How Revolver Resources’ Dianne Upgrade Sets Stage for 2026 Copper Mine Restart
Revolver Resources has upgraded its Dianne Copper Deposit resource with a 140% increase in Indicated material and a 26% rise in copper grade, setting the stage for a targeted mining restart in 2026.
- Updated Mineral Resource Estimate totals 1.31 Mt at 1.38% copper
- 140% increase in Indicated resource classification
- 26% improvement in overall copper grade
- Heap leach processing and SX-EW planned for capital-lite restart
- Final Investment Decision targeted for late 2025 or early 2026
Resource Upgrade and Project Context
Emerging copper producer Revolver Resources Holdings Ltd (ASX, RRR) has announced a significant upgrade to the Mineral Resource Estimate (MRE) for its Dianne Copper Deposit in north Queensland. The updated estimate now stands at 1.31 million tonnes grading 1.38% copper, alongside zinc and silver credits, representing a material improvement over previous assessments.
This upgrade is driven by a recent pre-development drilling program that has increased the Indicated resource by 140%, now comprising 1.09 million tonnes, and boosted the average copper grade by 26%. The contained copper metal has edged slightly higher to 18,050 tonnes, underpinning the project's economic potential.
Geological and Metallurgical Advances
The Dianne Deposit is a volcanogenic massive sulphide system with a complex mineralogy including chalcopyrite, chalcocite, sphalerite, and silver. The updated geological model incorporates 102 validated drill holes, combining historical and modern data, and extends from surface to 210 meters depth. Notably, the Greenhill supergene oxide zone near surface is amenable to low-cost heap leach processing, a key factor in the planned capital-lite mine restart.
Metallurgical testwork has demonstrated excellent copper recoveries exceeding 90% for oxide mineralization and flotation recoveries above 90% for sulphide ores. These results support the feasibility of heap leach plus solvent extraction-electrowinning (SX-EW) processing to produce copper cathode, aligning with the company’s strategy for near-term production.
Development Outlook and Strategic Implications
Revolver’s Managing Director, Pat Williams, emphasized the importance of the resource upgrade in providing confidence for the mine restart. The company is advancing pre-construction earthworks and other development workstreams, targeting a Final Investment Decision (FID) by late 2025 or early 2026. If successful, first copper cathode production is expected in the second half of 2026.
Beyond the immediate open pit, the high-grade primary mineralization remains open at depth, offering potential for future underground mining and extended mine life. This flexibility could enhance the project’s long-term value and appeal to investors seeking exposure to copper amid global electrification trends.
Environmental and Regulatory Considerations
The company has lodged a full Environmental Authority application with Queensland regulators and completed detailed waste characterization and acid accounting. Environmental management plans are designed to meet stringent EPA standards, reflecting a responsible approach to sustainable mining practices.
Overall, the Dianne Project’s upgraded resource, combined with positive metallurgical and environmental assessments, positions Revolver Resources well to capitalize on rising copper demand and deliver shareholder value through a timely mine restart.
Bottom Line?
With a strengthened resource base and clear development pathway, Revolver Resources is poised to re-enter copper production, but execution risks remain ahead of the critical Final Investment Decision.
Questions in the middle?
- Will Revolver secure the necessary financing and offtake agreements to support the FID?
- How will metallurgical optimization efforts impact processing costs and recoveries?
- What is the potential scale and timeline for expanding the resource at depth or along strike?
