Meteoric Resources (ASX:MEI) has updated the global mineral resource estimate (MRE) for its Caldeira Rare Earth Element Ionic Clay Project in Brazil.
The update reflects a 246% increase in measured resources to 128 million tonnes (Mt) @ 2,815 parts per million (ppm) total rare earth oxides (TREO).
Caldeira’s global MRE now stands at 1.6 billion tonnes @ 2,317 ppm TREO, with a 1,000 ppm TREO cut-off grade.
The TREO basket contains critical magnetic rare earth oxides (MREO), including 209,000 tonnes of praseodymium oxide, 594,000 tonnes of neodymium oxide, 6,000 tonnes of terbium oxide, and 34,000 tonnes of dysprosium oxide.
Meteoric says detailed 50m by 50m infill drilling across the southern licences — Capão do Mel, Figueira, and Soberbo — and detailed 3D geological modelling enabled the conversion of indicated resources to measured resources.
Across the three deposits, measured resources increased from 11Mt to 102Mt, increasing confidence in the upcoming Definitive Feasibility Study (DFS) for Caldeira.
Managing Director Stuart Gale says upgrading the measured resources is an important step to increase geological and metallurgical confidence as the company finalises the DFS.
“This reduces future risk and uncertainty, which supports upcoming investment and financing decisions,” Gale says.
“From a future operational standpoint, our improved understanding of the resource characteristics supports efficiencies in mine planning and operational reliability.
“This in turn delivers more precise mine scheduling, better recovery, and grade control, to lower operational risks during production.”
Meanwhile, infill aircore drilling is ongoing at the Barra do Pacu prospect to convert further indicated resources to measured status. The company says results will ultimately be incorporated into future resource estimations.
The Caldeira Project features ionic adsorption clay-hosted rare earth mineralisation, which allows for low-cost, simple metallurgical processing.
Testwork completed so far demonstrates global average recoveries of 55% TREO and 71% MREO using an ammonium sulfate leach process.
The company says environmental permitting is progressing, with the preliminary licence granted by the State Environmental Protection Agency (FEAM) in December 2025; and the installation licence expected in the December quarter of 2026.
Meteoric Resources is a mineral explorer and developer focused on its flagship Caldeira Rare Earths Project in the Minas Gerais state of Brazil.
Write to Paula Fabe at Mining.com.au
Images: Meteoric Resources
