Viridis doubles REE tonnage in Brazil

Viridis Mining and Minerals (ASX: VMM) has unveiled an initial reserve estimate of more than 200 million tonnes at its Colossus ionic adsorbed clay project in Brazil, underpinning a potential high-grade rare earth mine with top economics. 

The total tonnage — derived solely from measured and indicated resources — more than doubles the reserve estimate of 98.5 million tonnes and the 20-year mine life that underpinning its prefeasibility study issued last month, the Australian miner said Wednesday. It posted grades of 2,640 parts per million (ppm) in total rare earth oxides (TREOs) and 740 ppm in magnetic rare earth oxide (MREOs) versus 936 ppm MREOs in July. 

“Our robust reserve base now underpins a potential mine life of up to 40 years, doubling the scale of our recent PFS, and provides the platform to establish Viridis as a long-term, tier-one supplier of the magnet rare earths critical to global decarbonization and electrification,” managing director Rafael Moreno stated.

Shares in Viridis Mining fell 9.3% on Wednesday to close at A$1.27 apiece in Sydney, valuing the company at A$125 million (C$112 million). They’re traded in a 52-week range of A18¢ to A$1.44.

‘Economically robust’

The mine pits supporting the reserve align with the ultra-high-grade feed that formed the backbone of
the PFS, validating the Colossus project as “the most economically robust rare earth project globally,” Viridis said.

Colossus could deliver 9,400 tonnes of TREO production annually at all-in sustaining costs of $9.30 per kg, according to the PFS. The pre-tax net present value discounted at 8% was estimated at $1.41 billion with an internal rate of return of 43%.

The total contained TREO reserve of 529,000 tonnes would support a long-duration production of mixed rare earth carbonates. Viridis said it will prioritize magnet rare earth oxides (neodymium, praseodymium, dysprosium and terbium) to maximize basket value.

Situated in the state of Minas Gerais, the Colossus project comprises 228.6 sq. km of licenses within and around the Poços De Caldas alkaline complex, home to some of the highest-grade ionic adsorbed clay intercepts recorded globally. Viridis acquired the rights to the project in 2023 and has since conducted multiple rounds of drilling, with rare earths intercepted within all concessions to date.

Growth potential

The 200.6-million-tonne reserve estimate represents just 12% of the broader Colossus landholding, the company said. It only included converted resources from the Northern Concession, Southern Complex and Capão da Onça deposits. High-grade zones such as the Tamoyo prospect (with the highest MREO content to date at 770 ppm) remain outside this initial reserve, Viridis said.

This, says Moreno, underscores Colossus’ “immense growth potential and strategic significance” as a globally critical source of magnet rare earths.

Viridis may become the first producer of refined rare earths in Brazil through its joint venture with Ionic Rare Earths (ASX: IXR), Viridion. It has exclusive global (excluding Asia and Uganda) rights for the refining of individual rare earth oxides and rights to Ionic’s recycling technology.

Brazilian investment firms ORE and Régia Capital provided $30 million in funding for Colossus as Viridis approaches a construction decision. Other backers include the Brazilian National Bank for Economic and Social Development and the Federal Agency for Funding Authority for Studies and Projects in Brazil. They launched a joint public call earlier in the year to invest as much as 5 billion reais (US$903 million) across the country’s leading strategic mineral projects.