Rainbow Rare Earths Targets $916 Million Post-Tax Value at Brazilian Uberaba Project with Mosaic Partnership

Rainbow Rare Earths partners with Mosaic for the Uberaba project in Brazil, targeting high-margin rare earth extraction from waste with a 45% IRR.

By: AXL Media

Published: Mar 11, 2026, 5:54 AM EDT

Source: The information in this article was sourced from Mining Weekly

Expansion into Brazil Through Strategic Waste Processing

Rainbow Rare Earths has officially announced the results of an economic assessment for the Uberaba project in Minas Gerais, Brazil, marking a significant international expansion for the London-listed company. The development involves a partnership with Mosaic, a major US-based producer of phosphate and potash nutrients, to leverage existing industrial infrastructure. By focusing on the processing of phosphogypsum, a byproduct of phosphoric acid production, Rainbow intends to replicate the successful operational model of its flagship Phalaborwa project in South Africa. This waste-to-value approach allows the company to bypass the high costs and environmental complexities traditionally associated with primary rare earth mining.

Financial Projections and Industry Cost Positioning

The economic assessment outlines a highly profitable venture, estimating a post-tax net present value of $916 million and an internal rate of return of 45%. With an average annual EBITDA projected at $217 million over an initial 30 year life-of-mine, the project is expected to reach capital payback in just 1.7 years. According to Rainbow CEO George Bennett, these figures position Uberaba in the lowest-cost quartile for the global rare earth industry. The project is designed to handle a throughput of approximately 2.7 million tonnes of phosphogypsum annually, utilizing sampling data from Mosaic’s existing operations which indicates a head grade of 0.51% total rare earth oxide.

Technological Integration and Product Purity

The Uberaba facility will utilize proprietary intellectual property developed during the advancement of the Phalaborwa project's flowsheet. This technology is specifically designed to extract both light and heavy rare earth elements from secondary sources with high efficiency. The plant aims to deliver separated neodymium and praseodymium oxide, alongside a specialized SEG+ product rich in medium and heavy rare earth elements. Rainbow targets a purity level of greater than 99.5% for these critical materials, which are essential for high-tech applications and green energy transitions. Following extraction, the chemically cleaned phosphogypsum stream is returned to Mosaic’s facility, maintaining a circular industrial process.