Mposa’s Rare Earth Inclusion Raises Stakes Amid Environmental Sensitivities
Chilwa Minerals has upgraded its Mposa deposit resource to 25.65 million tonnes, with 83% now classified as Measured, incorporating rare earth element monazite for the first time. This milestone enhances the project's geological confidence and economic potential.
- Mposa deposit resource increased to 25.65Mt with 83% Measured classification
- Inclusion of monazite, leucoxene, and garnet in mineral assemblage for first time
- Mposa Main NE sub-deposit shows higher grade at 5.61% total heavy minerals
- Heavy Mineral Concentrate increased to 1.07Mt reflecting improved modelling
- Scoping study underway targeting completion in Q1 2026
Resource Upgrade and Geological Confidence
Chilwa Minerals Limited (ASX, CHW) has announced a significant upgrade to its Mposa deposit mineral resource estimate (MRE) in Southern Malawi. The updated JORC 2012-compliant MRE now totals 25.65 million tonnes of Measured and Indicated resources, with an impressive 83% classified as Measured. This reflects the benefits of dense sonic drilling and refined geological modelling, which have substantially increased confidence in the deposit's extent and grade.
Rare Earth Elements Enter the Equation
For the first time, Chilwa has incorporated monazite; a rare earth element (REE) bearing mineral; into the resource model, alongside leucoxene and garnet. The inclusion of monazite is particularly noteworthy given the growing global demand for REEs in clean energy and technology sectors. QEMSCAN mineralogical analysis confirmed monazite's presence throughout the deposit, enabling quantification and laying the groundwork for evaluating its economic potential as a by-product alongside traditional mineral sands products such as ilmenite, rutile, and zircon.
High-Grade Core and Enhanced Mineral Concentrate
The Mposa Main NE sub-deposit stands out with a higher grade of 5.61% total heavy minerals (THM), representing 52% of the Measured Resources. This high-grade core offers Chilwa increased flexibility in project staging and development scheduling. Correspondingly, the contained Heavy Mineral Concentrate (HMC) has risen from 0.9 million tonnes to 1.07 million tonnes, reflecting improved domaining and block modelling parameters.
Metallurgical Progress and Project Outlook
Metallurgical test work on a 4.2-tonne sample from the deposit has successfully produced garnet and monazite concentrates, supporting the viability of these minerals as product streams. The company is progressing a scoping study, aiming for completion in the first quarter of 2026, which will incorporate these resource upgrades and metallurgical insights. Further resource updates are anticipated as drilling continues, particularly focusing on northern deposits in early 2026.
Environmental and Operational Considerations
Chilwa’s operations are mindful of the environmental sensitivity of the Lake Chilwa region, a Ramsar-designated wetland. The mineral sands deposits lie outside the wetland boundaries, and the company plans to employ dry mining methods with backfilling of tailings to minimize environmental impact. Low slime levels in the deposits further support efficient processing and rehabilitation strategies.
Bottom Line?
With rare earth elements now part of the equation and a high-grade core identified, Chilwa Minerals is poised to sharpen its development strategy as the scoping study unfolds.
Questions in the middle?
- How will the inclusion of monazite impact the project's economic feasibility and financing options?
- What are the timelines and expected outcomes for the upcoming scoping study and further resource updates?
- How will Chilwa manage environmental and permitting challenges given the proximity to a Ramsar wetland?
