Work Underway On Cowalinya Rare Earth Project

Heavy Rare Earths Limited (“HRE” or “the Company”) has today commenced a program of analytical and metallurgical test work on samples from its Cowalinya clay-hosted rare earth deposit in the Norseman-Esperance region of Western Australia.

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• Commenced a program of analytical and metallurgical test work
• Re-assaying samples after fusion methods demonstrated an average increase of 12.2% in total rare earth grade
• Reporting of re-assay results expected to begin in late-September 2022
• Commencing metallurgical work to validate previous results and build on these with a comprehensive metallurgical program

Analytical (Re-Assay) Program

Mineral Resources were estimated at Cowalinya in December 2021 using 859 assay samples from 109 air core holes drilled in July 2021. These assays were done by 4-Acid Digest/ICP-MS.

HRE subsequently selected 61 one metre samples from two holes (AC16 and 28) for assay using Lithium Borate Fusion/ICP-MS. This was done to compare the effectiveness of this methodology to report all rare earths (‘total digest’) versus rare earths contained in acid- soluble mineral species only (‘near total digest’), and provided a useful check of the primary 4-Acid Digest/ICP-MS assays.

Forty (40) of the 61 samples submitted for assay by Lithium Borate Fusion /ICP-MS contained >300ppm TREO-CeO2, the cut-off grade for the Cowalinya resource. Re-assay of these 40 samples delivered an average increase in total rare earths of 12.2%. This result led to the Competent Person (“CP”) for Mineral Resources recommending that HRE use Lithium Borate Fusion/ICP-MS for future programs at Cowalinya.²

HRE has adopted the CP’s recommendation and, in anticipation of a revised resource base arising from an expanded drilling footprint at Cowalinya, earlier this week delivered 729 two- metre composites from 102 of the 109 air core holes drilled at Cowalinya in 2021 to LabWest Minerals Analysis (“LabWest”) in Perth for assay by Lithium Borate Fusion/ICP-MS. The first batch of assays from this program is expected to be reported by LabWest in late-September 2022.

Metallurgical Program

In 2021 HRE completed leach tests on 40 mineralised saprolite drill samples from three holes (AC16, 28 and 41) at Cowalinya which involved the use of hydrochloric acid (HCl) at different concentrations (2-20% w/w) and at a range of temperatures (20-50°C). The resonance time for each test was 24 hours. This work demonstrated that for Cowalinya material substantial proportions of rare earths could be brought into solution, averaging approximately 91% of total rare earths (or 88% of the valuable magnet rare earths praseodymium, neodymium, terbium and dysprosium) at 30°C and 5% w/w HCl.³

To build on these encouraging results, HRE has engaged Perth-based Strategic Metallurgy (“Strategic”) to both validate these sighter tests and design and undertake a comprehensive metallurgical program, initially involving particle size analysis as the basis for gangue rejection. This will be followed by a series of batch tests to examine the influence on leaching performance of parameters such as resonance time, temperature, acid type and concentration, and slurry density. Observation as to reagent consumption, metal recovery and solution composition, including impurity deportment, will be considered to establish a suitable leach regime.

HRE has delivered 13 samples to Strategic from ten drill holes (AC4, 16, 28, 36, 41, 47, 57, 69, 89 and 104) across the Cowalinya deposit as the basis for first-pass metallurgical work. Each sample is a five-metre composite of mineralised upper or lower saprolite horizon for which final head assays are in the process of being determined by LabWest (likely approximate range 320-1450ppm TREO).

Key outcomes of the metallurgical program will be communicated to the market in the weeks and months ahead as material results come to hand.

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