Castle Minerals Limited has commenced a high-resolutions, ground electromagnetic geophysics survey to measure the extent of graphite mineralization of the Kambale graphite deposit in the north-west Region of Ghana.
The survey, which is expected to last for two weeks, will provide guidance to target drilling which includes identifying specific areas likely to achieve quality graphite samples for onward diamond drilling.
“Survey results will enable us to better outline and estimate how extensive the deposit is and plan drilling to identify zones of the best quality material and obtain diamond core samples of fresh material for the next phase of test work.”
Stephen Stone, MD, Castle Minerals
The geophysical survey was launched shortly after Castle Minerals received positive graphite concentrate grades from preliminary metallurgical test work at Kambale. The study was conducted on “near-surface, weathered graphitic schists in 2021 that achieved fine flake graphite concentrate grades of up to 96.4 per cent and recoveries of 88 per cent,” Stephen Stone said.
Castle’s Kambale graphite project in Ghana is West Africa’s only known graphite deposit of decent scale. The company stated that Ghana is an established and safe mining jurisdiction with a myriad of advantages including a highly skilled workforce, a strong mining services sector and excellent infrastructure.

The geophysical survey will be undertaken on lines that are 100m to 200m apart with readings taken every 25m in order to achieve a high-quality sub-surface picture of the graphitic shear zones, according to the statement. The survey was designed using parameters set through a series of wide-spaced, shallow, rotary air blast drill hits over a north-south strike of approximately 4km.
Importantly, the Rotary Air Blast graphitic shale hits are coincident with a low-resolution airborne electromagnetic anomaly that extends for several additional kilometres from known mineralization to both the north and south. The areas are yet to be drill tested for the presence of the targeted graphitic schist unit.
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Undergoing three consecutive phases of drilling in the initial stages in 2012, two of the drilling results affirmed a Mineral Resource estimate of 14.4Mt at 7.2%C (graphitic carbon) for 1.03Mt contained graphite. The two initial phases of drilling showed extended mineralization of 1.25 km while with the three phases of drilling combined, the extent of mineralization reached a strike length of 2km.
Originally motivated by increased graphite prices in 2012, Castle began taking a closer interest in the Kambale graphite deposit. Its exploration efforts kicked off with a detailed review of historical work including studying a regional-scale electromagnetic survey dataset conducted by Newmont that identified a 10km long region prospective for graphite.
Castle Managing Director, Stephen Stone, said: “Nearly all traditional sectors of the graphite market and the emerging EV sector are experiencing strong growth and looming concentrate supply constraints, so we are understandably very keen to fast-track Kambale.”
Currently, the consensus is that the multi-sector global demand for graphite is supportive of a medium to long-term positive outlook for the mineral. Therefore, with a geophysical survey underway and more drilling scheduled on the calendar– Castle will be looking to add more tonnes to its maiden resource estimate.
Castle Minerals, through its 100 per cent-owned subsidiary, Carlie Mining which is registered in Ghana holds the prospecting licence for the project’s location. The Kambale licence is currently progressing through a renewal process, nearing its final stages.
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