Antipa Minerals ASX:AZY has confirmed a conventional gold-copper processing route for its 100%-owned Minyari Dome development project in Western Australia’s Paterson Province after completing key pre-feasibility study (PFS) metallurgical test work and geotechnical programs.

The results delivered gold recoveries of 89% to 98% across oxide, transitional and primary material types, rapid leach kinetics, and the potential to produce both gold doré and a separate commercial-grade copper concentrate.

Updated geotechnical parameters have also strengthened open-pit development optionality by supporting steeper overall slope angles in transitional and primary mineralisation zones than those used in the previous scoping study.

Minyari Dome forms the core of Antipa’s broader Minyari project, currently hosting a gold mineral resource of 2.5 million ounces at 1.5 grams per tonne, along with copper, silver, and cobalt.

Conventional Processing Route

The PFS metallurgical work found the gold mineralisation to be free-milling and non-refractory, with primary material supporting a conventional CIL production pathway.

Antipa confirmed the most likely processing pathway for Minyari would comprise carbon-in-leach (CIL) gold doré production, followed by the option of flotation of CIL residue to produce a separate copper concentrate.

Gold recoveries ranged from 93.3% to 97.8% in oxide material, 94.9% to 97.6% in transitional material, and 89% to 90% in primary fresh material.

Flotation of primary CIL residue produced a separate copper concentrate grading approximately 22% copper, while arsenic levels in the concentrate remained below typical smelter penalty limits.

Open-Pit Optionality

Antipa’s geotechnical work comprised 32 diamond drill holes for 6,918.9 metres including open-pit wall drilling, logging, sampling, laboratory testing, structural and kinematic analysis, and stability modelling.

The resulting PFS-level design parameters support steeper open-pit slope angles for transitional and primary material than those assumed in the scoping study.

Updated parameters include a transitional overall slope angle of 41.2% compared with 37% in the scoping study, and a primary overall slope angle of 51.3% down to 250m below surface compared with 50% previously.

Antipa expects the revised parameters to inform mine design and optimisation, including an assessment of deeper open pit mining and a potential reduction or removal of underground mining from the development schedule.

The company expects to complete technical PFS workstreams in the third quarter of this year and release PFS outcomes shortly afterwards, while a range of definitive feasibility study (DFS) activities are already under way.

Minyari Potential Reaffirmed

Chief executive officer Roger Mason said the new results strengthened Minyari’s technical foundation.

“The outcomes reported today strongly reaffirm the potential of the Minyari development, […] and provide a clearer view of the Project’s optimal processing and development pathway,” he said.

“PFS-level metallurgical test-work has confirmed that Minyari mineralisation is amenable to a conventional processing flowsheet, delivering strong gold recoveries alongside the potential to produce both gold doré and a separate commercial-grade copper concentrate.”

On the mining side, updated geotechnical parameters […] provide an important input into the pit optimisation, including the evaluation of deeper open-pit mining and the potential to reduce, or remove, underground mining from the initial mine plan.”

We remain on track to complete the technical PFS workstreams in Q3 CY2026, with PFS outcomes to follow shortly thereafter, while DFS-level activities are ramping up.”