Delta Lithium Unveils High-Grade Lithium and Robust Metallurgy at Yinnetharra

Yinnetharra Project Overview

Delta Lithium Limited (ASX: DLI) has provided a comprehensive operational update on its 100% owned Yinnetharra Lithium Project, located in the Gascoyne Lithium Province of Western Australia. The project spans a substantial 1,769 square kilometres and features a maiden Mineral Resource Estimate (MRE) of 25.7 million tonnes at 1% lithium oxide (Li2O) and 62 ppm tantalum pentoxide (Ta2O5) at the Malinda Prospect, announced in December 2023.

The recent drilling campaign focused on resource definition at Malinda has yielded encouraging high-grade lithium intercepts, including standout results such as 22.6 metres at 2.16% Li2O from 310 metres depth in hole YRRD126. These results are expected to enhance resource confidence and feed into an upcoming resource update.

Metallurgical Test Work Validates Processing Approach

Crucially, Delta Lithium has completed extensive feasibility-level metallurgical test work on the M1 deposit, which constitutes the majority of the Malinda resource. Over 40 composite samples were tested through more than 110 batch flotation tests, four locked cycle tests, and a 3.5-tonne pilot plant operation. The results confirm that high-grade spodumene concentrates of 5.5% to 6.0% Li2O can be produced at recovery rates ranging from 69.2% to 81.8%, with very low impurities.

The test work validated a Whole of Ore Flotation (WOF) flowsheet, a significant milestone that supports the technical and economic viability of the project. The pilot plant results, in particular, demonstrated the scalability of the flotation process and informed necessary adjustments such as the separation of process water circuits to optimize recovery.

Geological and Mineralogical Insights

The Malinda lithium mineralisation occurs mainly within three pegmatites, M1, M36, and M47, with mineralisation extending from surface to depths exceeding 300 metres. The M1 deposit is relatively homogeneous, dominated by spodumene, while M36 and M47 show more mineralogical variability, including lepidolite and amblygonite. This variability is being addressed through ongoing metallurgical variability testing to refine processing parameters.

Additionally, tantalum recovery opportunities have emerged, with preliminary test work indicating the potential to produce tantalum concentrates at approximately 50% recovery. This could add a valuable revenue stream to the project with modest flowsheet modifications.

Advancing Approvals and Exploration

Delta Lithium is actively progressing key approvals, including heritage and environmental surveys, with heritage surveys scheduled to recommence in April 2025. The company has submitted a Mining Lease application for the Malinda area and initiated Native Title negotiations. Environmental permitting discussions with regulators are planned for the March quarter.

Exploration activities continue across the broader Yinnetharra tenure, with two field teams conducting soil sampling, geological mapping, and target generation. While regional first-pass programs on joint venture tenements have yet to yield significant intercepts, the company remains optimistic about delineating new drill targets in 2025.

Outlook and Next Steps

Delta Lithium plans to ramp up its 2025 field program, update the Yinnetharra lithium Mineral Resource Estimate, and expand the tantalum resource outside current lithium wireframes. Further metallurgical and mining studies on the M36 and M47 deposits are underway, alongside finalising geotechnical and waste characterisation results for Malinda.

Managing Director James Croser highlighted the significance of the recent results, noting the emergence of a tantalum halo and the robust metallurgical performance of the M1 pegmatite, which underpins the early years of potential mine life. These developments position Delta Lithium well to advance Yinnetharra towards production readiness.