Australian-based St George Mining has followed up this week’s rare earths technology deal with Spain’s Tecnicas Reunidas with an agreement to assess Boston Metal’s Molten Oxide Electrolysis technology on niobium from its Araxa project in Brazil.
Boston Metal, which has secured more than US$500 million of private investment from BHP, BMW, Microsoft and other heavyweight backers, was named by TIME Magazine on its 2025 Best Inventions List for its patented MOE technology developed at the Massachusetts Institute of Technology (MIT) and commercialised by Boston.
ASX-listed St George, which has a current market value around A$425 million, said the two companies would “trial niobium production efficiencies” using the Boston Metal process and assess its potential application for ferroniobium production under a memorandum of understanding.
Boston is currently commissioning its first commercial plant in Brazil.
St George acquired Araxa early in 2025 and by April had put out a maiden niobium and rare earth element mineral resource estimates of 41.2 million tonnes grading 0.68% niobium pentoxide and 40.6Mt at 4.13% total rare earth oxide.
“The MOE technology offers the opportunity for St George to develop a new generation of niobium processing at Araxa,” St George executive chairman John Prineas said.
Under an MoU with Tecnicas Reunidas, St George also plans to test the suitability of the Spanish engineering group’s RARETECH rare earths technology for processing REs from Araxa. Testwork on samples of the rare earths resource at Araxa could lead to a broader engineering and construction services alliance with the US$2.75 billion Madrid-based group.
Tecnicas Reunidas was last year selected to lead the European Commission’s PERMANET (PERmanent MAgnet Network for the European Transition) project aiming to create a new permanent magnet value chain – including processing and refining of rare earths and recycling – in Europe.
Tecnicas Reunidas said it had “proven experience in this field as it already supplies the market with its own technology, RARETECH, which allows obtaining rare earth concentrates in the form of carbonates from ores”.
“The reputation of Tecnicas Reunidas in Europe is second to none regarding rare earths processing and we are very pleased to be able to access their expertise to further develop our downstream processing strategy for our Araxa rare earths,” Prineas said.
“Our Araxa project already boasts the largest hard-rock rare earths deposit in South America and is larger than the leading rare earths mine in the US, the Mountain Pass mine in California, that has attracted significant funding from the US government and US private companies.
“The sheer volume of our rare earths deposit provides an opportunity for St George to deliver into supply chains around the world, including Brazil, the US and Europe.
“With strategic downstream alliances already forged in Brazil and the US we are delighted at the opportunity to potentially also access rare earths markets in Europe through our alliance with Tecnicas Reunidas.”
St George said it was negotiating a fee for the Tecnicas Reunidas testwork.
“Should the chemical and metallurgical test work demonstrate the viability of RARETECH for the Araxa project the parties agree to negotiate in good faith the terms of a licence agreement for use of that technology,” the company said.
