Aim-listed lithium exploration and development company Atlantic Lithium has upgraded its mineral resource estimate (MRE) for the Ewoyaa lithium deposit within the Cape Coast lithium portfolio, in Ghana, to 35.3-million tonnes at 1.25% lithium oxide (Li₂O), including 28-million tonnes in the measured and indicated categories. 

“The resource upgrade represents a significant derisking milestone for the company, with 79% of the resource now in the higher confidence measured and indicated categories, with potential for further exploration growth. This, in addition to the larger overall tonnage, will provide the opportunity to evaluate extended mine life and increased throughput to enhance project economics,” Atlantic Lithium interim CEO Lennard Kolff said on February 1. 

He added that a definitive feasibility study was well-progressed and targeted for release during the second quarter. 

That 79% of the resource that now falls withing the measured and indicated categories is made up of 3.5-million tonnes at 1.37% Li₂O in the measured category and 24.5-million tonnes at 1.25% Li₂O in the indicated category. 

Atlantic said this was the first time that it had been able to report measured resources for the project, with additional indicated resources being converted from the inferred category, highlighting “strong geological and mineralisation continuity, favourable for ongoing studies”.  

“Our goal was to convert the inferred to indicated category, define the first one to two years of planned production to measured category and increase the overall resource scale. We have . . . achieved all our goals," Kolff said. 

Atlantic believed that there was significant exploration upside within the immediate resource area with some pegmatites open along strike and at depth. Only 15 km² has drilled to date within the broader 560 km² Cape Coast lithium portfolio. 

The MRE upgrade is based on a total 137 153 m of drilling, including a 47 000 m programme completed last year. The drilling is comprised of 120 845 m of reverse circulation and 16 308 m of diamond core drilling. 

The results of a prefeasibility study (PFS) released in September 2022 showed potential in terms of the financial outcomes for a two-million-tonne-a-year operation, producing an average of about 255 000 t/y of 6% Li₂O spodumene concentrate over a 12.5-year operation based on a 30.1-million tonnes at 1.26% Li₂O MRE. 

The PFS showed life-of-mine revenues exceeding $4.84-billion at a capital cost of $125-million and with cash operating costs of $278/t of 6% lithium spodumene concentrate. 

Kolff said metallurgical test work to date has delivered high-purity, low contaminants of about 6% Li₂O coarse spodumene concentrate using simple gravity-only processing.  

“The company has transitioned from explorer to developer, with Ewoyaa funded to production through our agreement with Piedmont, key senior personnel recently recruited, and our mining licence application submitted," he added.