Rare earth elements (REEs) are considered critical minerals in all major countries, with long term forecasts predicting significant demand growth across the globe.
The importance of rare earths in new domestic and defence technologies has seen governments around the world place major importance on REE exploration, as they seek new supplies apart from those provided by leading rare earths producer, China.
lready a significant producer in the global market, Australia is positioned to become an REE powerhouse with a recent wave of ionic adsorption clay deposit discoveries across the nation.
While the exploration for REE producing ionic adsorption clay deposits is relatively new in Australia, it is not in China.
Global resources of heavy REEs are dominantly sourced from Chinese regolith-hosted ion-adsorption deposits.
Now, with several new clay deposits uncovered in Australia, a significant REE gold rush is happening across the country, with new exploration campaigns announced on a weekly basis.
The wide-spread nature of the REE producing ionic adsorption clay deposits is highlighted by several recent announcements.
ABx hits key milestone in Tasmania
In early May, ABx Group (ASX: ABX) revealed it had exceeded the 20Mt resource milestone in its updated mineral resource estimate (MRE) for the REE deposit at the Deep Leads-Rubble Mound project in northern Tasmania.
“This substantial upgrade of the mineral resource arises from 30 new holes, redrilling old bauxite holes that did not reach the REE horizon and more assays from incompletely assayed thick REE zones,” managing director and CEO, Mark Cooksey, said.
“As predicted, the thickness of the mineralized horizon has increased by 10% to 7.7m, and the grade has increased by 15%. The grades and thickness of the more closely drilled indicated resources category have increased significantly.”
“ABx has assessed available production technologies and recently commenced field and lab testing of production alternatives, focusing on production at the all-important pH4.”
“Only true ionic adsorption clay REE deposits, like ABx’s, can deliver high recoveries using benign, low-cost processing. Our work with Australian Nuclear Science and Technology Organisation (ANSTO) confirmed our mineralization as ionic adsorption clay.”
“The enriched levels of the high-value, permanent magnet rare earths used in advanced technologies is an exceptional feature of this deposit, which could be amenable to the very low-cost production methods that are being tested by ABx and specialist consultants.”
“Not all clays are created equal and, while REEs in clays are an emerging exploration target, very few deposits globally are confirmed as ionic adsorption clay REE mineralization that are amenable to low-cost benign production methods.”
Australia is positioned to become an REE powerhouse with a recent wave of ionic adsorption clay deposit discoveries across the nation
Krakatoa erupts with NSW discovery
On the same day, Krakatoa Resources Limited (ASX: KTA) confirmed it had discovered a new clay hosted REE province at the Rand project in NSW, Australia.
Firstpass air-core (AC) drilling on new, high-priority REE targets at the project in the Riverina region has defined anomalous REEs hosted in clay-weathered granites at shallow depths.
Drilling has led to the company making the clay-hosted REE discovery at Rand, supported by numerous significant intersections from clay-weathered saprolites developed on the Ryan and Jindera Granites.
“Our project continues to deliver significant outcomes for the company and these assay results from first pass, wide-spaced AC drilling, are highly encouraging and proved that these selective granite types have the potential to host shallow clay REE deposits.” CEO Mark Major said.
The company is sending certain AC samples to an accredited laboratory to undertake simple leach test work to determine the viability for extraction of key REEs such as neodymium, praseodymium, dysprosium, and terbium. Further interpretive work will be completed on the AC drilling programme results before further shallow drilling is planned.
Australia is positioned to become an REE powerhouse with a recent wave of ionic adsorption clay deposit discoveries across the nation
Western Australia success
Codrus Minerals (ASX: CDR) also announced it had intersected a significant zone of high-grade clay hosted REE mineralization in its maiden reverse circulation (RC) drill-hole, completed as part of its maiden drill programme at the recently acquired Karloning REE-Niobium project in Western Australia.
Initial assays from the top 40m of the first hole completed at the project returned a high-grade intercept of 12m grading 2,680ppm TREYO, including 4.0m grading 4,764ppm TREYO from hole KLRC001.
The recently completed drilling programme was aimed at confirming the project’s credentials as an exciting growth and diversification opportunity for Codrus in the rare earths sector, with all samples submitted for assay. Results for the first hole were rushed for analysis based on visual observations.
Managing director, Shannan Bamforth, said the project offers compelling exploration potential for the high value REEs used in the manufacture of high strength permanent magnets – namely praseodymium, neodymium, terbium, and dysprosium.
He stated these elements are in high demand because of the explosive growth in industries that rely on permanent rare earth magnets, such as electric vehicles, wind turbines, and other renewable energy applications.
“This is a very exciting result from our first ever drill hole at Karloning, confirming the presence of shallow clay hosted rare earths mineralization, in addition to the hard rock hosted REE mineralization that the project was originally acquired for.”
“This provides Codrus with the opportunity to pursue rare earths discoveries within two separate geological units – both the near-surface clay horizon and the pegmatites,” added Bamforth.
“This first round of drilling at Karloning is now complete, with assays from the lower portion of KLRC001 and the other 12 drill holes eagerly awaited. Results are expected to significantly enhance our understanding of the structure and distribution of rare earths and niobium mineralization at Karloning, which offers an outstanding opportunity for Codrus to diversify into the critical metals space.”
Desert Metals on target
Elsewhere in the state, Desert Metals (ASX: DM1) is undertaking a major programme of works at its Innouendy REE discovery.
The company has spent the initial portion of 2023 studying assay results for outstanding samples from its 313-hole AC drilling programme at the discovery. During Q1 2023, the company
interpreted these results to develop an understanding of both the key geological controls to mineralization and the likely volume of mineralization present. The aim of this work is both to guide future exploration drilling and to produce a JORC compliant resource.
Desert Metals management recently noted that all indications show that the REE mineralization at Innouendy is vast.
Work in the future will focus on identifying and developing the highest, most easily recoverable grades into volumes that might become a resource. Most of the drilling to date has been within the weathered clay layer, but the paleochannels identified from airborne EM data remain largely untested. It remains the company’s hypothesis that these channels represent the most significant untested part of the Innouendy REE discovery and offer potential for both high-grade and volume, as well as easily recoverable mineralization.
