LONDON, UK: Rainbow Rare Earths Limited (AIM: RBW), the rare earth element mining company, has announced that it has signed a memorandum of understanding (MOU) with The Mosaic Company (NYSE: MOS), the world’s leading integrated producer of concentrated phosphate and potash, to jointly develop a process for extracting rare earth elements from Mosaic’s phosphogypsum stack in Uberaba, Minas Gerais, Brazil.

Phosphogypsum is a by-product of phosphoric acid production, which is used to make fertilizers. Phosphogypsum contains valuable rare earth elements, which are essential for many high-tech applications, such as electric vehicles, wind turbines, and smartphones.

Rainbow and Mosaic will collaborate on developing a process flowsheet and conducting a preliminary economic assessment of the rare earth extraction opportunity from the Uberaba stack, which is based on a hardrock carbonatite phosphate deposit similar to Rainbow’s Phalaborwa project in South Africa.

Rainbow expects the Uberaba stack to have a similar grade and rare earth element make-up as those at Phalaborwa, where Rainbow has developed a proprietary technology in partnership with K-Technologies, Inc. (K-Tech) to produce separated and purified rare earth oxides. Rainbow has the exclusive rights to use the K-Tech technology for Brazil.

George Bennett, CEO of Rainbow, said: “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 critical minerals.”

What is Memorandum of Understanding (MoU)