MTM Critical Metals has signed a non-binding memorandum of understanding (MoU) with Meteoric Resources NL to improve the processing of mixed rare earth carbonate (MREC) from the latter’s Caldeira rare earth project in Brazil.

This partnership aims to utilise the flash joule heating (FJH) technology developed by MTM's US subsidiary, Flash Metals USA.

The FJH technology has shown positive results in concentrating valuable magnet and key heavy rare earth elements (REEs) such as neodymium, praseodymium, dysprosium and terbium.

It has demonstrated the ability to separate more than 80% of low-value material in a single flash and recover 81% of terbium without the need for acids or solvents.

The FJH process has the potential to simplify typically complex and expensive rare earth processing. The technology is expected to offer “a potential breakthrough alternative” to the processing, which is currently dominated by Chinese-controlled infrastructure.

MTM managing director and CEO Michael Walshe said: "Our proof-of-concept work on Meteoric's MREC clearly shows the transformative potential of Flash Joule Heating.

"In a single flash we shifted the product mix decisively toward the high-value magnet rare earths, dramatically lifting material value while stripping out waste. Subsequent multi-flash runs are anticipated to further improve performance. We believe that our process offers what could become the first Western, chloride-based upgrading route for ionic-clay feedstocks."

This technology could dramatically reduce capital and operating costs, as well as deployment time frames, supporting the development of western supply chains.

Rare earth processing generally involves multi-stage solvent extraction, which can include hundreds or thousands of mixer-settler stages. However, the FJH technology delivers comparable results to these traditional methods but is faster, simpler and can be deployed modularly.

Developed at Rice University, Flash Metals USA has the exclusive licensing rights to the FJH technology.

This innovative approach is expected to transform the downstream processing of MREC, propelling the Caldeira rare earth project towards commercialisation and potentially reducing reliance on established offshore solvent extraction refineries.

The Caldeira project comprises 69 licences (with total landholdings over 193km²) in the south-west of Minas Gerais State in Brazil, close to the city of Poços de Caldas.

The project produces outstanding metallurgical recoveries depending on high-grade feed and by using a simple process with low technical risk and high environmental credentials. 

In March 2025, MTM Critical Metals signed an MoU with Vedanta, an aluminium production company, to explore alumina waste recycling.