Catalyst uncovers a much larger Keillor gold system as production ramps up
Catalyst Metals has lifted the Keillor gold Resource from 81koz to 307koz after a major drilling campaign, while the operating mine ramps up near the Plutonic processing plant. The company expects an Ore Reserve update to extend Keillor’s initial three-year mine life.
- Keillor Resource rises 280% to 307koz at 3.0g/t Au
- Underground Indicated Resource increases 503% to 187koz
- Mine declared commercial production in April 2026
- Reserve update expected to extend the initial three-year mine life
- Catalyst continues targeting approximately 2Moz of Plutonic Belt Reserves
Keillor Resource jumps to 307koz
Catalyst Metals Limited (ASX:CYL) has turned a lightly drilled, long-dormant deposit into a substantially larger operating asset, increasing Keillor’s Mineral Resource by about 280% to 3.2 million tonnes at 3.0 grams per tonne gold for 307,000 ounces.
The result compares with the previous 81koz Resource, which was based largely on drilling completed before 2000. The updated estimate comprises 285koz underground and 21koz in an open-pit component. It includes 207koz of Indicated material and 99koz Inferred, with no Measured Resource reported.
Underground drilling supports mine-life extension
The most consequential change sits in the underground category. Keillor’s Indicated underground Resource has risen about 503% to 187koz, giving the portion currently being mined a much larger drilling-supported inventory than the earlier estimate.
Catalyst used 30,181 metres of underground diamond drilling, alongside 52,790 metres of surface drilling, 578 metres of sludge drilling and 1,786 metres of face sampling. The company says the work was aimed not only at growing the Resource, but also at de-risking the immediate mine plan.
Deeper drilling has also produced indications of possible further growth, including a 7-metre intercept at 5.1g/t gold 350 metres beneath the existing West Lode and a 4-metre intercept at 10g/t 180 metres beneath the East Lode. Those results are described as potential extensions rather than additional Resources in the current estimate.
Keillor is already producing ore
Unlike a typical exploration-stage Resource upgrade, Keillor is already in production. Catalyst declared the underground mine commercial in April 2026, transported first stoping ore to the Plutonic processing plant during the June quarter and says ramp-up is progressing in line with plans.
Mining is currently focused on the Main and West lodes, with multiple mining fronts established and grade-control drilling completed for the first 15 months of production. A short-term contractual paste plant operation has been introduced to support extraction of the high-grade resource, while development capital is now largely spent. Catalyst expects ongoing capital requirements to be limited to mine development.
Metallurgical testing indicates the ore is free milling, with recovery above 92% and gravity recovery above 40% in the latest test work. The deposit is located 40 kilometres from the Plutonic plant, with ore haulage reported at A$13.75 per tonne.
Reserve conversion remains the next test
The Resource growth is not yet an equivalent increase in mineable inventory. Catalyst is preparing an updated Ore Reserve and expects it to support a mine-life plan beyond Keillor’s initial three years. That conversion has not been reported, and the current Resource still contains Inferred material that carries lower geological confidence than Indicated material.
Keillor is the third of six mines in Catalyst’s plan to lift long-term Plutonic Belt production to approximately 200koz a year and build Reserves of about 2Moz. The company says drilling is continuing at Keillor, Cinnamon, Trident and Old Highway, but has warned that its September 2025 10-year guidance is only a general guide because permitting, Resources and Reserves, geological interpretation, operating delays and processing capacity have changed.
Bottom Line?
The Resource upgrade materially strengthens Keillor’s growth case, but the upcoming Reserve statement and ramp-up performance will determine how much of the geological uplift becomes production and mine life.
Questions in the middle?
- How much of the 307koz Resource will convert into the pending Keillor Ore Reserve?
- Can the mine sustain the expected steady-state production rate of about 20koz a year during ramp-up?
- Will further drilling at Keillor and the other Plutonic Belt deposits support the approximately 2Moz Reserve and 200koz annual production targets?
