Rainbow Rare Earths Ltd (LSE:RBW, OTC:RBWRF) has inked a memorandum of understanding with an industry leader that it said represents a major opportunity to advance a project in Brazil.
The agreement is with Mosaic Company, described by Rainbow as “the world's leading integrated producer of concentrated phosphate and potash”, and it sets out a potential collaboration to jointly develop a process flowsheet to extract the rare earth elements from the Uberaba project, in the Minas Gerais region.
The Uberaba phosphogypsum material is similar to Rainbow's Phalaborwa project in South Africa, Rainbow explained in a statement.
The company elaborated that like Rainbow’s Phalaborwa, the Uberaba project is based on a hardrock carbonatite phosphate deposit, that initially produces a phosphate slurry feed which is then processed into phosphoric acid – whilst the hardrock initially does not contain rare earths in sufficient quantities the processing plant concentrates the quantity of rare earths.
Moreover, the resulting product – a 'cracked' chemical phosphogypsum material – has the benefit that it can render the rare earths associated with the phosphogypsum amenable to direct acid leaching.
It can mean that simpler hydrometallurgical processes can produce separated and purified rare earth oxides.
In the Brazilian venture, Rainbow anticipates that the majority of the Phalaborwa front-end process flowsheet will be applicable at Uberaba along with Phalaborwa back-end process flowsheet.
Using these insights Rainbow and Mosaic expect to collaborate on the production of a preliminary economic assessment of the opportunity to extract rare earths.
“Innovation and sustainability are critically important to Mosaic and that's why we are enthusiastic about the opportunity to work with Rainbow to explore the extraction of rare earth oxides from our gypsum stack,” said Mosiac senior vice president Corrine Ricard.
George Bennet, Rainbow chief executive, meanwhile, added: "This agreement with Mosaic represents a major opportunity for Rainbow to apply the proprietary extraction technology developed in conjunction with K-Tech to become a multi-asset producer of rare earth elements from secondary sources.
“The geographic diversification of our portfolio further de-risks Rainbow as one of the only rare earth development companies with multiple near-term production opportunities and aligns with our aim to be a forerunner in the establishment of an independent and ethical supply chain of the rare earth elements that are driving the green energy transition."