Rainbow Rare Earths Forges Ahead with Second Major Venture, Partners with Mosaic on Brazilian Project

London-listed Rainbow Rare Earths (LSE:RBW) has taken a decisive step toward establishing a second major production hub, announcing a joint project development agreement with The Mosaic Company for its Uberaba rare earth elements (REE) project in Brazil. The move follows the publication of an economic assessment that pegs the project's post-tax net present value (NPV10) as high as $916 million.

"The results confirm that Uberaba represents a major opportunity to replicate the success we see at Phalaborwa," stated Rainbow CEO George Bennett. "It's positioned to be an additional high-margin, near-term development situated in the industry's lowest-cost quartile."

The technical study outlines robust economics for the venture, which plans to reprocess phosphogypsum—a by-product from Mosaic's existing fertilizer operations in Minas Gerais. Based on projected rare earth prices for 2026, the assessment forecasts a 45% post-tax internal rate of return (IRR) and an average annual EBITDA of $217 million, with capital payback expected within 1.7 years. Using a 13.5% discount rate, the post-tax NPV is estimated at $609 million.

At full capacity, the operation is designed to process approximately 2.7 million tonnes of material annually over an initial 30-year mine life. Steady-state production is targeted at 1,971 tonnes per year of neodymium-praseodymium (NdPr) oxide—a critical component for permanent magnets in electric vehicles and wind turbines—alongside 659 tonnes of a SEG+ heavy rare earth product. The project anticipates annual revenue of $319 million, with operating costs modeled at $38 per kilogram. Initial capital expenditure is projected at $279 million.

The partnership now advances to a pre-feasibility study phase. Should results be positive and both parties commit, they intend to form a joint venture, with Mosaic holding a 51% controlling interest and Rainbow owning 49%. The companies are targeting initial production by 2030.

Bennett highlighted the strategic synergy: "We are applying key learnings from Phalaborwa to accelerate Uberaba's development timeline. Mosaic has been an invaluable partner, bringing crucial technical expertise and a shared drive for innovation."

Analyst & Industry Reaction:

"This deal strategically de-risks Uberaba by securing both a feedstock source and a deep-pocketed partner," commented Michael Thorne, a resources analyst at Verity Capital. "It solidifies Rainbow's pipeline and addresses supply chain concerns for Western magnet manufacturers."

"It's a smart, circular economy play," noted Dr. Lena Schmidt, a mining engineer specializing in sustainable extraction. "Transforming waste into critical materials reduces environmental liability and enhances project economics. This model could set a precedent."

"Let's not get carried away. A study is just a study, and 2030 is a long way off," countered David K. Miller, a vocal independent investor on mining forums. "The NPV is highly sensitive to rare earth prices, which are notoriously volatile. This feels like hype to buoy the share price after recent sector weakness. Prove it with the feasibility study."

"For Brazil, this represents significant foreign investment and high-tech job creation in the mining sector," added Carlos Silva, a São Paulo-based industry journalist. "It aligns with the government's goals to add value to its mineral resources beyond traditional commodities."