Nickel and copper exploration company Desert Metals (ASX:DM1) reports it has achieved ‘exceptional’ rare earth element (REE) leach recoveries at the Innouendy Project in Western Australia.
The company says an additional 80 samples from Innouendy have been reanalysed using ALS Geochemistry’s Aqua Regia weak acid digest procedure. This procedure is used to determine the proportion of leachable REEs.
Desert states Aqua Regia is an ‘ideal’ medium on the release of elements adsorbed on clay particles though it will not dissolve ‘significant’ quantities of the silicate and alumino-silicate minerals of major refractory minerals when compared to the near total digestion of the Lithium Borate Fusion method (ME-MS81) or the Four Acid digest (ME-MS61).
These results demonstrate that the REEs at Innouendy are loosely bound and suggest ‘excellent’ recoveries are possible from a simple leach procedure.
Of note to the company are the ‘high-value’ magnetic REEs neodymium (Nd), praseodymium (Pr), dysprosium (Dy), samarium (Sm) and gadolinium (Gd), with average recoveries well over 80%.
The company recovered 86.3% of Nd2O3, 82.7% of Sm2O3, 82.4% of Gd2O3, 81.6% of Pr6O11, 76.1% of Dy2O3, 75.4% of Tb4O7, and 85.2% of Nd2O3+Pr6O11.
Desert also recovered 84.5% magnetic REEs (MREO), 83.2% critical REEs (CREO), 74.2% heavy REEs (HREO), 71.7% light REEs (LREO), 78.5% TREO-Ce (cerium), and 71.9% total REEs (TREO).
These results allow the company to proceed with confidence into a ‘significant’ program of ore characterisation and metallurgical testwork to further advance economic parameters for the REE project.
The Innouendy Project was first recognised by Aurora Minerals (ASX:ANX) as potentially prospective for nickel and copper sulphides by mapping weathered ultramafic outcrops in 2010. The company believes the project is prospective for economic nickel copper mineralisation due to conductive anomalies identified from 4 independent electromagnetic (EM) surveys conducted.
Desert Metals is an ASX-listed exploration company searching for intrusive nickel and copper on the northwest margin of the Yilgarn Craton in Western Australia. The company’s projects include the Irrida Hill Nickel, Innouendy Nickel, Dingo Pass, Opal Bore Gold, Hooper and Belele projects.
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