ASX-listed Felix Gold has reported strong metallurgical results from its Treasure Creek antimony project, in the US, highlighting the potential for simplified ore-to-metal processing routes and positioning the asset as a potential contributor to Western critical minerals supply chains.

The company reported on Thursday that testwork across multiple independent programmes confirmed that high-grade material from Treasure Creek could be processed via both pyrometallurgical and hydrometallurgical pathways, with minimal pre-treatment.

A 370 kg bulk sample of hand-sorted stibnite ore, extracted during field trials, exceeded US military concentrate specifications, confirming the presence of direct shipping ore (DSO) of exceptional quality.

Executive director Joseph Webb said the results underscored the uniqueness of the deposit.

“This is not concentrate – this is ore: direct shipping ore that meets military-grade specifications,” he said.

Felix noted that the sample surpassed the US Military Concentrate Specification (MIL-A-22131), with the company stating that no known Western sources currently produce antimony concentrate meeting this threshold.

Metallurgical testwork by Core Resources demonstrated that untreated ore could be directly smelted into antimony metal, validating a simplified processing flowsheet. Parallel hydrometallurgical testwork by Blue Coast Research achieved antimony extraction rates of up to 98% through alkaline sulfide leaching, with more than 90% recovered within the first two hours.

Further downstream processing at the University of British Columbia successfully produced high-purity antimony metal through electrowinning, confirming an alternative ore-to-metal pathway.

Core Resources also reported overall antimony recoveries of about 99% at relatively coarse grind sizes of 150 μm to 300 μm, supporting the potential for lower processing intensity and reduced operating complexity.

Felix said the combination of high-grade ore and simplified processing could enable a smaller project footprint, reduced waste and shorter development timelines compared with conventional antimony operations.

In parallel, engineering group Worley has completed a US-based processing study, including site selection and evaluation of toll treatment and standalone processing options, as the company assesses pathways to commercialisation.

The latest results follow recent regulatory approval to extract bulk ore samples from Treasure Creek, with Felix now evaluating development options in a policy environment increasingly focused on establishing domestic US supply chains for critical minerals.