Key Highlights

  • Updated Scoping Study at Western Queen shows an NPV of $86 million (at 8% discount rate) and IRR of 45% at a gold price of A$5,714 per ounce, with all-in sustaining costs of A$4,390 per ounce.
  • Production target of 1.2Mt at 3.2 g/t Au for 125,000 ounces of contained gold over an initial production period of approximately four years, more than doubling production versus the November 2025 study.
  • Updated Mineral Resource Estimate of 3.92Mt at 3.1 g/t Au for 393,100 total ounces, including a high-confidence Indicated Resource of 1.87Mt at 3.7 g/t Au for 223,800 ounces, with the Western Queen Central high-grade zone at 129kt at 11.6 g/t Au for 48,000 ounces.
  • Low upfront Capital requirement of approximately $8 million, underpinned by a five-year toll milling and blending agreement with Gylden Resources at the Kirkalocka processing plant, approximately 185km southeast of Western Queen.

An Improved Case for Western Queen

Rumble Resources Limited (ASX:RTR) has released an updated Scoping Study on its Western Queen Gold Project in Western Australia that presents a materially improved economic picture compared to the November 2025 study that covered only the Western Queen South deposit. The updated study incorporates the Western Queen Central deposit — which hosts a high-grade Indicated Resource of 129,000 tonnes at 11.6 g/t Au for 48,000 ounces situated directly below the historical underground workings — and delivers both a longer mine life and more than double the gold production contemplated in the earlier analysis.

At an assumed gold price of A$5,714 per ounce, the study returns a post-tax net present value of $86 million at an 8% discount rate and an internal rate of return of 45%. These metrics reflect a project with a low upfront capital requirement — approximately $8 million — made possible by the company's five-year toll milling and blending agreement with Gylden Resources, which provides access to the Kirkalocka processing plant approximately 185 kilometres southeast of the mine site without requiring PFS-level processing infrastructure investment.

The Resource and Mine Plan

The study is underpinned by a revised Mineral Resource Estimate of 3.92 million tonnes at 3.1 g/t Au for 393,100 total ounces, announced concurrently with the scoping study. Of this, 1.87 million tonnes at 3.7 g/t Au for 223,800 ounces sits in the higher-confidence Indicated category — a meaningful 57% proportion that increases the geological confidence underpinning the economic assessment.

The Western Queen Central deposit's high-grade core at 11.6 g/t Au changes the character of the mine plan materially. High-grade underground development of this kind allows for selective Mining that can support above-average Revenue per tonne of ore treated — an important Factor in managing the Economics of toll-processed operations where transport and treatment costs are fixed per tonne.

The production target for the initial development period is 1.2 million tonnes at 3.2 g/t Au for 125,000 contained ounces over approximately four years, at a production rate of approximately 30,000 tonnes per month at full capacity. All-in sustaining costs are estimated at A$4,390 per ounce — a figure that sits below the assumed gold price and provides a Margin at current and modelled gold price assumptions.

Only approximately 30% of the current Mineral Resource at Western Queen is included in the initial production target, meaning there is material that could support an extended mine life beyond the initial four-year horizon.

The Tungsten Dimension

One of the more distinctive features of the Western Queen project is the presence of tungsten mineralisation co-mingled with the gold. The company has indicated that metallurgical test work and preliminary Marketing discussions suggest a saleable scheelite concentrate can be produced from Western Queen ore. Tungsten is another critical mineral, with Supply dominated by China and Demand driven by cutting tools, armaments, and high-performance alloys.

The current scoping study has been prepared on a gold-only basis, and the company's next development workstream is a Feasibility Study that will incorporate the tungsten economics into the mine plan. Including a tungsten revenue stream could meaningfully improve project economics, though it also adds complexity to the metallurgical and marketing assumptions. Managing Director Peter Harold described the tungsten co-product as a potentially valuable additional revenue stream that the current toll milling arrangement at Kirkalocka would not capture without installation of a dedicated tungsten circuit.

Sector Context

Western Queen sits approximately 90 kilometres northwest of Mount Magnet in WA's Mid West gold province — an established mining address with existing infrastructure, processing facilities, and workforce access. Underground gold projects in this region have historically attracted toll milling agreements from nearby plant operators looking to utilise surplus processing capacity, and the Kirkalocka arrangement follows this pattern.

The toll processing model reduces upfront capital requirements dramatically — the $8 million estimate for Western Queen compares favourably with full-development capex that can reach $50–200 million for standalone underground operations of comparable scale. However, it also introduces a toll rate cost structure and logistical complexity that owner-operated processing avoids.

Risks

The study is preliminary in nature with an accuracy level of plus or minus 30%, and is based in part on Inferred Mineral Resources (approximately 20% of the production target by mass), which carry lower geological confidence. The study explicitly cautions that further evaluation work is required before Ore Reserves can be estimated. Gold recovery assumptions, tungsten inclusion in the mine plan, finance availability, and regulatory approvals are all material assumptions that may not be realised.

The toll milling arrangement at Kirkalocka introduces dependence on a third-party processing agreement over a five-year term, and any disruption to that Facility could affect production continuity.

What to Watch Next

The commencement of a Feasibility Study incorporating tungsten is the key next development step. Metallurgical test work confirming gold and tungsten recoveries, sourcing project finance, obtaining all regulatory approvals, and the Board making a Final Investment Decision represent the milestones between current study work and first production. Regulatory approval for dewatering of the Western Queen South open pit — flagged as a granted permit during the current period — is also a logistical prerequisite for underground access.