Mount Ridley Mines (ASX:MRD) upgrades Grass Patch scandium resource
Mount Ridley Mines has reported an upgraded JORC 2012 Inferred Scandium Mineral Resource at its Grass Patch Project, located 25km northeast of Esperance in Western Australia.
The update follows the systematic re assaying of historical drill pulps from exploration programs completed between 2014 and 2022.
Highlights
Inferred Mineral Resource of 946Mt at 50.1 ppm scandium, or 76.8 ppm Sc₂O₃, using a 25 ppm scandium cut off.
Contained metal totals 47,357t of scandium and 72,637t of Sc₂O₃.
The estimate is supported by 410 aircore and diamond drill holes covering 14,828m.
Phase 1 included the re assaying of 3,271 historical aircore and diamond drill pulp samples.
Selectro™ Test 2 achieved 80.0% scandium recovery from the tested composite.
Phase 2 re assaying is continuing across the Grass Patch Complex.
The increase in the Mineral Resource Estimate was primarily driven by the re assaying of existing drill pulps rather than additional drilling.
Historical data retained from earlier nickel, copper and rare earth exploration programs identified scandium enrichment within the weathered saprolite and clay profiles.
The estimate comprises Block 1 and Block 2, which are located along the same geological corridor within the Grass Patch Complex.
Mineralisation extends for more than 25km in strike, has an average width exceeding 3.5km and occurs from surface to approximately 70m depth.
Block 1 contains an Inferred Scandium Mineral Resource of 367.45Mt at 50.3 ppm scandium, containing 18,475t of scandium metal and 28,337t of Sc₂O₃.
The company reported that mineralisation is shallow and broadly distributed within the weathered profile, with the resource remaining open to the southwest for approximately 4km.
Block 2 contains an Inferred Scandium Mineral Resource of 578.63 Mt at 49.9 ppm scandium, containing 28,882 t of scandium metal and 44,300 t of Sc₂O₃, with further reassaying underway to evaluate extensions beyond the current resource boundaries.
Scandium mineralisation is co located with Mount Ridley’s previously reported 122.5Mt heavy rare earth and 536.2Mt gallium Mineral Resources within Blocks 1 and 2.
The broader project hosts a total Gallium Mineral Resource of 838.7Mt, including 302.4Mt within Block 3.
Mount Ridley Managing Director and Chief Executive Officer Allister Caird said:
“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.”
The company’s Selectro™ Process is being developed as a single feed, multi commodity hydrometallurgical process for rare earth elements, scandium and gallium.
Initial testwork was conducted independently by Nagrom on approximately 90g dry weight aliquots from a 16.8kg homogenised composite prepared from selected intervals from 5 historical diamond drill holes.
Selectro™ Test 2 recovered 80.0% of the scandium from the tested composite over 24 hours, compared with 27.6% from the hydrochloric acid baseline test.
The announcement states that the differing operating conditions and small laboratory scale mean the results should not be interpreted as establishing commercial process economics or project wide metallurgical recoveries.
The results relate only to the tested composite and have not been extrapolated across the entire Grass Patch resource.
Mount Ridley is in discussions with multiple engineering firms regarding a scoping study to inform the design and costing of a planned Selectro™ demonstration plant.
Further work includes flotation testwork, continued Selectro™ testing, additional density testwork and the Phase 2 re assay program.
Approximately 80% of the company’s 1,000km² tenure package remains untested for scandium mineralisation.