Resource Upgrade Looms as Chilwa Reports Strong Mineral Sands Intersections

Strong Assay Results Reinforce Mpyupyu Dune Potential

Chilwa Minerals Limited (ASX – CHW) has announced a third batch of assay results from its ongoing sonic drilling program at the Mpyupyu Dune deposit, part of its broader Critical Minerals Project in southern Malawi. The 95 drill holes, totaling 692 meters, have returned impressive Total Heavy Mineral (THM) grades, with some intervals exceeding 40%, confirming the high-grade nature of the deposit.

These results build on previous drilling campaigns and reinforce the geological model that mineralisation is concentrated in two sub-parallel lobate strandlines known as the Mpyupyu Dunes. The Dunes form a higher-grade portion of the larger Mpyupyu deposit, which currently holds an Inferred Mineral Resource Estimate (MRE) of 19.9 million tonnes at 4.2% THM. Within this, the dune area alone accounts for 3.5 million tonnes at 7.1% THM, significantly above the average grade of the flats portion.

Operational Advances and Resource Upgrades

Chilwa has highlighted the benefits of its new primary assay laboratory, Light Deep Earth (LDE) in Pretoria, South Africa, which has accelerated turnaround times for assay results. This improvement is critical as the company prepares to update its mineral resource estimates not only for Mpyupyu but also for other key deposits such as Mposa and Bimbi. The Mposa resource update is expected imminently, with Bimbi and Mpyupyu upgrades to follow swiftly.

Drilling at Mpyupyu Dunes has now covered over 3 kilometers of strike with 359 holes completed for a total of 2,716 meters. Meanwhile, drilling at the Mpyupyu Flats area has concluded with 353 holes and samples are being processed for assay. These comprehensive drilling programs are designed to provide a robust geological and grade continuity framework to support future mining studies and scoping studies planned for later in 2025.

Broader Project Context and Rare Earth Exploration

The Mpyupyu deposit is one of ten identified heavy mineral sands deposits within the Chilwa Critical Minerals Project, which is strategically located around Lake Chilwa. The project benefits from a rich geological setting formed by palaeostrandline deposits, with mineralisation influenced by historic lake level fluctuations and sediment supply from surrounding basement rocks.

In addition to heavy mineral sands, Chilwa is advancing exploration for rare earth elements (REE) across 47 carbonatite targets in the region. Soil sampling has been completed on the majority of these targets, with positive pathfinder results reported earlier this year. Drilling at the Mposa target is ongoing, with core samples from the first hole currently being analysed at LDE. Rare earth assay results are anticipated in the coming weeks, potentially adding a valuable dimension to the project’s critical minerals portfolio.

Looking Ahead

Chilwa’s methodical approach to drilling, sampling, and assay quality control, combined with the use of industry-standard sonic drilling techniques, underpins confidence in the forthcoming resource updates. The company’s engagement of TZ Minerals International to manage metallurgical testwork and flowsheet studies further signals its commitment to advancing the project towards economic evaluation.

With multiple resource upgrades and a scoping study on the horizon, Chilwa Minerals is positioning itself to unlock significant value from its Malawi mineral sands and rare earth assets. Investors will be watching closely as assay results and study outcomes unfold in the coming months.