The Sybella Project: Rare Earth Elements, Mount Isa Inlier, QLD
Our Sybella rare earth oxide (REO) discovery is unique, being a granite-hosted deposit type with positive characteristics that stand it apart from clay-hosted and monazite dominated REO deposits. The REO-enriched granite target at Sybella is over 12 kilometres long and 3 kilometres wide starting from surface which offers very large tonnage potential ,and is well located just 20 kilometres southwest from the city of Mount Isa (Figure 1). Early-stage drilling, metallurgical and comminution studies have added to our confidence that a low-cost, low-capital, heap leach processing option may prove feasible.
Initial RC drilling in 2023 discovered wide intervals of granite-hosted REO mineralisation at relatively high grades starting at surface. Analysis of step-out drilling covering an 8.4 kilometre by 3 kilometre portion of the REO enriched granite enabled the definition of a large maiden Inferred Mineral Resource Estimate (Figure 2, refer Red Metal ASX announcement dated 21 October 2024).
The Mineral Resource Estimate defined very large tonnages at good Magnet Rare Earth Oxide (MREO) grades that start at surface and remain open below 100 metres, including :
- 795 Bt at 302 ppm NdPr, 28 ppm DyTb (using a 200 ppm NdPr cut-off grade)
This total resource, when constrained geologically, includes significant at surface Inferred Mineral Resources of Weathered Granite that represent advantageous early mining opportunities and includes:
- 788 Mt at 297 ppm NdPr, 28 ppm DyTb (using a 200 ppm NdPr cut-off grade)
Infill drilling to an Indicated Mineral Resource status was initiated during FY2025, however, a large bush fire on the project delayed activities and the planned program was only partially completed.
Importantly, the total MREO grades and widths from the infill drilling are consistent with results from adjacent drill traverses 400 metres to the north and south adding to our confidence in the Inferred Mineral Resource.
Large area composite samples of drill chips derived from the infill program and the initial drilling program were collected for bottle roll pH optimisation leach tests on Weathered Granite and Partially Weathered Granite to a depth of 24 metres.
Optimum economic REO leach extractions were achieved in the pH 1.7 to pH 2.5 range highlighting key leach parameters for the pending column leach test work. The bottle-roll optimisation leach tests at pH 2.0 for a large portion of the weathered Kary Zone ores achieved:
- Neodymium extractions ranging 76-81%
- Praseodymium extractions ranging 76-81%
- Terbium heavy rare earth extractions ranging 43-60%
- Dysprosium heavy rare earth extractions ranging 38-55%
- A low sulphuric acid consumption ranging 17-22 kg H2SO4 /tonne
- Very low iron extraction ranging 1-2% resulting in very low residual iron levels
- Low aluminium extraction ranging 3-6% resulting in low residual aluminium levels.
The new data have validated and significantly improved on past results and point to the opportunity to further maximise leach outcomes by adjusting the acid strength over time.
Encouraged by the successful bottle roll tests, nine large diameter PQ diamond core holes were drilled over the Kary Zone providing coarse, non-pulverised, weathered and fresh granite rock samples specifically for column leach test work. Spectral mineral scans using the Geological Survey of Queensland’s Hylogger system were completed on five of the holes to quantify key mineral boundaries ahead of the metallurgical sampling.
The column leach tests will best simulate an actual heap leach setting and will use the optimised acid leach parameters determined from the bottle roll experiments to the coarsely crushed diamond core samples. Findings from the column leach tests are anticipated toward the end of 2025.
Recently (ASX announcement 17 November 2025) Red Metal announced breakthrough results from innovative trials on the use of Ion Exchange (IX) resins and initiated the much anticipated, large column heap leach tests on a range of coarsely crushed rare earth ore types.
The successful IX trials were able to more efficiently enrich the rare earth content and separate impurities from the Pregnant Leach Liquor derived from weak-acid leaching of the Sybella ores.
Importantly, the IX trials clearly show that we can replace the standard two-stage impurity removal process with a simple IX process (refer to Red Metal ASX announcement dated 18 November 2025) which offers significant capital and operating cost advantages, higher REE recoveries and reduced flowsheet complexity.
The ongoing column heap leach tests and ion exchange studies, comprehensive comminution research, together with planned infill drilling to an Indicated Resource level, will provide the key data necessary to advance the Sybella project towards Pre-Feasibility work in 2026.
With strong rare earth oxide demand forecast into the future and rare earth supply constrained both geopolitically and from limited Western World mine production, we remain very optimistic about future prices for magnet rare earth elements.
[Figure 1] Sybella Project: Red Metal drill hole locations (black dots) on satellite imagery overlain by a colour image of the average grade of NdPr oxide to 60 metre down-hole.
[Figure 2] Sybella Inferred Mineral Resource Estimate: Block model level plan showing variation in NdPr oxide block grade values from surface to 6 metres. No other rare earths are included in this particular depiction. Grid is 800 metre by 800 metre. Refer to Red Metal ASX announcement date 21 October 2024 for Inferred Mineral Resource details.