Core Lithium Doubles Grants Ore Reserve, Boosts Finniss Total to 10.73Mt
Core Lithium has doubled the Grants Ore Reserve by shifting to underground mining, lifting total Finniss Ore Reserves to 10.73 million tonnes at 1.29% lithium oxide. This update supports a robust 10-year mine plan with potential for extended operations.
- Grants Ore Reserve doubled to 1.15Mt via underground mining
- Total Finniss Ore Reserves increased to 10.73Mt at 1.29% Li2O
- Mineral Resource Estimate slightly up to 48.5Mt including tailings material
- New Exploration Target of 10.9–16.5Mt at 1.5–1.7% Li2O defined
- Capital costs estimated at $175–200 million with spodumene price at US$1,330/t
Overview of the Updated Ore Reserve
Core Lithium Ltd (ASX: CXO) has announced a significant update to its Finniss Lithium Project’s Ore Reserve and Mineral Resource Estimate as of 30 April 2025. The standout development is the doubling of the Grants Ore Reserve to 1.15 million tonnes, achieved by transitioning from open-pit to underground mining. This strategic shift not only unlocks more material but also aims to reduce operational costs.
When combined with the updated BP33 Ore Reserve, the total Ore Reserves at Finniss now stand at 10.73 million tonnes grading 1.29% lithium oxide (Li2O). This reserve underpins the first 10 years of the company’s Restart Study mine plan, signaling a solid foundation for sustained production.
Mineral Resource and Exploration Targets
The overall Mineral Resource Estimate has seen a modest increase of 0.6% to 48.5 million tonnes at 1.26% Li2O. Notably, this includes an additional 310,000 tonnes at 0.66% Li2O from mineralised material within the Tailings Storage Facility (TSF) and coarse reject stockpiles, now classified as an Indicated Mineral Resource. This reflects Core Lithium’s efforts to maximise resource utilisation by incorporating previously overlooked material.
Beyond the defined resources, Core Lithium has outlined an Exploration Target ranging from 10.9 to 16.5 million tonnes at grades between 1.5% and 1.7% Li2O. This target spans two deposits: BP33 and the Blackbeard prospect, located approximately 20km from BP33. Early drilling at Blackbeard has revealed encouraging high-grade intersections, suggesting a substantial mineralised system that warrants further exploration.
Operational and Financial Considerations
The updated Ore Reserve incorporates detailed study work including mining method optimisation, processing flowsheet improvements, and infrastructure planning. The Grants deposit will be mined using long hole open stoping with pillars, while BP33 will employ long hole open stoping with paste backfill, reflecting tailored approaches to each deposit’s geology and geometry.
Core Lithium estimates initial capital expenditure between $175 million and $200 million to support the restart of operations, including processing plant upgrades to increase capacity to 1.2 million tonnes per annum. Operating costs are projected at $63–72 per tonne for underground mining, with spodumene pricing assumptions set at US$1,330 per tonne, based on consensus forecasts.
Regulatory and Environmental Status
All key approvals and licences necessary for the restart of operations are in place or progressing through regulatory channels. Minor variations to the Mining Management Plan are being assessed to reflect the revised underground mining methods and infrastructure changes. Environmental considerations, including waste rock and tailings management, have been addressed with approved plans, supporting the project’s social license to operate.
Looking Ahead
Core Lithium’s updated Ore Reserve and Mineral Resource position, combined with defined exploration targets, set the stage for a potentially extended mine life beyond the initial 10-year plan. The company is preparing to undertake drilling programs to test the Blackbeard and BP33 exploration targets, aiming to convert these into Mineral Resources and eventually Ore Reserves. Market conditions, spodumene prices, and regulatory progress will be critical factors shaping the project’s trajectory.
Bottom Line?
Core Lithium’s strategic shift to underground mining and resource expansion at Finniss signals a promising decade ahead, but exploration and regulatory milestones remain key to unlocking full potential.
Questions in the middle?
- Will drilling at Blackbeard and BP33 convert exploration targets into new Mineral Resources?
- How will spodumene market price fluctuations impact the economic viability of the expanded Ore Reserves?
- What is the timeline and certainty around regulatory approvals for the revised underground mining plan?
