Mount Ridley grabs global scandium crown with 946Mt WA resource

Mount Ridley Mines has super-sized its scandium footprint at Grass Patch near Esperance in Western Australia, lifting the inventory to 946 million tonnes and claiming the global crown for the largest publicly reported JORC-compliant resource for the metal as its home-grown processing technology gathers momentum.

The new inferred resource runs at 50.1 parts per million (ppm) scandium for 47,357 tonnes of contained metal, or 72,637t of scandium oxide, using a 25ppm cut-off. It spans more than 25km of strike, averages 3.5km wide and reaches from surface to 70m depth.

At the southern end lies Block 1, home to Mount Ridley’s maiden 367.98Mt scandium resource unveiled in January and the starting point for this year’s resource-growth push.

Rather than launch an expensive drilling blitz, the company effectively mined its existing data. Phase one of its 2026 re-assay program sent 3271 stored pulp samples from historical aircore and diamond drilling back to the laboratory, revealing broad, near-surface scandium beyond previous resource boundaries.

With those assays folded into the update, Block 1 now stands at 367.45Mt at 50.3ppm scandium for 18,475t of metal. Further north along the same geological corridor, the larger Block 2 contributes 578.63Mt at 49.9ppm for 28,882t.

Together, the separately modelled areas cover about 44.5 square kilometres and make up the 946Mt resource. The model draws on 410 historical aircore and diamond holes totalling 14,828m, with many ending in scandium and leaving the system open laterally and at depth.

Adding another string to the bow, the two areas also host 122.5Mt of heavy rare earths resources and 536.2Mt of gallium resources. The wider project’s gallium inventory stands at 838.7Mt.

The company says that co-location of the metals could simplify material handling and shared processing, potentially cutting capital and operating costs. Its wholly owned, patent-pending Selectro hydrometallurgical leach process is designed to extract scandium, heavy rare earths and gallium from the same feed through a single circuit.

We’ve now established the world’s largest publicly reported JORC-compliant scandium resource, at a time when the commodity is under intense focus from governments and industry seeking to secure supply outside China.

With phase one baked into the 946Mt resource, Mount Ridley has kicked off phase two re-assaying across Grass Patch to chase extensions. Density testing is underway to support potential upgrades into higher-confidence resource categories.

Flotation testwork will assess whether valuable minerals can be concentrated before leaching, after TIMA analysis identified rare earth-bearing phosphate minerals that could respond well to flotation. Engineering firms are also discussing a scoping study to help design and cost a demonstration plant to test the process at a larger scale.

Selectro has already returned 80 per cent scandium recovery in first-pass laboratory work while simultaneously extracting heavy rare earths and gallium. Mount Ridley says larger-scale work is needed to establish commercial economics, with the potential to use the technology at Grass Patch, license it to third parties or pursue both.

The company will also test its chemistry on other deposits and metals to explore applications beyond Grass Patch. Its processing ambitions gained extra firepower in July when metallurgist Chris Larder was appointed inaugural chief technology officer, alongside research links with Oak Ridge National Laboratory, Lawrence Livermore National Laboratory and Germany’s Fraunhofer.

There is plenty of dirt left to interrogate. Approximately 80 per cent of the tenure remains untested and seven gravity targets coveranother 33km of strike. Grass Patch sits 25km northeast of Esperance, with a nearby deep-water port, road and power infrastructure providing an advantage over more remote critical minerals projects.

Scandium earns its strategic stripes in lightweight aluminium alloys used in aerospace and defence, as well as in solid oxide fuel cells. Primary production is scarce and supplemented by inventories and secondary sources, putting new Western supply firmly in the spotlight. This was underscored earlier in the month by a US$400M conditional loan commitment from the US Department of War to Sunrise Energy Metals’ Syerston scandium project.

Mount Ridley has spent 2026 proving Grass Patch is big while building proprietary processing technology around its multi-metal hand. With 946Mt of scandium on the books and a potential processing ace in Selectro up its sleeve, the game appears to be shifting from proving how much is there to proving just how valuable it could be.

Is your ASX-listed company doing something interesting? Contact: matt.birney@wanews.com.au