St George Mining Advances Pilot Plant Test Work at Araxá Project

Pilot Plant Study Targets Dual Commodity Recovery

St George Mining (ASX:SGQ) has commenced a pilot plant beneficiation program at the Araxá Project in Minas Gerais, Brazil, aiming to advance the processing of its world-class niobium and rare earth mineralisation. The study, conducted at the CIT-SENAI facility in Belo Horizonte, utilises approximately 9 tonnes of near-surface saprolite material representative of early mining phases.

The pilot plant incorporates grinding, magnetic separation, and flotation stages designed to produce a high-grade niobium concentrate alongside a rare earth enriched tailings stream. Locked cycle flotation tests with recycle streams are included to optimise recovery and concentrate grades, building on promising initial flotation results that delivered niobium grades comparable to established operations.

Downstream Processing Focused on Ferroniobium and Rare Earth Products

The niobium concentrate from the pilot plant will undergo further processing trials targeting ferroniobium containing around 65% niobium oxide. The approach mirrors industry-standard pyrometallurgical methods, including electric arc furnace refining to remove impurities and aluminothermic reduction to produce ferroniobium metal, akin to the process used by CBMM, the world’s largest niobium producer adjacent to Araxá.

Meanwhile, the rare earth enriched flotation tailings will be subjected to hydrometallurgical test work aiming to produce intermediate products such as mixed rare earth carbonate (MREC) or rare earth oxalate. Historical pilot plant work on Araxá mineralisation has previously demonstrated high purity rare earth oxalate with strong total rare earth oxide recoveries, underscoring the deposit’s amenability to rare earth processing.

Building a Dedicated Technological Centre in Araxá

Complementing the current pilot plant study, St George is constructing its own large-scale pilot plant at the CEFET-MG campus in Araxá. Designed for a throughput of up to 300 kilograms per hour, this facility will handle niobium flotation and rare earth product generation, including concentrates and oxides. Construction has started with environmental and building permits secured, targeting commissioning in January 2027.

St George’s in-house plant engineers, with extensive experience from CBMM and other regional operations, are overseeing the project alongside feasibility adviser Worley. The new technological centre aims to underpin the company’s processing development and support feasibility studies for a potential mining operation.

Araxá Project: A Growing Rare Earths and Niobium Giant

The Araxá Project recently underwent a major resource upgrade, establishing it as the largest and highest-grade hard-rock rare earths resource in South America. The total mineral resource estimate now stands at 111.2 million tonnes at 3.57% total rare earth oxides (TREO) and 0.57% niobium pentoxide (Nb₂O₅), with measured and indicated resources comprising 75.2 million tonnes at higher grades.

Located adjacent to CBMM’s established niobium operations, Araxá benefits from existing infrastructure and a skilled workforce. St George has also initiated environmental permitting processes with Minas Gerais authorities, following government support for expedited approvals. These steps mark important milestones as the company progresses towards development.

Experienced technical leadership is driving metallurgical studies, including former CBMM personnel and independent experts, ensuring robust test work and mineralogical characterisation across multiple international laboratories. Results from the current pilot plant program are expected in the final quarter of 2026, providing critical data to refine the flotation flowsheet and downstream processing strategies.