Technical Report on Phalaborwa Process Flow Sheet

23 August 2022

Rainbow Rare Earths Limited

("Rainbow" or "the Company")

LSE: RBW

Release of Technical Report on Phalaborwa Processing Flow Sheet

Rainbow Rare Earths has released an updated Technical Report on the processing flowsheet to extract rare earth elements from the phosphogypsum stacks at the Company's Phalaborwa Project in South Africa ("the flowsheet"), which is available on the Company's website at www.rainbowrareearths.com/investors/results-reports-presentations/ .

The flowsheet has been developed in parallel with K-Technologies, Inc., USA ("K-Tech") and represents a breakthrough in allowing for the economic extraction of rare earth elements from phosphogypsum, which has historically proven to be challenging.

Compared to the initial processing options considered when work commenced, a number of key enhancements have been made, resulting in significant anticipated capital and operating cost savings for the Phalaborwa Preliminary Economic Assessment ("PEA") which is currently being finalised.  As detailed in the Technical Report, the flowsheet for the PEA will comprise the following key steps:

·    Phosphogypsum will be reclaimed hydraulically from the existing stacks and pumped to the processing facility removing soluble impurities prior to the leach process.

·    A fluoride leach regime will be employed to remove fluoride from the gypsum stream, allowing rare earth grades in the pregnant leach solution to be maximised and producing reagents from the fluoride for use elsewhere in the processing circuit, reducing operating costs.

·    The fluoride leached phosphogypsum progresses to a rare earth counter current sulphuric acid leach system for the extraction of the target rare earth elements.  This allows for successful recycling of the various acid streams to optimise the overall processing costs.

·    A rapid consolidation process for the rare earths in the pregnant leach solution allows the rare earths to be concentrated with primary impurity rejection.  This process replaces the originally anticipated nano filtration system, which significantly improves the overall acid recycling, thereby reducing operating costs.

·    The rapid consolidation process feeds the downstream continuous ion exchange and continuous ion chromatography processes to deliver separated rare earth oxides.  The flow rates to these processes are considerably lower than anticipated using nano filtration techniques resulting in significant capital and operating cost savings.

Work is now ongoing to finalise the Phalaborwa PEA, which is expected to be completed at the end of September / early October 2022.

Rainbow and K-Tech anticipate the potential for wider application of this innovative processing flowsheet than solely the Phalaborwa Project.  As a result, Rainbow and K-Tech are jointly applying for international patents.  Rainbow is in the process of identifying global projects where the technology could be used to unlock further sources of rare earths from phosphogypsum.

Rainbow Rare Earths CEO, George Bennett, commented: "We are delighted to provide technical detail which emphasises the breakthrough that has been delivered by Rainbow, in conjunction with our partners K-Tech, in delivering a processing flowsheet to economically extract rare earth elements from phosphogypsum.

Working alongside our partners at K-Tech we have continually seen opportunities for refinement and optimisation as the flowsheet has developed.  We anticipate that this process will continue as we progress from the PEA to PFS and BFS at Phalaborwa, alongside test work at other phosphogypsum opportunities, giving scope for both capital and operating cost reductions from the Phalaborwa PEA.

We believe that this work further demonstrates Rainbow's ability to overcome the historical technical, environmental, and economic challenges related to extracting rare earths from phosphogypsum, enabling us to unlock a valuable, near-term source of permanent magnetic metals required so urgently to drive the global green energy revolution."

**ENDS**

Market Abuse Regulation ("MAR") Disclosure

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR"), and is disclosed in accordance with the Company's obligations under Article 17 of MAR.

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Notes to Editors:

Rainbow's strategy is to become a globally significant producer of rare earth metals. NdPr and Dy are vital components of the strongest permanent magnets used for the motors and turbines driving the green technology revolution. Analysts are predicting demand for magnet rare earth oxides will grow substantially over the coming years, driven by increasing adoption of green technology, pushing the overall market for NdPr and Dy into deficit.

The Phalaborwa Rare Earths Project, located in South Africa, comprises an Inferred Mineral Resource Estimate of 38.3Mt at 0.43% TREO contained within gypsum tailings stacked in unconsolidated stacks derived from historic phosphate hard rock mining. High value NdPr oxide represents 29.1% of the total contained rare earth oxides, with economic Dysprosium and Terbium oxide credits enhancing the overall value of the rare earth basket in the stacks.  The rare earths are contained in chemical form in the gypsum stacks, which is expected to allow high-value separated rare earth oxides to be produced with lower operating costs than a typical rare earth mineral project.

The Company's Gakara Project in Burundi has produced one of the highest-grade rare earth concentrates in the world (typically 54% TREO) through trial mining operations. The Gakara basket is weighted heavily towards NdPr, which account for approximately 19.5% of the contained TREO and 85% of the value of the concentrate. The Gakara project is currently on care and maintenance at the request of the Government of Burundi.