• Metallurgical testing at Sandy Mitchell commences this week
  • Historical panned concentrate assays show up to 18.4% TREO – with 25% of that being high value NdPr
  • The project’s placer deposits could be easier to mine and process


Metallurgical test work is under way at Ark Mines’ unique Sandy Mitchell project in northern QLD, which could be brought into production much quicker and cost-effectively than a hard rock or ionic clay REE deposit.

A concept study for mineral sands flowsheet development – including REE mineral beneficiation evaluation – will provide detailed ore characterisation to define its composition, as well as extraction and processing techniques.


Significant, low capex upside

Sandy Mitchell is unique compared to other REE deposits, as the materials are hosted in fine sands known as terrestrial placer deposits, which are amenable to simple panning into a concentrate.

This means a potentially fast-start up beneficiation gravity processing model, Ark Mines (ASX:AHK) says, with significantly lower processing costs than hard rock and ionic clay-hosted REE projects.

Acquired in March this year for $200,000, Sandy Mitchell has already had significant exploration work done, showing high grades panned concentrates of up to 18.4% total rare earth oxides (TREO), with neodymium and praseodymium (NdPr) making up 25% of the TREO content.

NdPr is extremely valuable for its use in a range of applications including permanent magnets in EVs and renewable energy products – yet China, which is responsible for ~90% of NdPr production – is predicted to slow down its exports of the elements to feed its domestic market.

Hence, explorers elsewhere, such as Ark Mines, are looking to prove up REE projects with high concentrates of NdPr to feed growing demand.

Ark recently completed 144 drill holes for 1,505m as part of a Phase 1 AC drill campaign which returned REE and heavy mineral mineralisation out of every hole.


Next steps

Ark Mines exec director Ben Emery says test work will give the explorer a greater understanding of the project and is likely to take six weeks.

“Whilst the sands from the project can be upgraded to a concentrate by gravity means, conducting metallurgical testing at Sandy Mitchell is imperative for us to understand the concentrate product, the grades, recoveries, style of mineralisation, and the process techniques to extract valuable REEs, as well as heavy minerals such as zircon and titania from the material,” Emery says.

“The project is well-endowed with REEs and heavy minerals and our objective is to produce and sell both.

“In the interim, we anticipate releasing assays from the first drill program very shortly and this will help us define next steps for an expanded drill program and other project development activities.

“Being a placer deposit gives us a number of unique advantages in bringing the project into production much more rapidly and cost-effectively than a hard rock or ionic clay deposit.”

Ark says Sandy Mitchell is also likely to almost double in area from the current 147 km2 of tenements held, as contiguous sub-blocks of over 138km2 are currently under application.

In addition to Sandy Mitchell, Ark is working on the Mount Jess copper and iron project and the advanced 1.34Mt nickel, 602,000t cobalt and 191,500t copper Gunnawarra project.



This article was developed in collaboration with Ark Mines, 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.