Rainbow Rare Earths Ltd (LSE:RBW, OTC:RBWRF, FRA:RR1) CEO George Bennett spoke with Proactive's Stephen Gunnion about the start of the preliminary feasibility study (PFS) for the Uberaba rare earths project in Brazil with Mosaic, outlining work to further define the project's resource, processing characteristics and economics. Bennett said the PFS follows March's initial economic assessment, which showed "very, very strong economics" at spot rare earth prices, with the company on track for what it expects will be a positive PFS. He also discussed work by SRK to prepare a maiden JORC mineral resource estimate for Uberaba. Mosaic holds a large phosphate resource feeding its phosphoric acid plant there, and Rainbow has identified rare earths in the associated phosphogypsum, grading around 5,100 ppm total rare earth oxides. The resource work will assay existing core and review historical data to confirm consistency, with Bennett suggesting this could establish Uberaba as a very long-life project. The current study covers one phosphoric acid production line, with potential for a second. Bennett also explained why Mosaic is sending another six tonnes of phosphogypsum for pilot testing, examining factors like leach residence time and temperature, drawing on IP developed through Rainbow's Phalaborwa project. On economics, Bennett highlighted March's assessment showing a $916 million NPV and 45% IRR: "We expect the PFS will deliver very, very strong economic numbers," with completion targeted for the second half of 2027 ahead of a potential definitive feasibility study and construction. Visit Proactive’s YouTube channel for more interviews and company updates. If you found this video useful, give it a like, subscribe to the channel and enable notifications for future content. Read Proactive's Editorial Policy here: https://www.proactiveinvestors.co.uk/pages/editorialPolicy #RainbowRareEarths #Uberaba #RareEarths #CriticalMinerals #Mosaic #RareEarthElements #Mining #BrazilMining #Phosphogypsum #JORC #PreFeasibilityStudy #PFS #MiningInvestment #CriticalMaterials #InvestorNews #Proactive