West Cobar Metals (ASX:WC1) has identified scandium potential at its Salazar rare earth element (REE) and co-products project in Western Australia.
“The scandium contained within our Salazar project is very exciting because it is high grade, pervasive and historical testwork shows excellent leaching recoveries are achievable at atmospheric pressure,” Managing Director, Matt Szwedzicki, said.
“Scandium is a highly sought after critical mineral with scandium oxide prices at nearly 1 million US dollars per tonne. Recent interest in the metal by Rio Tinto reinforces our view that the scandium enhances the opportunity to commercialise our unique clay hosted project.”
Salazar Project
West Cobar has been focused on validating the conceptual flowsheet and one of the key products of interest is scandium, which is an exceptionally valuable and rare mineral present in high grade zones within the Salazar project.
There are very few sources of scandium supply globally and it is predominantly used for enhancing the characteristics of aluminium alloys and in solid oxide fuel cells.
In what may be perceived as an indication of the growing strategic interest in the metal, Rio Tinto Ltd recently purchased the Owendale scandium deposit in NSW and has established a dedicated scandium business unit.
A number of Australian scandium deposits are hosted in lateritic formations, which makes the Salazar project distinct because the scandium is hosted in saprolite clays making it potentially easier and cheaper to recover. The Newmont deposit contains widespread high grade scandium mineralisation, with intercepts of up to 3m of 423ppm Sc.
Scandium Uses and Prices
Scandium is a lightweight soft metal used in alloys and Solid Oxide Fuel Cells (SOFC), the aerospace and defence industry, lighting, electronics, ceramics and 3D printing amongst other uses.
When alloyed with aluminium, scandium significantly strengthens the aluminium alloys and enables them to be reliably welded leading to reductions in manufacturing costs. This factor is a significant aspect of aircraft manufacturing where 0.1% to 0.5% scandium in the aluminium alloys has a significant impact on the resulting strength of the alloy as well as a significant weight reduction of the aircraft. This in turn leads to less CO2 produced per air mile and more efficient aircraft with higher payload capacity.
Scandium plays an important role in enhancing the performance and efficiency of SOFCs, which are devices that convert chemical energy into electrical energy.
SOFCs use hydrogen or hydrocarbon fuels and oxygen to produce electricity, making them suitable for various applications, such as power generation and industrial processes.
A benefit of adding scandium to the zirconia-based electrolyte in SOFC’s is that it lowers the operating temperature of the SOFCs compared to conventional high-temperature SOFCs.
Lowering the operating temperature has several advantages, such as reducing thermal stress on cell components and extending cell lifespan. Solid Oxide Fuel Cells represent a key source of demand growth for scandium in the near term and are aligned to a low carbon world.
Scandium is a high value critical metal, scandium oxides are currently priced at US$847 – 875 per kg (equivalent to US$847,000/t to US$875,000/t).
Prices for 99.99% pure scandium have fluctuated between US$4,000 and US$20,000 per kilogram (equivalent to US$4,000,000/t to US$20,000,000/t) over the past decade .
Scandium Demand
The current scandium market is small with approximately 20 to 30 tonnes in demand for 20222, however forecasters are predicting strong growth due to the metal’s unique properties. Much more widespread usage of scandium is believed to be constrained by limited global supply.
As an example, if 0.1% of the annual global aluminium production was alloyed with 0.5% scandium, it would result in an annual global scandium demand of 345 tonnes, which is 11x the current demand.
Scandium Mineralisation at Salazar
Scandium enrichment in saprolite is predominantly found enclosed within the Newmont REE estimated Mineral Resource 5 where it is derived from underlying amphibolite.
Historical drill data shows that the amphibolite bedrock contains 20 to 78 ppm Sc. It is locally enriched in the overlying clay saprolite where it appears to form a more leachable mineralogy. It closely follows the TiO2 mineralisation that is also spatially related to the amphibolite within the saprolite
Metallurgical Testwork
Historical testwork shows that scandium at the Newmont deposit might be more amenable to extraction at much lower temperatures and pressures than typical lateritic deposits.
Metallurgical diagnostic and sighter leach tests were completed by Bureau Veritas Minerals (Amdel) and Nagrom. A total of 165 micro leaches were completed using SAC1 12-24m as the test composite. The leach programs were initially established to assess REE and alumina leach characteristics, scandium was analysed at each stage as part of the total assay suite.
The range of parameters tested to identify the optimum leach conditions during these tests included lixiviants, leach times, pulp density, leach temperature with variations across all parameters.
The historical leach tests show that Newmont scandium is readily leached at atmospheric pressures and whilst a range of temperatures and lixiviants have been tested, relatively low temperatures achieved good results.
Sizing analyses by Nagrom on scandium enriched (102ppm Sc) saprolite in SAC1 12-24m at Newmont shows enrichment of scandium (113ppm Sc) in the finer fractions (<75μm).
Scandium processing could form part of the overall Salazar Project process flowsheet below which would provide an integrated processing flowsheet recovering TiO2, REEs and scandium.
The Salazar Project (consisting of both the Newmont and O’Connor deposits) is situated in the Esperance district approximately 120km north-east of the township of Esperance and all tenements are located on non-agricultural undeveloped state land.
With a total area of 1,171 sq. km, the project features some of the highest grade saprolitic clay- hosted REE and co-product resources discovered in Australia.