Castle Managing Director, Stephen Stone commented 'The Kambale graphite deposit continues to deliver with the final batch of RC drilling results extending its footprint to 2.5km north to south and identifying new areas with good continuity. Several holes intercepted additional multiple graphitic zones such as 22CKRC05 which returned 2.14m at 8.1% TGC from 47m and then a very solid 45m at 11.2% TGC from 66m. Core drilling to obtain samples for the next phase of test work to produce a battery-grade concentrate will begin mid-November followed by a brought forward 2,500m RC program to better define higher grade zones. We will deliver an independent JORC Exploration Target estimate in coming weeks and a Mineral Resource estimate is scheduled for Q1 2023. Graphite's status as a critical mineral is now endorsed by several governments and its use in anodes for electric vehicle batteries alone is substantially increasing concentrate demand and bolstering prices.
Next steps
1. Receive in coming weeks an independent Exploration Target estimate.
2. Prepare for and complete in Q4 2022 a diamond core drilling program to retrieve samples for phase 2 test work.
3. Transport core samples to Perth and commence in Q4 2022 Phase 2 test work.
4. Commence and complete in Q4 2022 a ~2,500m high-grade zone focused infill RC drill program.
5. Receive RC drilling results and deliver a JORC 2012 Mineral Resource estimate Q1 2023.
6. Receive Phase 2 test work results and preliminary process flow sheet design Q1 2023.
7. Provide test work generated concentrate to specialist consultants for assessment of refining capability and marketing analysis Q2 2023.
Junior explorer and project incubator, Castle Minerals Limited (ASX: CDT) ('Castle' or the 'Company'), advises that it has received results from the final 29 holes of its recently completed 52 hole, 5,353m RC drill program at its flagship Kambale Graphite Project, Ghana ('Project')(Figs 1 to 4). Mineralisation comprising a series of sub-parallel graphitic schist zones has been extended to 2.5km north-south and spans up to 0.5km east-west. It remains open to the north and south and is untested to depth. Several of the new holes returned additional thick, high-grade and multiple intercepts of graphite such as in 22CKRC052 which intersected 14m at 8.1%TGC from 47m and then a very solid 45m at 11.2%TGC from 66m. Results from all of the holes reinforce expectations that ultimately a series of higher-grade zones will be outlined within a broader but still well mineralised envelope. The RC drill hole locations were mostly guided by a ground HLEM geophysical survey that identified numerous conductive plates, many of which coincide with previously identified graphitic schist. Drilling of those moderate to steeply dipping plates located outside of the prior defined graphitic schist, in most but not all cases, confirmed extensions and/or parallel zones to mineralisation and therefore the reliability of HLEM as an exploration tool in and around the Kambale camp. Mapping in the broader Kambale area has indicated that a number of other graphitic schists may be present
Core drilling and test work
Core drilling of selected zones in order to retrieve fresh (unweathered) ore samples from higher-grade zones for the second phase of metallurgical test work is being planned to commence in mid-November. Test work will be undertaken in Perth and will comprise a series of beneficiation, flotation and grinding cycles on composited core to develop a preliminary process flowsheet design that will produce a commercial grade concentrate. This test work concentrate will then be provided to specialists who will determine if it has the right physical and chemical characteristics to be sold into one or more of several concentrate markets, such as EV battery anode manufacturing.
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 meta-sediment which is host to the graphitic schists. The Lower Proterozoic Birimian (~2.2Ma) meta sedimentary rocks, namely phyllites, Kambale Graphite Project: Final RC drilling results Page 6 of 19 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 this 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 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 near-surface, 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. These areas were tested in late 2022 by a 52-hole 5,353m RC program.
Graphite market
The graphite market is diverse across industrial, metallurgical, chemical and specialised areas with each sector requiring graphite concentrates with specific qualities. Deposit type, size and geometry, flake size, flake shape, grade, impurities, capital and operating costs, proximity to specific markets, supply logistics, jurisdiction, fiscal regime and many other factors all combine to determine the commercial viability of a particular deposit. The current medium to long term outlook for the broader graphite concentrates market is one of escalating demand and a looming supply deficit driven in particular by its un-substitutional use in the fastgrowing EV battery and stationary power storage sectors. There is an increasing proportion of natural graphite, over synthetic graphite, being used in battery anode manufacture which also requires a fine flake graphite as the primary raw material. Hence, prices for fine flake graphite concentrates have shown a steady upward trend in the past year. The reader is directed to numerous recent publications, conference proceedings, market research papers and corporate websites of companies engaged in graphite exploration, project development or production for informed commentary and analysis of the graphite market.
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
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
Competent Persons Statement
The scientific and technical information in this Report that relates to the geology of the deposits and exploration results is based on information compiled by Mr Stephen Stone, who is Managing Director of Castle Minerals Limited. Mr Stone is a Member of the Australian Institute of Mining and Metallurgy and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. Mr Stone is the Qualified Person overseeing Castle's exploration projects and has reviewed and approved the disclosure of all scientific or technical information contained in this announcement that relates to the geology of the deposits and exploration
CASTLE MINERALS LIMITED 