Stavely Minerals Studies Smaller Mine Options for Thursday’s Gossan Copper Project
Key Takeaways
- Stavely has started studies into three alternatives to the 3-stage, 4Mtpa open pit at Thursday's Gossan: a small-footprint underground, a hybrid starter pit moving underground, and a heap leach of the chalcocite blanket.
- The benchmark to beat is the August 2026 Scoping Study: pre-tax NPV7 of A$818M, 40% IRR, 2.5-year payback and about A$110M average annual free cash flow.
- The company expects the alternatives to have lower NPVs but be less capital intensive, potentially delivering IRRs comparable to 40%, though these are expectations, not results.
- The underground option targets the Cayley Lode at 9.1Mt at 1.6% copper-equivalent, while the heap-leach option covers 22Mt at 0.39% copper in the chalcocite blanket.
- Chair Chris Cairns says the large-scale case would likely require a development partner or a sale, and no NPV, capex figures or study completion date have been disclosed for the alternatives.
Stavely Minerals launches studies into alternative Thursday’s Gossan development options
Stavely Minerals (ASX: SVY) has commenced studies into alternatives to the large-scale 3-stage open pit and 4Mtpa processing case presented in the Thursday’s Gossan Scoping Study (ASX announcement 10 August 2026). The update was released on 13 October 2026.
Three options are on the table. They are a “small-footprint” underground, a “hybrid” starter open pit transitioning to underground operations, and a separate, but not exclusive, option to heap-leach the chalcocite-enriched blanket.
Thursday’s Gossan forms part of the 100%-owned Stavely Copper-Gold Project in western Victoria. The project hosts a Mineral Resource estimate of 59Mt at 0.53% copper-equivalent (0.43% copper, 0.08g/t gold and 2.7g/t silver).
For you as an investor, the message is that the company is widening its options rather than committing to a single path. The announcement does not say any decision has been made.
Chris Cairns, Chair and Managing Director
“Rather than staying blinkered on one development option, Stavely Minerals sees greater value in assessing the full range of development options to optimise the development pathway for Thursday’s Gossan…”
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Scoping Study baseline: the large-scale benchmark
The August 2026 Scoping Study outlined forecast outcomes for a large-scale 3-stage open pit and 4Mtpa processing operation. These figures are the yardstick the alternatives will be compared against:
- Pre-tax NPV7 of A$818M (net present value, the estimated value today of future cash flows, discounted at 7%)
- IRR (internal rate of return, the annualised return on the investment) of 40%
- Projected payback in 2.5 years of production
- Average annual free cash flow from first production of ~A$110M
- Net cashflow from operations of A$1.4B
- Life-of-mine all-in sustaining costs (AISC) of US$3.76/lb copper, and US$2.75/lb copper for the first three years
| Metric | Large-scale open pit | Note |
|---|---|---|
| Process plant and site infrastructure | $333m | Including a 30% contingency |
| Pre-production stripping | $139m | Expected to be the largest |
The company states the large-scale open pit scenario is expected to have delivered the largest NPV, but is also expected to require the largest capital expenditure and pre-production stripping cost. That trade-off is the reason for the new work.
What will the new studies assess?
The mineralisation at Thursday’s Gossan has three distinct styles: the high-grade, steeply dipping Cayley Lodes, low-grade “halo” mineralisation around those lodes, and a flat-lying, weathering-related secondary chalcocite-enriched blanket. The blanket is between 40-50m thick and typically located 30-80m from surface.
According to the company, that variety allows alternative development options to be investigated. The options, with the resource support cited, are:
- A “small-footprint” underground focusing on the high-grade Cayley Lode (9.1Mt at 1.6% copper-equivalent, with 1.2% copper, 0.27g/t gold and 8.4g/t silver)
- A “hybrid” development based on a starter open pit transitioning to underground operations
- A separate, but not exclusive, option to heap-leach the chalcocite-enriched blanket (22Mt at 0.39% copper)
The objective is to provide comparative information on the options, assessing:
- Capital expenditure requirements and efficiency
- Optimal processing rates
- Relative metals production levels and revenue
- Relative costs and processing options (standalone vs. toll treatment / ore sales)
The announcement does not disclose NPV, capital expenditure or production figures for any of the alternatives.
Heap leaching and development scenarios explained
Heap leaching is a processing method where ore is stacked in a pile and treated to extract metal. The announcement does not detail how it would be applied at Thursday’s Gossan, only that it is being studied for the chalcocite-enriched blanket.
In general terms, open pits move large volumes of rock and require significant upfront stripping, which is the removal of waste rock to reach ore. Underground mining targets narrower, higher-grade zones with a smaller surface footprint, and a starter pit followed by underground operations combines the two.
The common thread is a trade-off between scale and capital. Targeting higher-grade material can mean mining less rock, which is why the company links the Cayley Lode focus to the prospect of being less capital intensive.
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What does this mean for the investment case, and what are the next steps?
The company says it is envisaged that the alternatives are likely to have lower NPVs but will also be less capital intensive, potentially resulting in IRRs comparable to the 40% base case. Those are expectations, not results.
The company also says the alternatives may offer a simpler permitting pathway and attract increased community support.
A full investigation is expected to enable a full cost/benefit analysis of the different scenarios, as well as an assessment of the likely timeline and pathway to secure project approvals and funding. The announcement does not give a completion date for the studies.
Cairns said the Scoping Study highlighted a very large-scale project with a projected CAPEX that would likely require Stavely to either secure a development partner or sell to a multi-asset company with a bigger development profile. He added that a new partner or owner may not view the opportunity the same way, and that the company wants shareholders to realise maximum value from the asset “in a rising copper demand environment.”
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