Promising signs from ASX-listed battery metals explorer

Firetail Resources’ Yalgoo Lithium Project in WA confirms Lithium, Caesium, Tantalum and indications of high-grade Rubidium Located around 110 km west of Mt Magnet in the Murchison region of Western Australia, Yalgoo, highlights of Firetail Resources (ASX: FTL) exploration drilling so far include:

• LCT pegmatites, with up to 0.28% lithium oxide, 1,860 parts per million Caesium (CS) and 92ppm Tantalum (Ta).

• High-grade Rubidium at multiple depths

Firetail’s executive chairman Brett Grosvenor says the maiden Yalgoo drilling campaign, covering an area of just 1km by 2km, has only “scratched the surface” of the broader 25km-plus “goldilocks” zone of LCT pegmatites. This was identified using Firetail’s program of surface mapping and geochemical sampling.

“Although the Lithium results from this area were not as high-grade as expected, we are pleased to have returned some high-grade Rubidium results from the campaign,” Grosvenor says.

“This mineralisation is near surface and confirms a fertile district of Rubidium mineralisation, trace elements normally associated with lithium exploration.”

Key features of the maiden drill program

A total of 49 Reverse Circulation (RC) holes were completed for 1,932 metres in the Phase 1 drilling campaign. These focused on five prospective pegmatites defined by Firetail's surface mapping and geochemical sampling. 14 holes returned assays over 0.15 %Rb with a standout intersection of 10m @ 0.44% Rb from 10m returned from the eastern fold hinge of one of the defined LCT pegmatite target areas. This drill result has notable geological similarities to the Johnson Well Rubidium prospect, 8km southeast of Firetail’s Yalgoo project. This found, in RC chip samples, potassium feldspar, albite, muscovite, biotite, tourmaline, apatite ± pollucite ± lepidolite ± zinnwaldite ± cassiterite ± beryl ± garnet. According to Firetail management:

Firetail has interpreted this Rubidium-bearing pegmatite to strike North-West, and as these were first-pass scout holes, it believes the holes to the north and south have not effectively tested the northern and southern extensions of this high-grade result. As such, this high-grade intersection remains open along strike and at depth.

Yalgoo Lithium Project

Drill collar plan, showing outlines of outcropping LCT Pegmatites.

Why does this matter?

Rubidium is considered to be one of the highest-value critical metals, with Rubidium Carbonate trading at an average price of US$1,200 per kilogram Potential applications for decarbonisation as an additive for efficiency improvements in solar energy and battery technologies. Rubidium is found to improve the power conversion efficiency of perovskite solar cells by up to 20%, with the potential to offer more cost-effective solar energy. Further studies have shown the effectiveness of Rubidium as an electrolyte additive for improving the performance of hard carbon anodes in sodium-ion batteries.

What’s next?

• Refining the exploration program following the maiden campaign at Yalgoo, the Firetail team will focus on follow-up exploration planning to expand on these early results.

• Initial drilling of the Johnson Well Rubidium pegmatite, whose northern extension reaches onto Firetail tenement E59/2364

• Target Generation - review geochemistry and first-pass drilling to define and rank high-priority targets, and plan follow-up work programs

Firetail is expected to provide further updates on exploration activities across its projects as further information and developments occur.