Austral Gold has unveiled a comprehensive 14-year life-of-mine plan for its Guanaco Mine in Chile, underpinned by a US$192.1 million after-tax NPV and robust mineral reserves.
- 14-year mine life with open-pit mining
- Proven and Probable Reserves: 18.1 Mt at 0.84 g/t Au
- After-tax NPV10% of US$192.1 million
- LOM metallurgical recoveries: 72% gold, 47% silver
- Pending environmental permits for key areas
Life-of-Mine Plan Extends to 2040 with Established Infrastructure
Austral Gold Limited (ASX:AGD) has released an updated Technical Report for its Guanaco Mine in Chile, revealing a 14-year mine life stretching from January 2026 to February 2040. The plan is anchored on proven open-pit mining and the reprocessing of existing heap leach pads, leveraging the mine’s established processing facilities and infrastructure.
The Proven and Probable Mineral Reserves stand at 18.1 million tonnes grading 0.84 grams per tonne gold and 5.43 grams per tonne silver. This translates to approximately 352,000 ounces of gold and 1.493 million ounces of silver, calculated at conservative metal prices of US$2,200 per ounce gold and US$25 per ounce silver.
Economic Valuation Highlights Robust Project Fundamentals
The after-tax net present value (NPV) at a 10% discount rate is estimated at US$192.1 million, with an undiscounted pre-tax free cash flow of US$379.4 million. The life-of-mine economic model uses average metal prices of US$3,135 per ounce gold and US$42 per ounce silver, based on a median consensus forecast. Operating costs are competitive, with an all-in sustaining cost (AISC) of US$2,114 per gold-equivalent ounce and an average operating cost (C1) of US$1,978 per gold-equivalent ounce.
Capital expenditure requirements are modest at US$13.9 million over the mine life, primarily focused on sustaining capital and closure costs. The mine benefits from a low capital intensity approach by utilising existing permitted processing facilities, reducing execution risk and allowing capital to be concentrated on value-generating mining activities.
Metallurgical Recoveries and Processing Routes Confirmed
Metallurgical recoveries average 72% for gold and 47% for silver over the life of mine, blending heap leach and agitation leach processing. The heap leach circuit reprocesses legacy heap materials, while fresh ore from the Dumbo, Defensa, Perseverancia, Quillota, and Inesperada open pits is processed through an agitated leach plant. Recent metallurgical test work, including high-pressure grinding roll (HPGR) crushing, supports the recovery assumptions underpinning the mine plan.
Environmental and Permitting Status Presents a Key Near-Term Milestone
A substantial portion of the Mineral Reserves, notably from the Inesperada and Dumbo pits, is contingent on the approval of an Environmental Impact Declaration (Declaración de Impacto Ambiental, DIA) and associated sectoral permits. These approvals are targeted for late 2026 to early 2027, with full permitting expected by Q4 2027. The company considers there to be a reasonable basis to expect the permits will be granted, but acknowledges the inherent uncertainty and potential impact on the production schedule if delays occur.
The operation holds all necessary permits for existing activities and maintains a comprehensive environmental management system. The site’s extreme aridity and low acid rock drainage potential are favourable environmental factors. Community engagement is focused on the nearby municipality of Taltal, with commitments to local employment and social investment.
Geological Modelling and Resource Classification Underpin Confidence
The updated Mineral Resource Estimate incorporates a robust geological model based on extensive drilling and sampling, with a 25 x 25 metre drill spacing defining Indicated Resources and a denser 3.5 x 20 metre channel grid supporting Measured Resources. The total Measured and Indicated Resources amount to approximately 17 million tonnes grading 0.94 g/t gold and 6.11 g/t silver, containing 511,000 ounces of gold and 3.269 million ounces of silver. Inferred Resources add a further 2 million tonnes at higher grades but are excluded from economic analysis.
The deposit is a classic high-sulfidation epithermal system, structurally controlled with distinct ledge and halo mineralisation domains. The resource classification aligns with industry standards and supports the declared Mineral Reserves.
Mining Methods and Production Schedule Reflect Operational Realities
The mine plan relies entirely on conventional open-pit mining methods with hydraulic excavators and haul trucks, supported by a contracting model. Mining dilution is set at 10% with 90% mining recovery. The plan includes six open-pit phases and reprocessing of three heap leach pads, with a maximum extraction rate of 92 kilotonnes per month per sector. Processing plant capacity constraints limit agitated leach feed to around 1,000–1,200 tonnes per day and heap leach throughput to approximately 174 kilotonnes per month.
Historical underground workings present in some pits are accounted for in the design, with conservative mining rates applied to manage cavity interactions. Waste rock dumps are designed based on existing infrastructure, and the tailings storage facility requires raising to accommodate future tailings volumes.
What to Watch Next
Austral Gold’s ability to secure the pending environmental permits for the Inesperada and Dumbo areas will be critical to unlocking a significant portion of the Mineral Reserves and sustaining the mine plan through to 2040. Additionally, the company’s plans to evaluate underground mining potential could provide upside to the current open-pit focused reserve base. Metallurgical performance during heap reprocessing and fresh ore processing will also be pivotal in meeting production and cost targets.
Bottom Line?
The Guanaco update positions Austral Gold for steady value generation, but permit approvals and metallurgical execution remain key hurdles.
Questions in the middle?
- Will Austral Gold secure the DIA and sectoral permits on schedule to unlock key reserves?
- How might underground mining potential reshape Guanaco’s long-term production profile?
- Can metallurgical recoveries from heap reprocessing meet expectations amid operational challenges?