Castle Managing Director, Stephen Stone commented 'The excellent continuity of high-grade zones within the broader 2.5km long Kambale graphite deposit has been confirmed by the recently completed, 30-hole, 2,662m RC infill and 4-hole, 365.2m diamond core drilling campaign.
Many holes returned impressive, multiple, thick, high-grade intercepts, several of which are the best yet obtained. These included 58m at 12.0% TGC (22CKR061), 69m at 10.3% TGC (22CKR062), 11m at 16.9% TGC (22CKR070) including 3m at 23.9%, 50.0m @ 10.7% TGC (22CKRR074), 23m at 17.1% TGC (22CKR075) and 25m at 12.9% TGC (22CKDD002).
The drill data is now in the hands of independent geologists who are on schedule to deliver a maiden JORC 2012 Mineral Resource estimate by the end of this month. Test work aimed at producing a bulk concentrate of commercially acceptable specifications is also well underway in Perth. The fast-track approach being undertaken at Kambale recognises that China dominates world graphite production and especially Battery Anode Material supply upon which most of the world's gigafactories are almost totally reliant. China's burgeoning electric vehicle market means it will require an increasing proportion of its production to meet internal demand.
This is propagating increasingly fierce international competition to secure non-China dependent, geostrategic, reliable and sustainable sources of graphite, which accounts for more than 30% of an EV battery's content. Graphite's 'Critical Mineral' status amongst those nations striving to achieve legislated clean energy objectives has become clearly evident. Kambale is emerging as a credible and well-timed graphite project ultimately aiming to service the expected surging demand and looming supply deficit.
Explorer and project incubator, Castle Minerals Limited (ASX: CDT) ('Castle' or the 'Company') advises that at least ten robust lenses of graphitic mineralisation containing high-grade zones with excellent continuity have been confirmed by a 30-hole, 2,622m RC infill and 4-hole, 365.2m diamond core drilling campaign at the rapidly emerging Kambale Graphite Project, Ghana ('Project'. Many holes returned impressive, multiple, thick, high-grade intercepts including 58m at 12.0% TGC (22CKR061), 69m at 10.3% TGC (22CKR062), 11m at 16.9% TGC (22CKR070) including 3m at 23.9%, 50m @ 10.7% TGC (22CKRR074), 23m at 17.1% TGC (22CKR075) and 25m at 12.9% TGC (22CKDD002).
Test work progressing
Four diamond core holes drilled to provide a 300kg representative sample for Phase 2 metallurgical test work at the Metallurgy Pty Ltd owned laboratory, Perth, also confirmed the integrity of the RC holes which they were designed to twin. The test work will comprise a series of beneficiation, flotation and grinding cycles on composited core aimed at producing a bulk quantity of as near-to commercial grade fine flake graphite concentrate as possible. This concentrate will then be transported to a specialist laboratory in Germany to determine its suitability to be upgraded into Battery Anode Material to be used in electric vehicle lithium-ion battery manufacturing. The concentrate will be assessed for its ability to be micronised, spheronised, purified and then coated along with several other critical performance parameters.
KAMBALE PROJECT BACKGROUND
The Kambale graphite deposit was identified in the 1960s by Russian geologists prospecting for manganese. They undertook a program of trenching and drilled 25 holes to a maximum depth of 25m. The mineralisation consists of north-east trending, sub-parallel zones of meta-sediment which is host to the graphitic schists. The Lower Proterozoic Birimian (2.2Ma) meta sedimentary rocks, namely phyllites, and quartz - biotite schists, generally trend north-easterly and dip between 50o and 75o to the north west. The schists are hosted mainly in granodiorite. The genesis of the flake graphite in Kambale is believed to be the result of high-grade metamorphism (amphibolite-granulite facies) which has converted trapped amorphous carbon into the characteristic fine crystalline layers. Castle reviewed the historical work and a wide-spaced, regional-scale electromagnetic survey dataset inherited from previous licence holder, Newmont Limited. This work outlined a roughly elongate, northsouth orientated, 10km-long region considered prospective for graphitic schist horizons which may host multiple lenses of graphite mineralisation, similar to what is already outlined from drilling and trenching at Kambale. These lenses or horizons can vary in length and be up to 50m wide, creating substantial deposits of graphite. Encouraged by firm graphite prices in 2012, Castle undertook three consecutive phases of drilling comprising RAB (251 holes, 5,621m), aircore (89 holes, 2,808m) and reverse circulation (3 holes, 303m). Mapping noted occasional outcrops of manganese and graphitic schist as well as graphite in termite mounds.
In 2012 Castle undertook a very limited program of bench-scale test work on RC chips. Thereafter, little work was undertaken until the more recent improvement in graphite prices prompted a re-evaluation of the Project in early 2021. In September 2021 Castle's new management team reported that preliminary test work on sub-optimal near-surface, weathered graphitic schists yielded very encouraging fine flake graphite concentrate grades of up to 96.4% and recoveries of 88%. A conventional multiple grind and flotation concentration flowsheet was used. Three excavated and composited samples provided for the test work graded 12.56%, 16.09% and 17.16% total carbon. In March 2022, a ground electromagnetic (HLEM) survey demonstrated a strong correlation between drill confirmed graphite mineralisation and zones of high conductivity. Several high conductivity zones extending well outside of the existing Inferred Resource boundary were highlighted indicating the possibility of extensions of the known graphitic schists into sparsely or undrilled areas. In late 2022 a 52-hole 5,353m RC program was undertaken to test the interpreted steep dipping, shallow conductive plates from the EM survey. The results confirmed that the majority of the plates where due to graphite mineralisation and that the graphite continued to depths of at least 100m and likely beyond. An Independently estimated JORC 2012 Exploration Target of 16.82 million tonnes to 50.46 million tonnes at a grade between 6.74%TGC and 10.40%TGC (Total Graphitic Carbon) was subsequently reported (refer ASX release 28 November 2022). The Exploration Target has been prepared and reported in accordance with the 2012 edition of the JORC Code. The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource. It is uncertain if further exploration will result in the estimation of a Mineral Resource. The Exploration Target confirmed that the Kambale represents a credible graphite deposit and provided added impetus for the accelerated evaluation approach now being taken.
Contact:
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About Castle Minerals Limited
Castle Minerals Limited is an Australian Securities Exchange (ASX: CDT) listed and Perth, Western Australia headquartered company with interests in several projects in Western Australia and Ghana that are prospective for battery metals (lithium and graphite), base metals and gold. The Earaheedy Basin project comprises the Withnell, Terra Rossa and Tableland sub-projects with the Withnell licence strategically located adjacent to the evolving World-Class ChinookMagazine zinc-lead project of Rumble Resources Ltd (ASX: RTR) and north of the Strickland Metals Limited (ASX: STK) Iroquois prospect. The Terra Rossa licences are east of the Thaduna copper deposit. The Beasley Creek project is prospective for gold and lithium and lies on the northern flanks of the Rocklea Dome in the southern Pilbara. The Success Dome project lies in the Ashburton structural corridor midway between the Paulsen's and Ashburton gold deposits and is prospective for gold and base metals. The Polelle project, 7km southeast of the operating Bluebird gold mine near Meekatharra, hosts a mainly obscured and minimally explored greenstone belt prospective for gold and possibly base metals whilst its partner , Wanganui project, is prospective for down-plunge high-grade gold shoots.
CASTLE MINERALS LIMITED 