Chilwa Minerals (ASX: CHW) has confirmed the discovery of niobium mineralisation at the Mpyupyu target within its Lake Chilwa critical minerals project in southern Malawi.
The announcement follows the receipt of further ICP-MS (inductively-coupled plasma mass spectrometry) assays from two diamond holes completed at the south end of the target and complements significant total rare earth oxide (TREO) mineralisation reported from an initial hole late last year.
The identification of niobium has added a separate dimension to Chilwa’s project, alongside defined heavy mineral sands resources and the potential rare earth element and ionic clay rare earth element portfolio.
It is seen as reinforcing the Lake Chilwa basin as a globally-significant, multi-commodity critical minerals system.
Niobium-Enriched Intercepts
The nature and consistency of niobium grades at Mpyupyu confirmed the presence of a niobium-enriched intrusive phase over 120 metres (downhole thickness) in extent.
Best intercepts were 0.31% niobium pentoxide (1,661 parts per million TREO, 174ppm tantalum and 55ppm gallium) over 126.1m from 125m, and 0.38% niobium pentoxide (1,654ppm TREO, 225ppm tantalum and 61ppm gallium) over 62m from 138m including 0.45% over 10m (2,365ppm TREO, 317ppm tantalum and 64ppm gallium) from 190m.
TREO remain present and elevated throughout the drillholes but is considered to be subordinate to the niobium identified in a specific alkaline syenite intrusive phase in the south of the Mpyupyu system.
Chilwa reported a best recovered grade of 2,670ppm TREO over 5.6m from 98m downhole (0.17% niobium pentoxide, 88.7ppm tantalum and 57.32ppm gallium), and peak TREO grades of 3,682ppm over 1m from 98m downhole.
Multiple Critical Minerals
Managing director Cadell Buss said the discovery of niobium proved the company’s tenements are part of a mineralised system hosting multiple critical minerals.
“This discovery is another significant milestone in the evolution of our company—we essentially started with a conceptual target about six months ago, and are now moving through systematic follow-up drilling, albeit for niobium rather than REE,” he said.
“This is now a very different proposition, and we have taken the decision to fund additional drilling of this exciting development in order to identify the extent of mineralisation and focus on the definition of a niobium resource.”
Drilling at the Mpyupyu target has been ongoing since August with a total of eight holes completed to date over two thorium and uranium anomalies with support from soil geochemistry values.
