Key Highlights

  • Felix Gold designed, built and operated a pilot plant that demonstrated the complete process flowsheet for its proposed US antimony refinery end-to-end.
  • Ore was smelted and fumed to antimony trioxide, with the fume captured, reduced and cast to metal ingot, confirming every unit operation performed as designed.
  • Direct-smelt processing was confirmed, with ore charged straight to the furnace from hand-sorting and coarse crushing, eliminating the need for a concentrator stage.
  • The program supports the company's recent selection for up to US$18 million in funding from the US Department of Energy.

Felix Gold Limited (ASX:FXG) share price was trading at $0.24, up 4.44% or $0.010 on the day, as at 27 August 2026, 12:17pm AEST, following the announcement that the design flowsheet for its Frontier Antimony Refinery was built, operated and demonstrated end-to-end under pilot plant conditions, de-risking the company's US refining pathway. The company designed, constructed and operated a pilot plant replicating the process flowsheet for Frontier's proposed US refinery and produced antimony metal from Treasure Creek ore.

The complete process route was demonstrated, with ore smelted and fumed to antimony trioxide, the fume captured and reduced, and antimony metal cast to ingot, with each unit operation in the design flowsheet performing as designed. The program was designed and supervised by MetaMets and conducted at an independent third-party metallurgical facility, operated in batch mode on bench and demonstration-scale equipment.

Direct-Smelt Route Confirmed, Shortening the Flowsheet

A key outcome of the program was confirmation that ore could be charged to the furnace directly from hand-sorting and coarse crushing, with no grinding, flotation or concentrate stage required. The company said this represents a materially shorter flowsheet than conventional antimony projects typically require, a function of ore quality rather than engineering design choice.

The company said the technical pathway has now been de-risked, eliminating unknowns from the principal process ahead of refinery feasibility and confirming the design basis for the engineering work now underway. The flux behaviour, fume capture, briquetted feed handling and contamination pathways observed during the program feed directly into this ongoing engineering work.

Frontier Antimony Refinery Structure and Purpose

Frontier Antimony Refinery Corp is Felix Gold's 100%-owned, Delaware-incorporated subsidiary, structured to convert US ore into US metal, addressing what the company describes as the United States' lack of a meaningful domestic primary antimony Supply chain. Felix Gold holds bulk sample permitted, high-grade antimony ore at Treasure Creek, with Frontier structured as the vehicle through which that ore is to be refined and sold into the US market.

Frontier's current position includes ore feed secured from Treasure Creek, a completed US site-selection study prepared by Worley/SLR with evaluation now narrowed to specific priority locations, substantially advanced preliminary engineering design for the refinery, and the demonstrated process route that is the subject of this announcement. The company said feasibility work cannot be finalised, and no Capital or operating cost estimates can be released, until a final US site is selected and site-specific inputs are incorporated.

Relationship to Department of Energy Funding Selection

As announced on 19 August 2026, the US Department of Energy selected the Treasure Creek Antimony Pilot Processing Facility for negotiation of a financial award of up to US$18 million, under funding opportunity DE-FOA-0003583, with a proposed company cost share of 26.8% to be provided in kind through delivery of ore. The applicant for this funding was Felix Gold Alaska Treasure Creek Inc, the company's wholly-owned US subsidiary, with the selection not sitting within the Frontier structure.

Any DOE funding obligated on completion of award negotiations is intended to be applied toward the capital cost of the Frontier refining facility, though the company noted that funding has not been obligated, the funded scope remains subject to negotiation, and application of funding within the group is subject to DOE approval. Felix Gold was selected under Topic Area 2b, which covers projects with previously developed pilot-scale facilities directed at advancing those processes from prototype to pre-commercial demonstration, with the pilot program reported in this announcement underpinning that classification.

Conclusion

Felix Gold's demonstration of its complete antimony refining flowsheet, from ore through to cast metal ingot, represents a material technical milestone that removes process-level uncertainty ahead of formal refinery feasibility work. The confirmation of a direct-smelt route without a concentrator stage offers a materially shorter and potentially lower-capital pathway than conventional antimony projects, while the program's alignment with the company's Topic Area 2b selection under the Department of Energy's funding opportunity provides a link between this technical progress and the up to US$18 million funding award currently under negotiation, with feasibility work still pending final US site selection.