Mount Ridley Mines (ASX:MRD) reports its Selectro process achieved 91.8% scandium recovery using half the reagent dose of previous tests.
The third Selectro leach test achieved the strongest rare earth element and scandium recoveries of the initial test work program. Notably, heavy rare earth element (HREE) recoveries averaged about 84%, with light rare earth element (LREE) recoveries averaging about 77%.
The improved recoveries were achieved using half the reagent applied in tests one and two. Selectro test three was conducted on unbeneficiated Grass Patch feed with no process optimisation applied.
Managing Director and CEO Allister Caird says the Selectro process results continue to deliver.
“Our wholly owned and patent-pending Selectro process results continue to impress, with scandium recovery increasing to 91.8% and REE recoveries improving across the board, HREE averaging 84% and up to 86%,” Caird adds.
“These improvements were achieved while halving the reagent dose used in the previously reported Selectro tests, indicating the potential for further cost benefits.”
The company has not yet established the lower limit of reagent concentration, and further recovery improvements may be achievable at an even lower dose. Gallium recovery was about 41.5%, down from 55.8% in test two at the reduced reagent dose.
The improvement reflects molecular tuning of the Selectro leaching chemistry, whereby the composition of the leaching molecule can be adjusted to optimise recovery of targeted metals.
CTO Chris Larder says the latest test examined whether metal recovery could be improved through molecular tuning.
“The results make it clear that tuning delivered material improvement, with scandium recovery increasing from 80% to 91.8% while the reagent dose was halved,” Larder notes.
“Selectro also operates at low temperature and ambient pressure and is designed to fully recycle its reagents, pointing to a potentially attractive operating cost profile compared with alternative extraction methods.”
Flotation test work on Grass Patch material is underway ahead of the bulk sample program. The company will incorporate Selectro test three results into updated process economics and scoping assumptions.
Mount Ridley Mines is an Australian critical minerals explorer focused on heavy rare earth elements, gallium, and scandium across its Mount Ridley and Weld Range projects in Western Australia.
Write to JC Villarba at Mining.com.au
Images: Mount Ridley Mines
