Celsius Resources Ltd (ASX:CLA, AIM:CLA) has unveiled the maiden JORC-compliant Ore Reserve Estimate for its Maalinao-Caigutan-Biyog (MCB) Copper-Gold Project in the Philippines - a significant technical and commercial milestone for the emerging producer.
The reserve underpins an updated Feasibility Study and ongoing financing discussions and confirms strong metallurgical, geological and operational fundamentals for a long-life underground mine.
130 million tonnes in maiden reserve supports long-life development
The maiden Ore Reserve for MCB totals 130.2 million tonnes at 0.66% copper and 0.21 g/t gold, containing 856,000 tonnes of copper and 891,000 ounces of gold, using a 0.46% copper-equivalent cut-off.
The estimate comprises 22.1 Mt of Proven Reserves and 108.2 Mt of Probable Reserves, aligned with Measured and Indicated portions of the resource base.
The reserve forms the basis of the updated Feasibility Study and validates the proposed underground mine plan, which integrates sub-level open stoping (SLOS) with paste backfill, dry-stack tailings and a conventional flotation plant. DMT Consulting, acting as the independent Competent Person, verified the Ore Reserve in accordance with JORC 2012.
Technical director Peter Hume said the outcome reinforced confidence in the deposit’s long-term potential, highlighting strong community engagement and the role of local engineering teams in advancing the project.
“The Maiden JORC Ore Reserve Estimate for the MCB Copper-Gold Project is a major milestone that confirms the strength and long-term potential of the deposit, reinforcing our confidence in the Project’s capacity to deliver sustained value for shareholders and stakeholders.
"We extend our sincere appreciation to the Balatoc community whose partnership and support—especially during the recent drilling and field activities—were vital in completing the technical work that underpins this Reserve Estimate. Their cooperation continues to guide our commitment to responsible project development.
"We also acknowledge the dedication of MMCI staff and our young professional engineers, whose hard work and technical discipline have been instrumental in achieving this outcome. Their contribution reflects the growing capability of the next generation of Filipino mining professionals.
"This Ore Reserve Estimate is a testament to the collective effort and professionalism of everyone involved. We look forward to advancing the MCB Project in a way that brings enduring benefits to our shareholders, our host communities, and the country.”
Robust geological model supported by extensive drilling
The reserve draws on a comprehensive geological interpretation supported by more than 31,600 metres of diamond drilling completed between 2006 and 2025. The mineralisation is consistent with a classic porphyry copper-gold system, controlled by intrusive tonalite bodies and a series of steeply dipping structures trending roughly 050 degrees.
High-grade domains (Type 1HGV and Type 1HGH) sit within and around the intrusive contact zones, while a broad halo of lower-grade copper mineralisation (Type 3LG) extends across widths of up to 400m at depth. The updated Mineral Resource Estimate referenced in the reserve work totals 343 Mt at 0.46% Cu and 0.12 g/t Au, underpinning confidence in continuity across production areas.
Variogram and statistical analysis demonstrated strong grade continuity within key domains, allowing the application of Ordinary Kriging as the primary interpolation method. No top cuts were required due to the absence of outlier-driven distortions.
Feasibility study confirms mine plan, metallurgy and cost parameters
The updated Feasibility Study and FEED program, now nearing completion, confirm the technical viability of the proposed underground operation. Mining will proceed on a primary-secondary stope sequence with 20 m × 20 m × 30 m stopes, 10% dilution and 95% mining recovery. Production is designed to ramp to 2.6 Mt per annum from year three.
Metallurgical test work demonstrates 95% copper recovery and 77% gold recovery, producing a clean copper-gold concentrate with no penalty elements. A single-stage SAG circuit with rougher and cleaner flotation will support concentrate production of ~22,800 tonnes of copper metal annually over the first decade of operations.
Cost assumptions are consistent with industry benchmarks: mining at US$18.79/t, processing at US$14.89/t, general administration at US$2.88/t, and long-term metal prices of US$4.50/lb copper and US$3,200/oz gold. Economic modelling shows strong resilience under multiple commodity price scenarios.
Environmental approvals, social licence and infrastructure progressing
The project is fully permitted under Philippine mining regulations, with a granted Mineral Production Sharing Agreement (MPSA-356-2024-CAR), a completed Environmental Impact Statement, and an issued Environmental Compliance Certificate. Importantly, Celsius’ Philippine affiliate Makilala Mining Co. Inc. has secured Free, Prior and Informed Consent (FPIC) from the Balatoc Indigenous community, together with local government endorsements.
Environmental design incorporates low-impact features, including dry-stack tailings and underground backfilling. No mining will occur beneath nearby communities, and methods that could induce surface subsidence were rejected to protect the Pasil River.
Non-process infrastructure includes a new site access road, HV transmission line connection to the Luzon Grid, accommodation facilities for up to 272 personnel, water supply from Karatangus Creek and concentrate export via Salomague Port.
Outlook: financing discussions and study completion underway
With the reserve now established, Celsius will continue advancing financing discussions with international partners and institutions. Completion of the JORC-compliant Feasibility Study and FEED program is expected by the end of 2025, enabling the transition to development.
The company says the MCB Project is positioned to deliver long-term benefits to shareholders, host communities and the Philippine economy through responsible, modern underground mining.