St George Mining has kicked a major goal at its world-class Araxá niobium and rare earths project in Brazil, with initial metallurgical testwork successfully producing two separate high-grade concentrates from a single ore stream.
The Perth-based explorer says early-stage flotation work on a five-tonne bulk sample of near-surface saprolite ore delivered a niobium concentrate grading an impressive 39.6 per cent niobium pentoxide with a solid 54.3 per cent recovery.
Notably, the company then produced a separate rare earths concentrate grading 15.7 per cent total rare earth oxides (TREO) from the tailings of the niobium flotation circuit.
The results are a significant de-risking event for the project, confirming the viability of a dual-commodity flowsheet which could see St George producing two distinct and valuable critical mineral products from a single mining operation.
The initial testwork was conducted using an open-circuit flotation process, which is typically the first step in metallurgical evaluation. The company says the niobium concentrate grades and recoveries are consistent with existing commercial niobium operations in the Araxá region – a massive tick for a project at this stage of development.
The rare earths results are arguably just as significant. By producing a 15.7 per cent TREO concentrate from the niobium tailings, St George has demonstrated a potential 1.6 times upgrade from the feed material and confirmed a pathway to a second revenue stream.
The ability to successfully separate and upgrade both commodities from a single ore source is a clever piece of work that could have a profound impact on the project’s future economics.
The results build on the massive 70.91-million-tonne resource St George defined at Araxá earlier this year, grading a notable 4.06 per cent TREO and 0.62 per cent niobium pentoxide. The deposit begins at surface, is considered “free-digging” and sits in the heart of Brazil’s premier niobium district, right next door to the world’s largest rare earths producer, CBMM.
St George Mining executive chairman John Prineas said: “Our Araxá project hosts world-class resources for each of niobium and rare earths – something which is unique amongst our critical metals peers. Our aim is to capture the full value of this mineralisation by producing commercial products of both niobium and rare earths in a potential mine development at Araxá.”
With the initial open-circuit tests proving successful, St George is now accelerating its metallurgical program. The company has already kicked off locked-cycle flotation testwork to optimise the process and improve recoveries and grades for both commodities.
Locked-cycle is typically a repetitive batch test used in mineral processing to simulate a continuous commercial circuit on a laboratory scale.
Further work will also include detailed mineralogical studies at international laboratories in Brazil and at SGS Lakefield in Canada.
In a sign of the pace at which the company is moving, a one-month study on niobium flotation is scheduled for next month, with St George’s own large-scale pilot plant slated to be up and running by the end of the year.
It has been a rapid-fire run for St George since it acquired the Araxá project in early 2025. In just over a year, it has established itself as a world-class resource and is now well on its way to cracking the metallurgical code.
Proving you can get two valuable products for the price of one is a compelling economic argument. With both niobium and rare earths now showing a clear processing pathway from a single ore body, St George might just be lining up for a feast.
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By Doug Bright
