The latest results from metallurgical test work at the Cowalinya Project in WA’s Norseman-Esperance region provide a solid technical platform for the company’s development plans.
Initial work by Perth-based Strategic Metallurgy has now wrapped up on 13 four and five metre composite samples of rare earth-bearing saprolite from 10 drill holes across the Cowalinya South and North deposits.
Taken together, the Cowalinya South and North deposits are the foundation of Heavy Rare Earths (ASX:HRE) maiden Inferred Resource of 28 million tonnes at 625 ppm TREO (total rare earth oxide).
Work by Strategic has shown a number of things – that 78.5% of the rare earths are confined to the target size fraction of -25µm, the target size fraction comprises 37.2% of the bulk saprolite feed mass, and the rare earth grade of the target size fraction is 116% higher than the bulk saprolite feed grade.
The best results achieved in the sizing work were 90.1%, 20.8% and a massive 299% respectively, with a maximum grade of 3674 ppm TREO observed in the target size fraction.
Most importantly, there is also a close correspondence between the distribution of total rare earths and the valuable magnet rare earths (Pr-Nd-Tb-Dy) in the -25µm size fraction.
Moving towards leach phase of target size fraction test work
“Our metallurgical program now moves to the next phase of test work by Strategic which is aimed at establishing a suitable leach regime for Cowalinya mineralisation,” HRE executive director Richard Brescianini says.
“This phase, which examines leach performance, solution composition, reagent consumption, metal recovery and impurity deportment, has commenced on -25µm target material isolated during the particle size analysis.
“Preliminary work by HRE showed that high proportions (89% on a weighted average) of the magnet rare earths can be brought into solution using weak hydrochloric acid,” he explains.
“The key outcomes from this next phase of work will be communicated to the ASX as material results come to hand.”
This article was developed in collaboration with Heavy Rare Earths, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.