Rainbow Rare Earths Advances Phalaborwa Project with Key Flowsheet Milestones

Rainbow Rare Earths Ltd (LSE:RBW) has reported significant progress on its Phalaborwa rare earths project in South Africa. The company announced that three-quarters of the project's process flowsheet has been finalized and has now moved into the engineering phase of the definitive feasibility study (DFS).

This update follows successful pilot plant operations in the first half of 2026, with the data gathered now informing the DFS design. Test work conducted at Rainbow's Johannesburg laboratory has led to a simplified flowsheet. Key optimizations include replacing hydraulic reclamation with mechanical reclamation, eliminating the weak acid leach circuit, reducing the counter-current leach stages from three to two, and decreasing residence time from 32 to 8 hours. The number of capital-intensive horizontal belt filters has also been reduced from 14 to 8.

Furthermore, Rainbow has transitioned from continuous ion chromatography to solvent extraction, a proven industry-standard separation process. This circuit concentrates rare earth elements ninefold, significantly reducing flow rates into subsequent processing stages.

Dave Dodd, Technical Director at Rainbow, confirmed the successful finalization of the flowsheet, which now delivers a mixed rare earth feed to the SX separation process. The Phalaborwa project aims to be the first commercial recovery of rare earth elements from phosphogypsum, a waste product of phosphoric acid production. The final circuit is expected to yield high-purity NdPr oxide and SEG+ Group, along with commercial quantities of dysprosium, terbium, and yttrium.