AuKing Mining’s 49% Halls Creek joint venture now carries a three-metal development case with an estimated pre-tax NPV10 of about A$317 million. The figures remain preliminary, with Cobalt Blue targeting a Pre-Feasibility Study in the first half of 2028.
- A$317 million estimated pre-tax NPV10 and 47% IRR on a 100% project basis
- A$75 million initial capital estimate and approximately three-year payback
- Planned production of copper cathode, zinc oxide and silver doré over 11 years
- Cobalt Blue may lift its interest from 51% to 75% by funding a further A$1.5 million
- Pre-Feasibility Study targeted for completion in the first half of 2028
Halls Creek gains a third revenue stream
Silver has moved into the economic centre of AuKing Mining Limited’s (ASX:AKN) Halls Creek project, with an updated Scoping Study outlining a staged copper-zinc-silver development in Western Australia. The study, prepared by joint venture partner Cobalt Blue Holdings Limited (ASX:COB), estimates a pre-tax NPV10 of approximately A$317 million and a pre-tax IRR of about 47% on a 100% project basis.
The update incorporates silver recovery for the first time. On the study assumptions, a common processing plant at the Onedin deposit would produce copper cathode, zinc oxide and silver doré, with initial Onedin cash flow intended to support the subsequent development of Sandiego. The project is estimated to generate approximately A$681 million in life-of-mine free cash flow before tax.
A$75 million start-up case and 11-year production plan
Initial capital is estimated at A$75 million, while payback is forecast at approximately three years from first production. Average annual output is projected at about 4,000 tonnes of copper cathode, 13,000 tonnes of contained zinc as zinc oxide and 130,000 ounces of silver doré over an estimated 11-year production period.
The proposed design replaces the previously contemplated Sandiego flotation concentrator with shared infrastructure at Onedin. That configuration is presented as a way to recover three saleable metals through one plant and potentially accommodate additional regional feedstock, although any expansion in production, mine life or project economics remains a possibility rather than an established outcome.
Cobalt Blue can increase its project stake
Cobalt Blue currently holds 51% of Halls Creek, leaving AuKing with 49%. It has exercised a right to increase its interest to 75% by sole-funding a further A$1.5 million on the Halls Creek tenements by 30 June 2028. Cobalt Blue is also targeting completion of a Pre-Feasibility Study in the first half of 2028, setting a defined technical milestone for the project.
For AuKing, the arrangement preserves exposure to a potentially larger polymetallic development while its stated focus remains rare earths and niobium exploration in Malawi and Greenland. The company’s managing director, Paul Williams, said the study had improved the project’s development potential and described the separate silver product as encouraging.
Scoping Study economics remain preliminary
The headline valuation and production figures come from Cobalt Blue’s updated Scoping Study and remain subject to the cautionary statement attached to that announcement. AuKing said it was not aware of new information that materially affects those figures or of material changes to the assumptions and technical parameters underpinning them. The next test will be whether further technical and metallurgical work can support the study’s capital, recovery, production and payback assumptions as the project moves towards pre-feasibility.
Bottom Line?
The silver addition improves the project narrative, but the key value test now shifts to whether the A$75 million capital case survives more detailed engineering and a change in joint venture ownership.
Questions in the middle?
- Can the shared Onedin processing route deliver the projected recovery of copper, zinc and silver at the stated capital cost?
- How will Cobalt Blue’s potential increase to a 75% interest affect AuKing’s future funding obligations and project exposure?
- Will the Pre-Feasibility Study in the first half of 2028 preserve the Scoping Study’s three-year payback and A$317 million pre-tax NPV10?