Astral Resources NL (ASX:AAR) has completed a compelling Pre-Feasibility Study (PFS) for its 100%-owned Mandilla Gold Project, near Kalgoorlie in Western Australia, projecting strong long-term returns and confirming development viability.
The PFS outlines a production target of 1.41 million ounces over a 19-year mine life, including 13 years of open-pit mining. At a base case gold price of A$4,250 per ounce, the project is forecast to generate A$2.8 billion in pre-tax free cashflow and a net present value (NPV8) of around A$1.4 billion. A higher price scenario of A$5,000/oz lifts free cashflow to A$3.9 billion and NPV8 to A$2 billion.
Stage 1 (first 12 years) production is expected to average 95,000 ounces of gold annually at 1.13 grams per tonne (g/t), transitioning to stockpile treatment in Stage 2 with 42,000 ounces per annum at 0.50 g/t. A 2.75 million tonnes per annum (Mtpa) carbon-in-pulp (CIP) plant will underpin the operation, with recoveries averaging 95.5%.
Astral also declared a maiden Probable Ore Reserve Estimate of 36.6 million tonnes at 0.9 g/t Au for 1.08 million ounces, inclusive of the Mandilla and Feysville deposits.
Key physicals assumptions.
LOM financial forecast summary.
“The Pre-Feasibility Study confirms Mandilla as a compelling gold development opportunity in a tier one mining jurisdiction,” managing director Marc Ducler said.
“The PFS demonstrates the potential for Mandilla to be a long-term, high margin project, with a life of mine production target of approximately 1.4 million ounces at an all in sustaining cost of approximately $2,085 per ounce over an almost 19-year project life, underpinned by a maiden gold ore reserve of approximately 1.1 million ounces.
“At a gold price assumption of A$4,250, the project generates life-of-mine pre-tax free cash flow of over $2.8 billion, an average of more than $150 million per annum. At a gold price of A$5,000, the life-of- mine pre-tax free cash flow jumps to $3.9 billion, an average of over $200 million per annum.”
Project overview
Astral’s Mandilla Gold Project hosts a Mineral Resource of 42 million tonnes (Mt) at 1.1 g/t gold (Au) for approximately 1.43 million ounces (Moz) of contained gold. This includes the Theia, Iris, Hestia and Eos deposits. An Ore Reserve of 34.3 Mt at 0.9 g/t Au supports approximately 1 Moz of contained gold, as outlined in section 4.1.4 of the Pre-Feasibility Study (PFS).
Map illustrating the location of the Mandilla, Feysville and Spargoville Projects.
The PFS also integrates resources from the nearby Feysville Project, situated within the Norseman–Wiluna Greenstone Belt of the Archean Yilgarn Craton, roughly 14 kilometres south of Kalgoorlie’s Super Pit. Feysville comprises the Kamperman, Think Big and Rogan Josh deposits and hosts a Mineral Resource of 5 Mt at 1.2 g/t Au for 196,000 ounces of contained gold. It also includes an Ore Reserve of 2.3 Mt at 1.2 g/t Au for approximately 88,000 ounces, referenced in section 4.2.4 of the PFS.
Astral's May 2025 acquisition of Maximus Resources Ltd delivered 100% ownership of the Spargoville Project, adding approximately 144 square kilometres of mainly contiguous tenure adjacent to Mandilla. Spargoville holds a Mineral Resource of 3 Mt at 1.4 g/t Au for approximately 139,000 ounces of contained gold across the Wattle Dam, Eagles Nest, Larkinville, Hilditch and 5B deposits. While the PFS does not incorporate Spargoville ore into production schedules, the area is earmarked for infrastructure and operational support.
Astral will now advance Mandilla to a Definitive Feasibility Study (DFS) to further refine development plans.
“Given the outstanding economic outcomes of this PFS, Astral is now firmly on the pathway to its goal of becoming a significant Kalgoorlie gold producer. Astral is targeting completion of a Definitive Feasibility Study in June 2026," Ducler said,
“In parallel with the DFS, Astral will work on converting more Inferred Mineral Resources to Indicated while also targeting resource growth exploration at its Mandilla, Feysville and Spargoville Projects. It is well worth noting that, despite currently having a gold resource of approximately 139,000 ounces, the PFS does not currently contemplate any ore being sourced from the Spargoville Project recently added as part of our Maximus acquisition.”
PFS highlights
Astral has confirmed the development of a 2.75 Mtpa CIP processing facility and associated infrastructure as the optimal commercialisation strategy for its Mandilla Gold Project. The CIP flow sheet is projected to achieve an average gold recovery of 95.5%.
The PFS forecasts an initial 13-year mining period feeding into a 19-year life-of-mine (LoM) production schedule, delivering significant economic returns based on a conservative gold price assumption.
Production target highlights long-life, two-stage gold output profile
Astral Resources forecasts total recovered gold production of approximately 1.41 million ounces over the life of the Mandilla Gold Project.
Around 80% of the Mineral Resources scheduled for extraction are classified as Indicated, providing a high level of confidence in the project's capacity to repay pre-development capital from early-stage revenues. The remaining 20% are classified as Inferred.
The production schedule is structured over two key phases:
1. Stage 1 – Higher grade production (Years 1–12):
Gold output is projected to average approximately 95,000 ounces per annum at an average grade of 1.13 grams per tonne gold (g/t Au) during the initial 12 years of operation.
2. Stage 2 – Stockpile processing (Years 13–19):
Over the remaining 6.5 years of the life-of-mine (LoM), the project will process lower-grade stockpiles, yielding an average of approximately 42,000 ounces per annum at a grade of 0.50 g/t Au.
Detailed breakdowns of annual payable gold by Resource category and processing throughput profiles are provided in Charts 1 and 2 respectively.
Chart 1– Tonnes material processed by Mineral Resource category.
Chart 2 – Annual processing throughput.
Production profile
Total life-of-mine production: ~1.41 million ounces (oz) of gold over 19 years
Stage 1 (Years 1–12):
- Average production: ~95,000 oz/year
- Average grade: 1.13 grams per tonne (g/t) gold
Stage 2 (Years 13–19):
- Average production: ~42,000 oz/year
- Average grade: 0.50 g/t gold (lower-grade stockpiles)
Cost structure (LoM AISC: ~A$2,085/oz)
- Mining: ~A$1,098/oz
- Processing: ~A$681/oz
- General and administrative: ~A$118/oz
Capital requirements
Total pre-production capital and working capital: ~A$227 million
- Processing plant and infrastructure: ~A$180 million
- Pre-production mining and other costs: ~A$47 million
Financial metrics (A$4,250/oz gold price)
- Revenue: ~A$6.0 billion
- Pre-tax, undiscounted free cash flow: ~A$2.8 billion
- Cumulative EBITDA: ~A$3.1 billion
- Pre-tax NPV8: ~A$1.4 billion
- Pre-tax IRR: ~101%
- Payback period: <1 year
Upside scenario (A$5,000/oz gold price)
- Revenue: ~A$7.1 billion
- Pre-tax, undiscounted free cash flow: ~A$3.9 billion
- Cumulative EBITDA: ~A$4.2 billion
- Pre-tax NPV8: ~A$2.0 billion
- Pre-tax IRR: ~136%
- Payback period: 9 months
Reserve base
- Maiden Probable Ore Reserve: 36.6 million tonnes at 0.9 g/t for ~1.1 million oz
- Mandilla: 34.3 million tonnes at 0.9 g/t for ~1.00 million oz
- Feysville: 2.3 million tonnes at 1.2 g/t for ~88,000 oz
The PFS was completed with input from leading independent consultants, including Como Engineers, Cube Consulting, Entech Mining, and others. The study confirms Mandilla’s potential as a long-life, low-risk development opportunity underpinned by robust economics and expansion optionality.