New petrology results based on drill samples from Red Mountain Mining’s (ASX: RMX) Mt Mansbridge project in Western Australia has confirmed the presence of key rare earth elements (REE) xenotime and florencite.
The explorer said the minerals are found within quartz veining and the associated wall rock alteration at the East Kimberley project.
Three samples taken from a recently announced mineralised zone from a drill hole at the Solo prospect were sent to Diamantina Laboratories in Perth and reviewed using optical scanning electron microscope (SEM) techniques.
Xenotime is a REE phosphate material mainly composed of yttrium orthophosphate. The REEs dysprosium, erbium, terbium and ytterbium are the expressive secondary components of xenotime.
Red Mountain said the significance of xenotime is the mix of REE in the mineral. The lanthanide content runs about two-thirds yttrium and largely a source of heavy lanthanide metals dysprosium, ytterbium, erbium and gadolinium.
Based on the drill samples taken from the Solo prospect, the average ratio of heavy rare earth oxide (HREO) to total rare earth oxide (TREO) is 66.62%.
According to Red Mountain, petrological studies have confirmed the presence of heavy REE (HREE) xenotime, which is dominated by yttrium at 43.15% followed by dysprosium at 5.65% and 0.97% terbium.
Red Mountain non-executive chairman Troy Flannery said the petrological confirmation of xenotime marks a “significant technical step” in HREE exploration at Mt Mansbridge.
“With a similar mineralisation to the Browns Range project along with its close proximity to Northern Minerals’ (ASX: NTU) processing facility makes the Mt Mansbridge project highly prospective,” he added.
Importance for green energy transition
HREEs are considered critical for energy transformation but are rarer than light REEs and subsequently, attract higher prices.
Permanent magnets are critical components for electric motors in electric vehicles and power generators widely used in wind turbines that contain HREEs to provide greater efficiency and range.
For example, dysprosium is used to improve a magnet’s resistance to demagnetisation and allows for magnets to retain their magnetic properties, even at high temperatures such as is the case in electric vehicle use.
Dysprosium is also important in wind turbines, nuclear reactors and other military applications, making it a highly strategic mineral. Together with neodymium, dysprosium is listed as a critical material by the US Department o Energy and other international institutes due to its high supply risk.
Other high value HREEs include terbium, which is often used as a substitute for dysprosium, and lutetium, the rarest and most valuable REE.
According to Red Mountain, all of these valuable REEs contribute economically to typical xenotime deposits.
2022 drilling plans
Red Mountain said it is planning on resuming its drilling program at Mt Mansbridge at the end of the Kimberley wet season in early 2022.
Substantial access tracks have now been established at the project and heritage clearance has been achieved.
In today’s announcement, the company said the completion of reverse circulation drilling is expected in the second quarter of the calendar year.