• Infill drilling has proved the continuity of ionic-clay REEs between initial holes
  • Assays have returned significant REE results with high levels of magnet REEs
  • More infill and step-out drilling to come


Tim Goyder-chaired DevEx has received a strong hint about the potential scale and quality of its Kennedy ionic clay-hosted rare earths discovery in Queensland.

A new ‘infill’ drilling program confirmed significant rare earths in surface clays between previous broad spaced holes, with many hitting high value magnet rare earth elements (REEs).

It follows on from DevEx Resources (ASX:DEV) previous 11 hole, broad-spaced drilling (~1km hole spacing) each of which hit rare earths from surface in the first 2m to 4m.

Best intervals from the new program ranged between 2-4m at 728ppm-1734ppm TREO from surface, which include important and high-value rare earth elements such as praseodymium (Pr), neodymium (Nd), dysprosium (Dy) and terbium (Tb).

Results topped out at 378ppm neodymium, 101ppm praseodymium, 10.4ppm terbium and 62ppm dysprosium in hole KRAB016.

These four REEs are essential in the manufacture of permanent rare earth magnets used in electric vehicles and numerous other renewable energy applications.

To confirm the continuity of mineralisation between these initial holes is strong indicator that there is some real scale present at Kennedy, particularly when one considers that the drilled area is but part of a broader 30km by 20km prospective area.

Scale is important for clay-hosted REE projects as they have lower grades then their hard rock counterparts but make up for it by being easier to mine – thanks to shallow, easy-dig mineralisation, and in the case of ionic adsorption type mineralisation, greater ease of processing as well.

Notable examples of ASX companies with large-scale REE project include Australian Rare Earths (ASX:AR3) with its Koppamurra project in South Australia and Meteoric Resources (ASX:MEI) Caldeira in Brazil.


A true ionic deposit

To top it off, metallurgical testing has already provided early evidence that Kennedy is an ionic-clay discovery with samples taken from the initial holes demonstrating rapid recoveries by desorption of REE in the first 30 minutes using an ammonium sulfate (AMSUL) solution in weak acidic conditions (pH4).

This achieved recoveries of 38% praseodymium, 40% neodymium, 29% dysprosium and 31% terbium, which increased to 49% praseodymium, 51% neodymium, 44% dysprosium and 47% terbium when left for 24 hours.

This is important for potential project economics. The less acid a company must use to leach out the REEs, the cheaper and easier it will be to mine and process.

DevEx has since engaged the Australian Nuclear Science and Technology Organisation (ANSTO) for further leach tests.


Ionic clays in demand

That the company already has some early indications that Kennedy is indeed an ionic-clay find is significant as such deposits are much sought after.

Largely found in China these projects are known for their ease of mining, processing and hosting higher proportion of magnet REEs and heavy REEs.

Such ionic-clay deposits are generally distinguished by having an ionic phase that is easily, quickly and cheaply desorbed with a salt solution at pH4, something which DevEx has already achieved at Kennedy.


Further activity

DevEx plans to carry out further infill aircore drilling on the centre drill traverses during August and September.

This will be carried out alongside a larger step-out program designed to test the broader extent of mineralisation at Kennedy.




This article was developed in collaboration with DevEx Resources, 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.