Mount Ridley Mines (ASX:MRD) may have just added another dimension to its critical minerals story.
First metallurgical results from the company’s proprietary Selectro™ Process have delivered strong recoveries across heavy rare earths, scandium and gallium, all through a single leach process.
Against conventional hydrochloric acid testing, the difference was significant.
The numbers stand out
Selectro™ achieved 77–83% recoveries across key heavy rare earths, including dysprosium, terbium and yttrium.
Light rare earth recoveries reached 70–77%, including the magnet metals neodymium and praseodymium.
But scandium and gallium arguably delivered the bigger surprise.
Scandium recovery reached 80%, compared with just 27.6% from the conventional HCl baseline.
Gallium averaged around 56% recovery.
The HCl test recovered zero.
Importantly, these are initial laboratory results from unbeneficiated material, before systematic reagent and process optimisation.
Figure 1: Heavy REE Recovery for Selectro tests 1 and 2 against baseline HCl performed on the same composite sample.
Three minerals, one process
That is where Selectro™ becomes particularly interesting.
Rather than looking at separate processing routes, Mount Ridley is developing a process capable of extracting rare earths, scandium and gallium from the same feed stream.
The company has also designed Selectro™ as a closed-loop system using lower-cost reagents than conventional HCl processing, with reagent recycling intended to reduce both operating costs and environmental impact.
Managing Director Allister Caird said the results support the company’s view that Grass Patch is a genuinely polymetallic system capable of producing multiple critical minerals from one process.
Grass Patch brings the scale
There is already plenty of material for Mount Ridley to work with.
Grass Patch hosts an Inferred scandium resource of 367.98Mt @ 57.3ppm Sc, which the company describes as one of the largest globally.
Its Inferred gallium resource stands at 838.7Mt @ 29.3ppm Ga.
Add heavy and light rare earths into the equation and the opportunity becomes less about extracting one commodity and more about determining whether several valuable products can ultimately be recovered economically from the same system.
That could materially change how Grass Patch is evaluated.
Figure 2: Location of the Grass Patch samples used to prepare the Selectro™ & TIMA composite.
Bigger than Grass Patch?
There is another angle investors should watch.
Mount Ridley believes Selectro™ could potentially work across other deposit types, including lateritic and sedimentary-hosted systems.
The company is already assessing third-party licensing opportunities globally.
That remains early-stage, but successful validation on external feedstock could turn Selectro™ from an internal processing solution into a standalone technology opportunity.
What’s next
Now Selectro™ needs to prove it can scale.
Mount Ridley will move into bulk-sample testing, including trials using beneficiated feed following flotation. Further work will target process optimisation, reagent recycling and downstream product development.
The company also plans to test Selectro™ on third-party material.
The first-pass numbers are strong. The next question is whether Mount Ridley can repeat, and potentially improve, those recoveries as testing moves closer to commercial conditions.
