West Cobar Metals has confirmed that antimony grades at its Bulla Park project in NSW are higher than previously reported, thanks to a new assay method. This discovery could enhance the deposit’s value amid rising demand for critical minerals.
- New peroxide fusion assay reveals 6-14% higher antimony grades
- Bulla Park holds 20Mt inferred resource with significant copper, antimony, and silver content
- Exploration target expanded to 30-50Mt with promising upside potential
- Metallurgical testwork shows strong recoveries for copper, antimony, and silver
- Further assay results expected in Q2 2026 to refine resource estimates
Reassessing Bulla Park’s Antimony Potential
West Cobar Metals Limited (ASX – WC1) has announced a significant update to the antimony grades at its Bulla Park Copper-Antimony-Silver deposit in central New South Wales. Using a more precise peroxide fusion digestion assay, the company found that previous four-acid digest methods had under-reported antimony concentrations by an average of 6 to 14 percent. This revelation suggests the deposit contains more antimony than initially estimated, a critical mineral increasingly sought after in global markets.
Resource and Exploration Upside
The Bulla Park deposit currently hosts an inferred mineral resource of 20 million tonnes at 0.58% copper equivalent, which includes approximately 60,000 tonnes of copper, 20,000 tonnes of antimony, and 3 million ounces of silver. Importantly, the mineralisation remains open along strike and at depth, with an exploration target ranging between 30 and 50 million tonnes. This target, while conceptual, is supported by geophysical data and historical drilling, indicating substantial potential to expand the resource base.
Metallurgical Advances and Product Streams
Complementing the grade upgrade, metallurgical testwork has demonstrated robust recoveries of 94.6% copper, 82.6% antimony, and 84.1% silver through flotation and selective leaching processes. These results underpin the feasibility of producing two distinct saleable products – a clean copper-silver concentrate and a high-grade antimony sulphide precipitate. Such dual-product potential enhances the project’s economic attractiveness and aligns well with market demand for critical minerals.
Strategic Importance Amid Global Critical Minerals Focus
Bulla Park’s upgraded antimony grades come at a time of heightened geopolitical focus on critical minerals. Both the Australian and U.S. governments have launched initiatives to secure supply chains for minerals like antimony, rare earths, and gallium. West Cobar is actively engaging with advisory firms and government programs to position its projects, including Bulla Park and the Salazar Critical Mineral Project in Western Australia, to benefit from these strategic priorities.
Next Steps and Market Implications
The company is currently reanalysing remaining historical drill core samples using the peroxide fusion method, with results expected in the second quarter of 2026. These updated assays will feed into the next resource upgrade, potentially further enhancing the deposit’s grade and size. For investors and analysts, the evolving understanding of Bulla Park’s antimony content could translate into improved project economics and a stronger market position amid rising demand for critical minerals.
Bottom Line?
West Cobar’s refined antimony grades at Bulla Park could reshape the project’s value proposition as critical mineral demand intensifies.
Questions in the middle?
- Will the forthcoming assay results confirm a sustained increase in antimony grades across the deposit?
- How might the higher antimony content influence the economics and development timeline of Bulla Park?
- What impact will government critical mineral initiatives have on funding and advancing West Cobar’s projects?