Ark Mines’ 1.5-billion-tonne rare earths target gets a boost

Ark Mines has updated the exploration target for its Sandy Mitchell rare earths project in far north Queensland, cementing the project’s potential to become one of the largest “surface-expressed” rare earth projects globally.

In July, Sandy Mitchell’s exploration target was defined as 1.3–1.5 billion tonnes at 1250 to 1490 parts per million (ppm) monazite equivalent.

The target has now increased to 1.3–1.5 billion tonnes at 1286 to 1903 ppm monazite equivalent.

The increase builds off the recently updated mineral resource estimate, which now stands at 71.8 million tonnes at 1733 ppm monazite equivalent, using a lower cut-off grade of 700ppm monazite equivalent.

“The sheer scale of the Sandy Mitchell exploration target, up to 1.5 billion tonnes, delivers a clear statement that this project is emerging as one of the world’s largest surface-expressed terrestrial placer rare earth deposits,” Ark Mines executive director Ben Emery said.

“The finalised, quantitative evaluation of minerals using a scanning electron microscopy (QEM scan) resulted in valuable element deportments across the heavy mineral basket.”

The updated exploration target includes a basket of heavy minerals totalling 4.5–7.9 million tonnes, including monazite, xenotime, zircon, rutile and titanium.

Ark Mines said the update hasn’t made any changes to overall tonnage but does involve grade adjustment based on increased accuracy from the finalised QEM scan data from ALS, which was part of the metallurgical investigations Ark Mines commissioned through Mineral Technologies.

“We are excited to move forward with development for what is a very large deposit within a simple mineralised structure, which can be extracted with an extremely low environmental impact,” Emery said.

“The increase in MzEq (monazite equivalent) grades as part of this updated exploration target will be incorporated into a forthcoming scoping study for Sandy Mitchell, and we look forward to providing further updates on project development once the results of the scoping study are announced.”

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