Viridis Unveils 200.6Mt Maiden Reserve, Doubling Colossus Mine Life to 40 Years

A Landmark Milestone for Colossus

Viridis Mining and Minerals Limited has taken a significant step forward in the development of its Colossus Rare Earth Project in Brazil by announcing a maiden JORC Probable Ore Reserve of 200.6 million tonnes. This reserve boasts an impressive total rare earth oxide (TREO) grade of 2,640 parts per million (ppm) and a magnetic rare earth oxide (MREO) grade of 740 ppm, positioning Colossus as a globally competitive ionic adsorption clay rare earth project.

The declaration of this reserve effectively doubles the mine life from the previously announced 20 years to an estimated 40 years, underpinning a long-term production profile with an average annual ore feed of 5 million tonnes. The reserve's low strip ratio of 0.45, 1 further enhances the project's economic attractiveness by minimizing waste removal relative to ore mined.

Resource Conversion and Project Scale

The reserve conversion draws exclusively from the Measured and Indicated Mineral Resources, deliberately excluding Inferred material to maintain a high confidence level. This conversion represents 61% of the current resource base within the Northern Concessions, Southern Complex, and Capão da Onça deposits. Notably, this reserve accounts for only 12% of Viridis' total landholding, leaving substantial upside potential in high-grade zones such as the Tamoyo Prospect, which remains outside the current reserve boundary.

Viridis’ Managing Director, Rafael Moreno, highlighted the strategic importance of this milestone, emphasizing the reserve's scale and quality as a foundation for establishing Viridis as a tier-one supplier of magnet rare earths critical to the global energy transition.

Sustainable Mining and Processing

The Colossus Project is designed with sustainability at its core. Mining will be conducted via shallow, free-dig open pits without drilling or blasting, reducing environmental disturbance and operational complexity. A key feature is the progressive in-pit backfilling of waste and filtered process residues, eliminating the need for conventional tailings storage facilities and enabling concurrent land rehabilitation.

The processing flowsheet, anchored by extensive testwork from the Australian Nuclear Science and Technology Organisation (ANSTO), employs low molar concentration ammonium sulfate leaching at ambient conditions. This approach maximizes metallurgical recoveries while minimizing reagent use and water consumption. The project plans to recycle approximately 75% of process water and source power from a renewables-heavy grid, further reducing its environmental footprint.

Robust Economics and Next Steps

The maiden reserve declaration aligns with the assumptions and economic outcomes of the recently completed Pre-Feasibility Study (PFS), which reported a post-tax net present value (NPV8) of US$899 million and an internal rate of return (IRR) of 34%. Operating costs remain competitive, with a C1 cash cost of approximately US$6.20 per kilogram of TREO.

Viridis is now focused on advancing environmental permitting, detailed feasibility studies, metallurgical optimisation, and offtake negotiations. The company benefits from strategic partnerships with Brazilian financial institutions and investment firms, positioning it well to secure project financing and move towards a final investment decision.

Strategic Importance in the Rare Earth Supply Chain

Colossus’ location within the Poços de Caldas Alkaline Complex, a well-established mining hub with existing infrastructure and skilled workforce, adds to its execution readiness. The project’s low-impact mining and processing methods, combined with its high-grade magnet rare earth content, make it a critical potential supplier for the global decarbonisation and electrification markets, particularly for electric vehicles and renewable energy technologies.