Rainbow Rare Earths - Further Major Advancement in Phalaborwa Test Work
RNS Number : 1279A
Rainbow Rare Earths Limited
22 September 2025
22 September 2025
Rainbow Rare Earths Limited
("Rainbow" or "the Company")
LSE: RBW
Further Major Advancement in Phalaborwa Test Work with Cerium Rejection Success
· Rainbow has achieved a further important advancement of the Phalaborwa test work via the successful incorporation of a cerium ("Ce") depletion step ahead of the final separation circuit
· This further enhances the quality of the high grade mixed rare earth product ("MREP")' recently announced, by reducing the Ce content in the MREP by ca. 65%
· It also reduces the volumetric flow for the mixed rare earth feed stream entering the final separation circuit, thereby positively impacting both capital and operating costs for this portion of the flowsheet
· This achievement demonstrates the unique IP and understanding developed by Rainbow of the recovery of rare earth elements ("REE") from phosphogypsum
· The Phalaborwa project is set to be a low-cost and responsible producer of both the critical light and heavy REE used in permanent magnets, which are vital to the green energy transition, defence and many other advanced technologies
NEWS ANNOUNCEMENT
Rainbow Rare Earths is pleased to announce further successful results from the ongoing test work for the Phalaborwa project in South Africa. This unique project encompasses the recovery and separation of REE from phosphogypsum stacks, a waste product from phosphoric acid production, meaning that many of the costs, risks and long timescales associated with traditional mining projects are eliminated.
Rainbow has been working on further optimising the feed stream to the final separation circuit via the incorporation of a Ce depletion step. This has successfully been achieved, benefitting both the quality of the exceptionally pure MREP recently announced, as well as the capital and operating cost outlook for the separation circuit.
George Bennett, CEO, commented: "This Ce rejection step is a major achievement in establishing Phalaborwa as one of the world's most efficient producers of light and heavy magnet REE worldwide, as it significantly simplifies the feed entering the final separation circuit, both in terms of volume and in terms of the amount of unwanted metal that must be separated. These results demonstrate the exceptional work being carried out by our team at our in-house facilities in Johannesburg, which is a world-class laboratory at the cutting-edge of REE recovery techniques."
Test Work Update
As previously announced, a key component of Rainbow's test work this year has been the delivery of a high grade, low impurity feed stream to the final separation process, as this is expected to be key to reaching separated rare earth oxides of the desired purity level.
Following the efficient impurity rejection work via CIX and the resultant recovery of an exceptionally pure MREP averaging >55% total rare earths oxide ("TREO") and with a TREO purity of >93%, Rainbow has been working on further optimising the feed stream to the final separation circuit via the incorporation of a Ce rejection step.
Ce is a low-value REE (valued at ca. US$1/kg) but it constitutes a large portion of REE material. Its early depletion ahead of final separation is therefore desirable as it reduces the flow and simplifies subsequent hydrometallurgical processes, thereby lowering the required reagent and water consumption, which results in a smaller separation plant with reduced capital and operating costs.
The incorporation of the Ce depletion step to the Phalaborwa flowsheet has helped to reduce the volumetric flow to the separation circuit to approximately 2% of the original 340 m3/h pregnant leach solution ("PLS") coming into the primary CIX circuit, and has the added benefit that there will be ca. 27% less metal going into the circuit that would need to be dealt with.
Rainbow has therefore achieved a major advancement in the Phalaborwa process by successfully reducing the amount of Ce in its exceptionally pure MREP by ca. 65%, further enhancing this high-grade product. These results have been confirmed via multiple tests.
Rainbow is now focused on finalising the separation component of the Phalaborwa flowsheet, which is set to produce a high purity neodymium and praseodymium ("NdPr") oxide and a SEG+ product, which will be a mix of medium and heavy REE, including the very high value dysprosium ("Dy") and terbium ("Tb"). Rainbow anticipates this workstream to be finalised in Q4 2025.
For further information, please contact:
| Rainbow Rare Earths Ltd | Company | George Bennett Pete Gardner | +27 (0) 82 652 8526 |
| IR | Cathy Malins | +44 (0) 7876 796 629 cathym@rainbowrareearths.com | |
| Tavistock Communications | PR/IR | Charles Vivian Eliza Logan | +44 (0) 20 7920 3150 rainbowrareearths@tavistock.co.uk |
| Berenberg | Broker | Matthew Armitt Jennifer Lee | +44 (0) 20 3207 7800 |
| Stifel | Broker | Ashton Clanfield Varun Talwar | +44 (0) 20 7710 7600 |
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