Australia’s St George Mining has signed a memorandum of understanding (MoU) with Técnicas Reunidas covering processing test work on rare earth samples from the Araxá deposit in Brazil's Minas Gerais state.

The Spanish company will carry out the initial work using its RARETECH technology to refine rare earth mineralisation.

This includes producing mixed carbonates and rare-earth oxides, along with the separation and fractionation of rare earth elements (REEs).

St George Mining owns the entire Araxá deposit, which is the largest hard rock rare earths deposit in South America.

The agreement with Técnicas Reunidas involves using its technology to process rare earth concentrates into carbonates.

Técnicas Reunidas brings expertise in critical raw material recovery, having deployed RARETECH in projects across the US, Japan, Australia and other countries.

RARETECH was developed by Técnicas Reunidas through its In-House Technology Development Division and Technology Centre, focusing on the recovery, processing and refining of critical minerals, essential metals and other circular economy products.

In late February, the company also secured an agreement with Australian company Osmond Resources to supply RARETECH technology for the EU's first comprehensive rare earth production project, which spans more than 220km² in northern Jaén, Spain.

Técnicas Reunidas may also provide further assistance to St George Mining, including designing a flow diagram and an industrial plant for processing rare earths, among other tasks.

St George Mining aims to leverage this alliance to enter European markets following previous partnerships with companies such as REalloys in the US and MagBras in Brazil.

St George Mining CEO John Prineas said: “We are very excited to be working with Técnicas Reunidas to further assess the optimal processing route for the Araxa rare earths.”

In December 2024, the company announced partnerships to advance downstream production of niobium and REEs from the Araxá project.