Alkane Resources has lifted group Ore Reserves to 1.374 million ounces after exploration and resource conversion replaced depletion across its operating portfolio. The FY26 update also puts Björkdal’s open-pit restart and Costerfield’s extended mine life into sharper focus.
- 1.374Moz of group Proven and Probable gold reserves
- Resource replacement at Björkdal, Tomingley and Costerfield
- Björkdal reserves rise 3.7% to 563koz
- Costerfield mine life extends to October 2032
- Storheden enters Indicated Resource category
Exploration Replaces Group Depletion
Alkane Resources (ASX:ALK) has reported 1.374 million ounces of group Proven and Probable gold Ore Reserves as at 30 June 2026, a portfolio headline that matters more than any single deposit table. The company says its producing assets replaced mined depletion through exploration, grade control and resource conversion, while group Measured and Indicated Resources rose to 8.641Moz of gold across 578.8 million tonnes.
The reserve base spans 25.488 million tonnes at 1.7 g/t gold, alongside 15,000 tonnes of contained antimony at Costerfield. The numbers include 641koz at Tomingley, 563koz at Björkdal and 170koz at Costerfield. Boda-Kaiser, the large copper-gold project, remains unchanged in the resource inventory and contributes no Ore Reserves to the group total.
Björkdal Adds Reserves While Restarting Open-Pit Mining
Björkdal’s Ore Reserves increased 3.7% to 563koz, despite 48koz of production depletion. The updated estimate includes 13.12Mt at 1.33 g/t gold and supports an approximately 10-year mine plan at around 1.4Mtpa, with average production of about 51koz a year over the next nine years.
The operational twist is that the Swedish mine is moving beyond its recent underground-and-stockpile model. Stripping is under way at the Nylunds North Pit, with first ore expected in October 2026, while preparations to mine the Main Pit Crown Pillar are planned for 2027. The plan also includes 161,000 tonnes from Norrberget in FY2036, although Norrberget still requires an environmental permit before mining can begin.
Exploration has enlarged the broader resource picture. Björkdal and nearby deposits contain 1.497Moz of Measured and Indicated Resources, while Storheden now contributes 87koz in the Indicated category and 125koz Inferred. Storheden has no Ore Reserves yet, and its eventual value depends on further drilling, mine planning and permitting. The deposit’s inclusion follows the latest drilling that extended the known vein system beside the existing operation.
Tomingley and Costerfield Extend the Operating Base
At Tomingley, Ore Reserves rose 3.2% to 641koz after 95koz of depletion, including record site production of 80koz. Roswell was the main growth engine: additional drilling expanded the underground resource, while the operation’s reserve schedule now includes 11.401Mt at 1.7 g/t gold. San Antonio contributes 214koz of open-pit reserves, but its grade-control drilling remains incomplete and the estimate has not been updated since 2022.
Costerfield delivered the most pronounced percentage uplift, with gold reserves rising 13.3% to 170koz and antimony reserves reaching 15.0kt. The Victorian gold-antimony operation’s demonstrated mine life has increased from five years to six, with production scheduled to October 2032. Growth came from Brunswick South, Kendal, Cuffley and other resource conversion, though the reserve estimate also carries the operational complexity of narrow-vein mining and high dilution in some remnant areas.
The Numbers Still Depend on Execution
Alkane’s reserve replacement is plainly favourable, but it is not the same as adding a fully de-risked new mine. Storheden remains outside the reserve base, Norrberget still needs approvals, San Antonio’s grade-control work is unfinished, and Tomingley’s technical report flags a gap between laboratory recovery expectations and recent plant performance after its refractory-gold upgrade. At Costerfield, future reserve confidence will depend partly on converting drilling success into mineable tonnes without losing too much to dilution.
The next test is therefore operational rather than geological: whether the new tonnes can be mined, processed and permitted on the timetable embedded in the reserve statements. For Björkdal, that begins with Nylunds ore in October; for Costerfield, with Brunswick South and Kendal development; and for Tomingley, with Roswell’s ongoing grade-control campaign.
Bottom Line?
The reserve replacement is encouraging, but the next value test is conversion: turning exploration ounces into permitted, recoverable production without dilution or processing performance eroding the plan.
Questions in the middle?
- Can Storheden be converted from a large Resource into Ore Reserves before Björkdal’s underground inventory declines?
- Will Björkdal’s Nylunds and Crown Pillar restart deliver the planned open-pit tonnes on schedule?
- Can Roswell, Brunswick South and Kendal replace future depletion as reliably as they did in FY26?