St George Mining (ASX: SGQ) has announced excellent niobium and rare earth beneficiation results from initial flotation test work completed on mineralisation from the company’s 100%-owned Araxá niobium and rare earths project in Minas Gerais, Brazil.
The metallurgical test work results confirm the production of separate high-grade niobium and rare earth concentrates from near-surface mineralisation.
Niobium beneficiation
- Flotation beneficiation test work produced high-grade niobium concentrates with industry comparable recovery rates
- The test work sample comprised approximately five tonnes of near-surface saprolite material from the Araxá project considered representative of mineralisation that could be mined in a potential mining operation.
- Initial test work comprised open circuit flotation and achieved:
- 39.6% Nb₂O₅ concentrate grade at 54.3% flotation recovery; and
- 40.2% Nb₂O₅ concentrate grade at 46.0% flotation recovery
- Locked cycle and recycle flotation test work is now underway with the aim of optimising the beneficiation with increased recovery and grades
Rare earths beneficiation
- Rare earths concentrate stream with a grade of 15.7% TREO achieved in open circuit beneficiation test work
- The rare earths concentrate is comprised in the tailings from the niobium flotation, consistent with the flowsheet being developed for the dual processing of niobium and rare earths from the Araxá project
- Potential to upgrade rare earths during the niobium flotation process is confirmed, with further beneficiation through rare earths processing to be evaluated.
The next phase will comprise locked-cycle and recycle test work consistent with standard flotation flowsheet development practices. Mineralogical characterisation and beneficiation test work is ongoing at multiple international laboratories including in Brazil and at SGS Lakefield in Canada.
CIT-SENAI will conduct a one-month pilot plant study on niobium flotation during July 2026, with St George’s large-scale pilot plant scheduled to be operating by late Q4 2026.
Commenting on the test work results, St George executive chairman John Prineas said:
“Our Araxá project hosts world-class resources for each of niobium and rare earths – something which is unique among 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.
“The initial flotation results are very encouraging for our dual-commodity approach as they support the potential to produce commercial niobium and rare earths products from the Araxá mineralisation. This represents an important milestone for the project.
“High-grade niobium concentrate was produced in this early-stage flotation test work with recoveries and grades that are consistent with niobium mining operations with Araxá-style pyrochlore mineralisation.
“In addition, the open circuit beneficiation test work demonstrated the potential to upgrade rare earth concentrate in the niobium flotation tailings.
“The test work was completed on five tonnes of near-surface material likely to be the kind of ore mined in the initial years of a mining operation at Araxá, thereby providing a robust result for development study work.
“We are particularly pleased to have assembled a Brazilian and Australian technical team with extensive practical experience in both niobium and rare earths process development and operation, including previous experience at Araxá niobium operations along with Brazilian and international rare earths projects.
“Further work is now underway to optimise flotation performance, evaluate locked-cycle operation and assess downstream refining pathways.”
