Delta Lithium’s Mt Ida Resource Hits 14.8 Mt with 1.21% Lithium and High Rubidium

Resource Upgrade Highlights Strategic Rubidium Potential

Delta Lithium Limited (ASX – DLI) has delivered a significant update to its Mt Ida Lithium Project, located in Western Australia’s Eastern Goldfields. The December quarter saw the company announce a refreshed Mineral Resource Estimate (MRE) of 14.8 million tonnes at 1.21% lithium oxide (Li2O), complemented by tantalum and notably high-grade rubidium oxide (Rb2O). This positions Mt Ida as a globally significant source of rubidium, a critical mineral gaining traction in advanced technology sectors.

The updated MRE includes 7.7 million tonnes classified as Measured and Indicated resources, reflecting increased confidence driven by both Delta’s drilling and ongoing gold drilling by Ballard Mining, which provides valuable data to refine resource models. The delineation of 0.5 million tonnes in the Measured category is particularly important, as it de-risks early mining potential and supports near-term development plans.

Metallurgical Advances Unlock New Revenue Streams

Metallurgical testwork has confirmed that rubidium can be efficiently recovered during the lithium ore flotation process, with rubidium recoveries averaging around 90% in the mica pre-float stage. This breakthrough means rubidium can be produced as a co-product without major alterations to the existing processing flowsheet, potentially enhancing project economics significantly.

Further downstream processing studies are underway, with early results indicating the feasibility of producing high-purity lithium carbonate and rubidium carbonate, alongside potassium sulphate as a byproduct. Given rubidium’s expanding applications in quantum technologies, defence systems, and biomedical fields, its inclusion adds a strategic dimension to Mt Ida’s value proposition.

Exploration Momentum at Yinnetharra and Mt Ida

Delta continues to advance exploration at its Yinnetharra Lithium Project, with a reverse circulation drilling campaign targeting high-priority prospects along a 20-kilometre prospective corridor. The Jameson prospect, with an existing resource of 0.8 million tonnes at 1.66% Li2O, remains open at depth and is a key focus for resource growth. Structural studies have identified compelling targets associated with fold hinges and faults, which have yet to be drill tested.

Meanwhile, the Mt Ida Project benefits from incremental exploration data courtesy of Ballard Mining’s gold drilling, which enhances resource confidence and classification. The project is fully permitted for both open pit and underground mining, positioning Delta well for development advancement.

Robust Financial Position Supports Growth

Delta Lithium reported a strong cash balance of $54 million at quarter-end, supplemented by listed investments valued at approximately $108 million. This financial strength provides the company with flexibility to pursue growth opportunities within its lithium portfolio and beyond, while continuing to fund exploration and development activities at Mt Ida and Yinnetharra.

Managing Director James Croser highlighted the strategic benefits of the recent gold asset demerger into Ballard Mining, which not only bolstered Delta’s balance sheet but also delivers ongoing exploration synergies. The company’s focus remains on unlocking maximum value from its lithium and critical minerals assets amid a tightening global supply landscape.