility Study released in August 2024 outlines plans for annual production exceeding 80,000 oz AuEq.
2. Trigg Minerals (ASX TMG)
- Projects: Achilles, Taylors Arm, and Spartan Projects, New South Wales
- Trigg Secures High-Grade Antimony Canyon Claim Block in Utah – Stock Surge (updated: 19 May, 2025)
- Highlights: The Achilles Project’s Wild Cattle Creek deposit contains 1.52 Mt at 1.97% Sb (~30,000 tonnes), representing Australia’s highest-grade undeveloped primary resource.
3. Nagambie Resources (ASX NAG)
- Projects: Nagambie Mine and surrounding tenements in Victoria
- Highlights: Holds a 1,000 sq km tenement package targeting high-grade gold-antimony mineralization. Recent reports indicate a maiden resource with 17.8 kt of contained Sb.
4. Southern Cross Gold (ASX SXG)
- Project: Sunday Creek Project, Victoria
- Highlights: Recent drilling intersected a 135m-wide gold-antimony zone, with assays up to 31.5% antimony. The company has arranged C$143 million in funding to accelerate project development.
5. Iltani Resources (ASX ILT)
- Project: Antimony Reward Deposit within the Herberton Project, Queensland
- Highlights: Follow-up exploration confirmed high-grade antimony mineralization, with assays up to 17.3% Sb.
Pricing and Market Dynamics
Antimony prices are notoriously volatile, ranging from US$5,000 to US$12,000 per metric ton over the past decade. Current spot prices (as of May 2025) hover around US$28,000, boosted by supply concerns and increased military stockpiling. Up to date prices of various antimony compounds and ores can be found here.
Unlike metals traded on major exchanges like copper or nickel, antimony pricing is opaque. It relies on negotiated contracts and benchmark prices published by agencies like Argus and Fastmarkets. This makes due diligence and company guidance especially critical for investors.
Investment Risks and Considerations
Investors exploring antimony exposure should weigh:
- Jurisdiction risk: Projects in politically stable, mining-friendly regions like Australia or Canada are preferable.
- Processing capability: Antimony requires specialized metallurgy; companies without off-take agreements or refining partnerships may struggle.
- Environmental concerns: Antimony is toxic in certain forms, and improper handling can lead to regulatory backlash.
- By-product economics: Most antimony is produced as a by-product of gold or silver mining; standalone antimony projects are rare and must prove economic viability.
Antimony may not have the hype of lithium or the lustre of gold, but its strategic relevance, supply risk, and growing technological role make it an interesting space for forward-looking investors.
