American Rare Earths Ltd (ASX:ARR) is a step closer to commercialisation of a major US rare earths project with the receipt of results of initial mineralogy test work conducted on core material from the Halleck Creek Rare Earths project in Albany County, Wyoming.
The results provide further confidence in the potential for Halleck Creek to be a key strategic project within the USA, helping to onshore supply of critical rare earths.
The mineralogy test results show that the rare earth host mineral – Allanite – at Halleck Creek can be easily recovered using a simple separation technology, and contains roughly 90% of the total rare earths present.
The simplicity with which Allanite can be liberated allows for higher recovery rates and the ability to upgrade rare earth elements at lower costs.
Game-changer
This development increases the company’s confidence that a metallurgical process for production can be developed – a first plank in its commercialisation strategy.
This could have significant economic benefits for the Halleck Creek Project.
The test works were conducted under the guidance of Wood Australia, mineralogical characterisation testing was performed by SGS Canada, and Nagrom completed the hydrostatic analysis.
ARR managing director Chris Gibbs said: “These are highly encouraging results for Halleck Creek and we’re particularly excited about the straightforward mineralogy of this deposit.
“The Halleck Creek Project is shaping up to being a world class tier one asset. The sheer size, scale and nature of the deposit lends itself to a low-cost open cut mining operation, and not too complex metallurgy.
“The mineralogy test work determined that rare earths elements (REE)-rich Allanite is the primary REE-bearing mineral at the project.”
Reduced capital costs
The average grain size of the observed Allanite was 232 microns, indicating a coarse grain structure. This constitutes approximately 87.5% of all Allanite in the sample material with minimal gangue (waste) minerals.
The coarse grain size indicates that the Allanite will respond well to standard Wet High-Intensity Magnetic Separation (WHIMS), with potentially high recoveries and upgrading of rare earth elements, including neodymium and praseodymium.
This suggests that considerable reductions in operating and capital costs for production facilities could be achieved due to the simplicity of initial ore recovery and reductions in grinding costs.
What's next?
The program of metallurgical test work continues as the company seeks to firm up the processing flow sheet.
Test work on the comminution circuit and magnetic separation is underway at Nagrom Laboratories in Perth, Western Australia.
ARR will then transition to flotation testing of WHIMS magnetics at Auralia Metallurgy, to assess the potential for further upgrading.
Auralia will soon start preliminary work on a sample of fresh ore to screen reagents such as collectors and depressants ahead of the work on WHIMS magnetics.