Catalyst converts Cinnamon discovery into 232koz underground Reserve

Cinnamon reaches Reserve status within a year

Catalyst Metals Limited (ASX:CYL) has moved Cinnamon from underground discovery to a maiden Ore Reserve in less than 12 months, giving the Plutonic Gold Belt a sixth planned ore source. The broader Cinnamon Resource now stands at 6.9 million tonnes grading 2.5 grams per tonne for 541,000 ounces, a 370% increase from the previously reported 145koz.

The underground component accounts for 4Mt at 3.4g/t for 434koz, including a Probable Reserve of 2.4Mt at 3.0g/t for 232koz. The open-pit portion contributes a further 2.9Mt at 1.2g/t for 108koz, with 88koz classified as Probable Ore Reserves.

Seven-and-a-half-year mine plan built around Plutonic infrastructure

The underground Reserve underpins a 7.5-year production target with steady-state output of about 48koz a year, within the company’s stated 40koz to 50koz range. Catalyst estimates 315koz of gold will be mined and 284koz produced at a 90% recovery rate, with life-of-mine all-in sustaining costs of A$2,357 per ounce.

The plan assumes A$35 million of pre-production capital and ore transport along an existing haul road to the 2Mtpa Plutonic processing plant, 25km away. On the company’s assumptions, the underground operation produces a pre-tax NPV7 of A$408 million and a pre-tax IRR of 78% at a gold price of A$4,500/oz. At A$6,000/oz, the corresponding NPV7 rises to A$726 million and the IRR to 126%. These are pre-tax, pre-feasibility-level estimates rather than a construction decision.

Production target carries an Inferred Resource caveat

The headline economics come with an important qualification: approximately 26% of the Cinnamon life-of-mine Production Target is based on Inferred Mineral Resources. Catalyst says the Inferred material is not the determining factor in project viability and represents only 1% of the material in the forecast payback period, but the company also cautions that Inferred Resources carry a low level of geological confidence and may not convert to Indicated Resources or be realised in production.

The mine design is based on wide, continuous mineralisation, average Reserve stope widths of 25m and favourable ground conditions. Catalyst proposes longhole stoping with paste fill, while also evaluating an alternative standalone box-cut access. The operating plan assumes existing Plutonic facilities, employee capacity and operating systems can absorb much of the required infrastructure.

Repeat conglomerate zones provide the next drilling test

Cinnamon’s high-grade shoot sits within one of several stacked conglomerate units. Drilling has returned mineralisation in four areas outside the current Resource, including intercepts of 8m at 4.7g/t, 8m at 1.6g/t and 0.5m at 21g/t. Those results are not included in the Resource or Reserve, leaving follow-up drilling to determine whether the geological model can be repeated at depth or above the existing orebody.

A second high-grade shoot would materially alter the current development plan, according to Catalyst. For now, the more immediate tests are permitting, conversion of the Inferred component and whether the assumed low-cost access to Plutonic infrastructure survives detailed development work. Catalyst has also warned that its September 2025 10-year Plutonic production guidance remains a general guide after changes to permitting timelines, operational delays and processing capability.