West Cobar Metals Early Tests Suggest Shorter Leach Limits Aluminium Uptake
Key Takeaways
- In the 50 g/L acid test at ANSTO, scandium extraction rose only 1% from 6 to 24 hours while aluminium in solution climbed 94%.
- Aluminium is a major unwanted element in leach liquor, so a shorter leach that limits it may ease downstream purification.
- The figures are relative indices from a single 84 kg composite at 120ppm Sc, and solids assays, mass balances and repeatability are still outstanding.
- The 25 g/L test showed scandium still rising 18% by 24 hours, so the plateau is not consistent across acid strengths.
- Aircore drilling starts in late October 2026 on a 100 m x 50 m grid, alongside ALS beneficiation, bioleaching and scoping/PFS work, with no economics or resource change reported yet.
Scandium leach testwork delivers early results at Salazar
Early acid leach results from West Cobar Metals (ASX: WC1) suggest that more leaching time does not necessarily mean more scandium. In preliminary scandium leach testwork at ANSTO on the Salazar Critical Minerals Project in Western Australia, the company reported on 19 October 2026 that the relative increase in extraction from 6 hours to 24 hours was only 1% in the 50 g/L H2SO4 test.
Over the same timeframe, the concentration of aluminium in solution increased by 94%. Solids assays are outstanding, so the results are preliminary and subject to confirmation.
Aluminium is a major unwanted element in the leach liquor, so limiting how much dissolves may ease downstream purification. That is the opportunity the company is pointing to, subject to confirmation through the broader test program.
Matt Szwedzicki, Managing Director, West Cobar Metals
“…In the 50 g/L sulfuric acid test, limiting leach time to 6 hours significantly limits the aluminium extracted into solution while basically extracting the same amount of scandium as a 24 hour leach test – which is a very positive finding…”
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What the ANSTO results show
Leach time versus impurities
Early time-based observations suggest scandium leaching reaches a relative plateau after approximately six hours under the conditions assessed. The company says this may indicate an opportunity to limit extended leach residence times, subject to confirmation.
Aluminium is described as a major deleterious element in critical mineral leach liquors. In high concentrations it can impede downstream purification processes.
Preliminary leach data
The table below reproduces the Appendix 3 results from ANSTO. Values are relative indices based on liquor assays, with the 6-hour result set at 1 for each acid strength. There is no relativity between acid strength tests, and the figures do not show absolute extraction.
| H2SO4 (g/L) | Leach time (hrs) | Sc relative extraction | Al relative extraction | Fe relative extraction |
|---|---|---|---|---|
| 25 | 6 | **1** | **1** | **1** |
| 25 | 12 | **1.08** | **1.42** | **1.06** |
| 25 | 24 | **1.18** | **1.96** | **1.13** |
| 50 | 6 | **1** | **1** | **1** |
| 50 | 12 | **0.98** | **1.38** | **1.02** |
| 50 | 24 | **1.01** | **1.94** | **1.08** |
| 100 | 6 | **1** | **1** | **1** |
| 100 | 12 | **0.99** | **1.37** | **1.01** |
| 100 | 24 | **1.04** | **2.12** | **1.09** |
All tests ran at 80°C. The test basis was:
- Composite COMP09USAPAmph, made up of 19 one-metre aircore intervals from 3 holes
- Total composite weight of 84 kg
- ANSTO head assay of 120ppm Sc (184ppm Sc2O3), 15.5% Fe and 10.7% Al
The composite was selected using a 100ppm Sc cut-off. Results apply to this selected composite, and the source states that representativeness of the wider deposit is not demonstrated.
Why does leach optimisation matter?
Acid leaching dissolves metals out of crushed ore into a liquid solution, which is then processed to separate the metals. Any unwanted metals that dissolve alongside scandium, such as aluminium, can make that separation harder.
If a shorter leach captures a similar amount of scandium with less aluminium, it may simplify purification. Shorter residence times may also reduce equipment size and operating costs, although the announcement discloses no economics.
The ANSTO work is intended to combine with the ALS beneficiation program, announced on 15 October 2026, to inform an integrated processing flowsheet for Salazar.
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What are the next steps and catalysts?
The company listed its immediate priorities as:
- Aircore drilling, scheduled to begin in late October 2026 on a planned 100 m x 50 m grid to test higher-grade shallow zones and extensions
- Advancing front end beneficiation testwork underway at ALS
- Advancing metallurgical testwork, including scandium recovery potential, with the ANSTO program examining feed size, acid consumption and impurity dissolution
- Further bioleaching testwork
- Progressing integrated flowsheet demonstration and staged development studies (scoping / PFS)
- Continued engagement on potential U.S. funding and offtake pathways
For investors, that means several items of newsflow may be on the way across drilling, metallurgy and study work. The announcement reports no new drilling results, Mineral Resource changes or economic evaluation, so none should be assumed.
The confirmation theme runs through the release. Solids assays, mass balances and repeatability remain outstanding, and the relative indices cannot establish absolute extraction.
Ready to Learn More About West Cobar Metals’ Salazar Scandium Project?
Early ANSTO leach testwork at Salazar suggests a six-hour leach may capture similar scandium to a 24-hour leach while dissolving far less aluminium. With aircore drilling, beneficiation and further metallurgical work all on the horizon, newsflow across the project may be building.
Explore the Salazar Critical Minerals Project and the company’s next steps on the West Cobar Metals (ASX: WC1) company page. Results remain preliminary and subject to confirmation, so check back for the latest updates.