Mposa Metallurgical Results Boost Chilwa’s Critical Minerals Ambitions Amid Scoping Study

Metallurgical Breakthrough at Mposa

Chilwa Minerals Limited (ASX – CHW) has unveiled further positive metallurgical testwork results from its flagship Mposa Deposit, a key component of the Lake Chilwa Critical Minerals Project. The recent work, based on a 2.7 tonne composite sample derived from drill core, confirms the ability to produce a sulfate grade ilmenite concentrate boasting 51.1% titanium dioxide (TiO2) content. This milestone is significant as it demonstrates the viability of standard mineral sands processing techniques to generate a commercially attractive ilmenite product.

Alongside ilmenite, the testwork revealed high recoveries of zircon (zirconium oxide, ZrO2), garnet (almandine), and rare earth minerals, notably monazite. These by-products could diversify revenue streams and enhance the project's economic robustness. The presence of rare earth elements further underscores the strategic importance of the deposit within the critical minerals sector.

Comprehensive Testing and Flowsheet Development

The metallurgical program, conducted by LightDeepEarth (Pty) Ltd, involved detailed physical fractionation, magnetic separation, and flotation trials. The heavy mineral concentrate (HMC) achieved an impressive 89% total heavy minerals grade, with 91% recovery of both TiO2 and ZrO2 into the gravity upgrade circuit. Notably, ilmenite recovery reached 93% relative to the HMC, while zircon recovery into non-magnetic streams was 96%, highlighting efficient separation processes.

Work is ongoing to refine the processing of non-magnetic fractions to optimize the quality and recovery of zircon, rutile, garnet, and rare earth concentrates. The results to date have informed the development of a preliminary flowsheet incorporating screening, desliming, gravity upgrading, and magnetic separation. This flowsheet will be finalized as part of the Scoping Study, which TZ Minerals International is undertaking with completion expected in the fourth quarter of 2025.

Resource Expansion and Strategic Outlook

Complementing the metallurgical advances, Chilwa continues resource drilling at Mposa to upgrade the Mineral Resource Estimate (MRE) with a focus on Measured and Indicated categories. The updated MRE, announced in June 2025, reports 4.44 million tonnes of contained total heavy minerals at a 1.0% cut-off, supporting the project's scale and potential.

Managing Director Cadell Buss emphasized the project's multi-commodity nature and critical minerals credentials, noting the rare earth mineral presence strengthens confidence in the underlying carbonatite system. The company is also evaluating logistics advantages, including proximity to a rail corridor linking to the Nacala sea port in Mozambique, which could reduce transport costs.

Looking Ahead

Chilwa's methodical approach to flowsheet development and resource definition positions the company well to advance the Lake Chilwa project towards feasibility. The integration of multiple valuable mineral products enhances the project's appeal amid growing demand for critical minerals globally. Investors and analysts will be watching closely as the Scoping Study progresses and further metallurgical optimizations are reported.