Chilwa Minerals Extends Niobium Mineralisation at Nakombe with 22m at 0.228% Nb2O5
Chilwa Minerals has confirmed significant niobium mineralisation in its southernmost drillhole at Nakombe, extending the known strike length to 270 metres and reinforcing the scale of its critical minerals project in Malawi.
- 22m at 0.228% Nb2O5 confirmed by pXRF in MPYDD015
- Mineralised strike length extended to 270 metres
- Niobium mineralisation remains open along strike and at depth
- ICP-MS assays pending to validate and potentially upgrade pXRF results
- Two diamond rigs active with Phase 2 drilling underway
Southernmost Drillhole Confirms Continuity of Niobium System
Chilwa Minerals Limited (ASX:CHW) has extended the footprint of its niobium discovery at the Nakombe syenite intrusion in Southern Malawi with drillhole MPYDD015 returning 22 metres at 0.228% Nb2O5 within a broader 161.5 metres zone averaging 0.165% Nb2O5, based on in-house portable XRF (pXRF) analysis. This southernmost hole effectively completes the 270-metre strike length of the mineralised system proven to date and confirms continuity with previous drillholes, including MPYDD009 drilled from the opposite end of the intrusion.
While pXRF results provide an indicative grade, Chilwa notes that this method tends to understate niobium grades by approximately 17-22% compared to external ICP-MS laboratory assays, which are pending. The company expects these forthcoming assays to confirm or improve upon the current results, which already demonstrate a substantial mineralised interval.
Drilling Highlights and Geological Interpretation
MPYDD015 intersected basement gneiss to 185 metres before entering the target alkaline syenite intrusion, where niobium grades increased with depth from 240 metres downhole. Notably, within the broader mineralised zone, the 22-metre interval from 349.5 metres downhole includes higher-grade sub-intervals such as 10 metres at 0.238% Nb2O5 and 2 metres at 0.275% Nb2O5.
Geological logging and pXRF data support the interpretation of a plug-to-pipe-like intrusive body plunging south or southwest. This structural model aligns with the increasing niobium grades observed deeper in the hole and is consistent with earlier drilling results at Nakombe.
Ongoing Drilling and Exploration Strategy
The company is advancing a two-rig diamond drilling program at Nakombe, with a third rig potentially on the way to accelerate exploration during the favourable Malawian drilling season. Phase 2 drilling is targeting the northern and eastern extensions of the system, areas that remain open along strike and at depth. Additional holes east of MPYDD014 are planned to test these extensions.
Chilwa is also progressing petrographic analysis, QEMSCAN mineralogy, and metallurgical test work to better understand the mineralisation and its processing characteristics. These efforts aim to underpin a maiden Exploration Target for the Nakombe niobium-REE-tantalum-gallium deposit.
Multi-Critical Minerals Potential in a Single Licence Area
Beyond niobium, Chilwa’s Lake Chilwa licence hosts a suite of critical minerals including rare earth elements (REE), tantalum, gallium, and heavy mineral sands (HMS). The company’s Mpyupyu Heavy Mineral Sands project and new Mpyupyu West HMS discovery complement the alkaline intrusive targets, creating a unique multi-commodity critical minerals portfolio within a single contiguous licence area.
Managing Director Cadell Buss emphasised the strategic importance of these results, stating that the MPYDD015 intercept "completes the picture across the full strike length we’ve tested to date" and that the company is "working towards definition of a maiden Exploration Target". The ongoing drilling and assay results will be pivotal in shaping the project’s development trajectory.
Bottom Line?
Chilwa Minerals’ latest drilling confirms a substantial and continuous niobium mineralised system at Nakombe, but investors should await pending ICP-MS assays and further drilling results to better define the scale and grade before drawing conclusions.
Questions in the middle?
- How will the pending ICP-MS assays compare to the current pXRF results in terms of grade and consistency?
- What size and grade will the maiden Exploration Target at Nakombe ultimately reflect once all data is integrated?
- How might metallurgical test work influence the economic viability of the niobium and co-product recovery?
