Junior explorer and project incubator, Castle Minerals Limited (ASX: CDT) ('Castle' or the 'Company'), advises that it has commenced a 4-hole, 370m diamond core drilling program at its emerging flagship Kambale graphite project, Ghana, to retrieve samples for Phase 2 test work aimed at producing a fine flake graphite concentrate that could be sold for use in the manufacture of electric vehicle battery anodes ('Project')(Fig 1). A follow-on 31-hole, 2,460m RC drilling program is aimed at better defining high-grade graphitic schist zones and for infill purposes to support a maiden JORC 2012 Mineral Resource estimate scheduled for end-Q1 2023.
Castle Managing Director, Stephen Stone commented 'We continue to fast-track the emerging Kambale graphite project with a diamond core drill program commencing just days after reporting results from a recently completed RC drilling campaign which successfully extended the Kambale deposit's north-south axis to 2.5km.' We plan to have the core drilling and a follow-on 31-hole infill RC drilling completed by early-December and core samples in Perth ready to start Phase 2 test work by Christmas. The test work will aim to produce a fine flake graphite concentrate suitable for use in the manufacture of electric vehicle battery anodes. Our consultants should deliver an independent Exploration Target estimate by endNovember and we plan to provide a maiden JORC 2012 Mineral Resource by the end of Q1 2023. So, just with Kambale alone there is a lot for Castle's shareholders to look forward to in the near-term.'
Castle recently reported results from the final 29 holes of a 52 hole, 5,353m RC drill program where mineralisation comprising a series of sub-parallel graphitic schist zones was confirmed to extend northsouth for 2.5km. Several of the RC holes returned thick, high-grade and multiple intercepts of graphite with results overall reinforcing expectations that ultimately a series of higher-grade zones will be outlined within a broader but still well mineralised envelope.
Core drilling and test work
The diamond drill core will be obtained from four locations providing a good representation of the graphite schist material and its variability. Phase 1 test work was conducted on near-surface, trench excavated material where weathering of the graphite and gangue material will have impacted the mineralogy and subsequent concentration process. The weathering profile is observed to extend to a depth of 30-40m below surface. Fresh graphitic schist has been drilled to a vertical depth of at least 100m and remains open at depth. Phase 2 test work will comprise a series of beneficiation, flotation and grinding cycles on composited core to develop a preliminary process flowsheet design aimed at producing a commercial grade fine flake graphite concentrate for possible application in electric vehicle battery anode manufacture. The rock density, structural integrity and other attributes of the core will be measured for use in the proposed Mineral Resource estimate and in any mining scoping studies, should they be warranted.
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. A subsequent report noted 'two main zones of graphitic schists averaging around 10% to 15% graphite within which there were higher grade zones and that the graphite is the flaky variety with fine crystals (usually less than 0.25mm).' (Report on the Geology and Minerals of the South Western Part of the Wa Field Sheet, Pobedash, I.D. 1991). The mineralisation consists of north-east trending, sub-parallel zones of graphitic schists found within the Lower Proterozoic Birimian (~2.2Ma) Wa-Lawra Greenstone belt. The schists generally trend northeasterly and dip between 50o and 75o to the north west. They are hosted mainly in granodiorite to the north and biotite and quartz mica schists in the south. The genesis of the flake graphite in Kambale is believed to be associated with high-grade metamorphism (amphibolite-granulite facies) where metamorphic derived CO2 rich hydrothermal fluids have infilled shear related dilational zones and formed the graphite during the extreme metamorphic event. Castle has reviewed this historical work and a wide-spaced, regional-scale electromagnetic survey dataset inherited from previous licence holder, Newmont Limited. This 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 which was not an ideal sample. The work returned mixed results. 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 reported that preliminary test work on sub-optimal, trench excavated nearsurface, weathered graphitic schists yielded very encouraging fine flake graphite concentrate grades of up to 96.4% and recoveries of 88% using a conventional multiple grind and flotation concentration flowsheet. 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 July 2022 Castle completed and subsequently reported in November 2022 the results of a 52-hole, 5,353m RC drill program which, amongst other positive developments, confirmed multiple, subparallel graphitic schist zones to extend for at least 2.5km north-south and a strong correlation between interpreted conductor plates and mineralization
Contact:
Stephen Stone
Managing Director
E: stone@castleminerals.com
T: +61 (0)418 804 564
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 encompasses terrane prospective for base and precious metals in the Earaheedy and Yerrida basins base metals provinces. The project comprises the Withnell, Terra Rossa and Tableland sub-projects. The Withnell licence is adjacent to the evolving Chinook-Magazine 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 lies on the northern flanks of the Rocklea Dome in the southern Pilbara where orogenic-style, structurally controlled gold targets within the various Archean sequences are being targeted. Unexpected lithium anomalism is also being followed-up. The Success Dome project lies in the Ashburton structural corridor and is located midway between the Paulsen's and Ashburton gold deposits. It 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. The Wanganui project, 15km south-west of the operating Bluebird gold mine, presents an opportunity to test for down-plunge and along strike extensions to the existing Main Lode North and South deposits and similar targets. The Wilgee Springs project, along strike from and within the same metamorphic belt as the world-class Greenbushes lithium mine 25km to the south, provides an opportunity to explore for spodumene bearing pegmatites beneath a lateritic cover that has previously hampered exploration. The Woodcutters project, is prospective for lithium bearing pegmatites, 25km southeast of the Bald Hill lithium mine and 25km northwest of the Buldania lithium deposit. The Woomba Well project will be evaluated for lithium bearing pegmatites. The Great Southern Graphite project comprises two granted licences encompassing the historical Kendenup graphite workings and the adjacent Martagallup graphite occurrences and one application covering a graphite occurrence at Mt. Barrow. In Ghana, West Africa, Castle's substantial and contiguous tenure position in the country's Upper West region encompasses large tracts of highly prospective Birimian geological terrane, the host to many of West Africa's and Ghana's multi-million-ounce gold mines. The emerging Kambale graphite project also lies on the Ghana tenure. Drilling and test work to date have indicated that it is a sizable open-ended deposit with several favourable attributes to warrant its advance
Cautionary Statement
All of Castle's projects in Australia are considered to be of grass roots or of relatively early-stage exploration status. There has been insufficient exploration to define a Mineral Resource. No Competent Person has done sufficient work in accordance with JORC Code 2012 to conclusively determine or to estimate in what quantities gold or other minerals are present. It is possible that following further evaluation and/or exploration work that the confidence in the information used to identify areas of interest may be reduced when reported under JORC Code 2012.
Forward Looking Statement
Statements regarding Castle's plans, forecasts and projections with respect to its mineral properties and programs are forward-looking statements. There can be no assurance that Castle's plans for development of its mineral properties will proceed. There can be no assurance that Castle will be able to confirm the presence of Mineral Resources or Ore Reserves, that any mineralisation will prove to be economic or that a mine will be successfully developed on any of Castle's mineral properties. The performance of Castle may be influenced by a number of factors which are outside the control of the Company, its Directors, staff or contractors.
CASTLE MINERALS LIMITED 