Castle Managing Director, Stephen Stone said 'We are extremely pleased that recently completed electrochemical tests have confirmed Kambale graphite's status as a very attractive base for the manufacture of lithium-ion electric vehicle battery anodes and a range of other high-value primary and secondary applications.
Purified Kambale graphite met a range of chargeability, stability and other critical performance benchmarks during tests undertaken in an accredited facility in Germany. In rapid succession Castle has defined a 22.4 million tonne resource grading a very respectable 8.6% TGC and shown it can be upgraded into a valuable 95% LOI graphite concentrate using a conventional flowsheet.
In February this year Castle reported that it had successfully purified this concentrate to an above industry specification of 99.97% LOI, again using a conventional process. This is all happening at a time when the world needs considerably more fine natural flake graphite to underpin forecasts of very strong growth in the uptake of electric vehicles.
Recent third party offtake deals between non-Chinese upstream producers of primary natural graphite concentrate and downstream manufacturers of natural graphite conductive additives for anodes, cathodes and other secondary battery chemistries are evidence of a paradigm shift in markets away from a high dependency on China supply. The USA and EU have established billion dollar initiatives to help establish independent supply chains of critical minerals such as graphite. Kambale would therefore be ideally timed and well placed to service both existing and also these new emerging markets. Recent meetings with the Ghana government confirmed its strong support for any development at Kambale as part of a broader ambition it has to establish West Africa's first critical minerals hub. Castle's view remains that the graphite market is fundamentally very robust and graphite is definitely a commodity to watch this year and into the longer term.'
Castle Minerals Limited (ASX: CDT) ('Castle' or the 'Company') advises that electrochemical tests on material from its Kambale Graphite Project, Ghana ('Project') have confirmed its high performance characteristics and suitability for use in the manufacture of lithium-ion battery anodes and in other battery chemistries and formats.
This represents another landmark development for the Project which Castle has rapidly progressed over the past two years. It has now: confirmed an open-ended 22.4 million tonne resource (JORC 2012) grading a very respectable 8.6% Total Graphitic Carbon ('TGC') containing 1.9 million tonnes of graphite; demonstrated that mined material can be upgraded using a conventional flowsheet to a valuable and saleable 95% Loss on Ignition ('LOI') concentrate and purified the natural flake concentrate to an above benchmark 99.97%LOI containing no impurities of concern and again using a conventional flowsheet
Electrochemical test work
Electrochemical test work on purified Kambale natural flake concentrate was undertaken at an accredited specialist facility in Germany under the supervision on ProGraphite GmbH ('ProGraphite'). ProGraphite had previously purified to 99.97% LOI a natural flake concentrate grading 95% LOI produced by Perth-based, Metallurgy Pty Ltd, under the supervision of Independent Metallurgical Operations Pty Ltd ('IMO'). The downstream processing tests used a sample of micronised, spheronised and purified (99.97% LOI) graphite ('SPG') provided by ProGraphite. This uncoated SPG graphite material was specially formed and a T-cell produced which was then electrochemically performance evaluated in a simulated lithium-ion battery configuration (Swagelok T-Cell). A comprehensive range of physical and electrochemical properties were evaluated and measured under a variety of controlled conditions. These provided a series of outputs relating to the chargeability, durability, stability, reversible capacity and other parameters of Kambale flake graphite SPG material. The Kambale SPG sample was not coated for the lab cell testing. Coating technology is the final process in producing a coated spherical graphite ('CSPG') anode product and would normally be expected to improve on the already high-quality performance results obtained. The process varies by battery original equipment manufacturer ('OEM') and is done to control BET (surface area / porosity) to end user specifications. It is stressed that whilst these are simplified laboratory-scale tests they provide critical indicators for battery OEMs to consider when additional lab and field battery testing is completed. Individual battery OEMs usually undertake their own 'qualification' tests prior to entering into firm sales contracts that will also consider quality assurance, logistical performance and packaging integrity
Initial Economic Assessment Underway
Using all of the valuable information obtained over the past two years Castle and its various consultants are working to identify an optimal, viable long term development strategy for Kambale. This is being guided by an understanding of the graphite market obtained from a variety of sources and also aligned with aspects of the Project's location, available infrastructure, logistics and jurisdictional environment. Once completed, this high-level initial economic assessment will provide a platform to move the Project through various study phases to a Definitive Feasibility Study, if warranted. At this early stage a development at Kambale at this stage is likely to take the form of a low entry capital cost, initially campaign-mined and scalable, modularised operation. This will produce a commercially qualifiable and saleable bulk natural fine flake graphite concentrate on site as well as a range of other downstream high-value specialist graphite products and bi-products
Ghana government support
Castle Managing Director, Stephen Stone, this month met with several senior Ghana government officials, local investment funds and contractors. All expressed a high level of support for the Kambale Graphite Project especially given Ghana's ambition to establish a local critical minerals based industry hub. In this regard the Kambale Graphite Project is viewed as being strongly compatible with the Atlantic Lithium Ltd (ASX: A11) Ewoyaa lithium project on Ghana's south coast. The Ghana government, through its Mineral Income Investment Fund, recently invested a total of US$32.9M in Atlantic and its Ghanaian subsidiaries to expedite the development of Ewoyaa. The recent commencement of development at the Cardinal Namdini Mining Ltd owned Namdini Gold Mine in northern Ghana and the likelihood of construction commencing this year at the Black Volta Gold project, just 40km north of Kambale, will see a major boost to the availability of mining contractor and other key services into the region. These will add to the already excellent infrastructure available in the vicinity of Kambale which includes 40% renewables-based grid power passing close to the Project
ABOUT THE KAMBALE GRAPHITE PROJECT
Ghana Ghana has a well-established mining industry including several Tier-1 gold mining operations. It is now Africa's largest gold producer and the World's sixth largest. Accordingly, it has a well-trained and very capable workforce supported by an excellent mining services and supply sector. It is a safe and politically stable jurisdiction based on the democratic Westminster system of government. Logistics, infrastructure and licencing The Project is located 6km west of the Upper West region capital of Wa which is 400km north, via good sealed roads, of Kumasi. From Kumasi it is approximately 240km south east by rail or road to the international port of Tema, 30km west of the capital Accra, which provides direct access to global export markets. The Wa region has an excellent infrastructure including a commercial airport only a few kilometres from the Project, numerous well maintained sealed and unsealed roads, plenty of potable water and reliable grid power largely fed with electricity generated by the 400MWh Bui hydroelectric dam. These will all combine to represent a large saving in Project establishment capital costs. The 149km2 Kambale Graphite Project licence is held by 100% owned Ghanaian subsidiary, Kambale Graphite Limited ('KGL'). The Government of Ghana has the right to a 10% free carried interest in all licences and is entitled to a 5% Gross Royalty on production. Geology 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 characteristic fine crystalline layers. The Kambale graphite deposit was identified in the 1960s by Russian geologists prospecting for manganese. They undertook a limited programme of trenching and shallow drilling. 2012 drilling 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). This work confirmed several zones of moderately to steeply dipping, north-east trending graphitic schists hoisted mainly in granodiorites. A JORC Code 2006 MRE was also undertaken. Castle also undertook a very limited programme of bench-scale test work on RC chips. Thereafter, little work was undertaken until the more recent improvement in graphite prices prompted a reevaluation of the Project in early-2021.
Authorised for release to ASX by the Board of Castle Minerals Limited: Stephen Stone Managing Director stone@castleminerals.com +61 (0)418 804 564
ABOUT CASTLE MINERALS
Castle Minerals Limited is an Australian Securities Exchange (ASX: CDT) listed and Perth, Western Australia headquartered company with interests in several projects in Ghana and Western Australia that are prospective for Battery Metals (graphite and lithium), base metals (zinc, lead and copper) and gold. In Ghana, West Africa, the emerging flagship Kambale Graphite Project owned by 100% Ghanaian subsidiary, Kambale Graphite Limited, is progressing through technical and commercial evaluation for the production of battery grade material to be used in lithium-ion battery manufacture. Castle's 100% owned Ghanaian subsidiary, Carlie Mining Ltd, holds a 2,686km2 tenure position in the same Upper West region. This 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. It has delineated several advanced gold exploration targets including at Kpali, Bundi and Kandia. It also retains a 4% net smelter precious metal royalty over the Julie West licence, a key component of Azumah Resources Limited's nearby Black Volta gold project. In Western Australia, The Earaheedy Basin project comprises the Withnell and Terra Rossa subprojects. The Withnell licence is 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 have additional prospectivity for copper. 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 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 the Wanganui project is prospective for down-plunge high-grade gold shoots. Both have been farmed-out to Great Boulder Resources Limited (ASX: GBR) The Wilgee Springs project, along strike from and within the same metamorphic belt as the worldclass Greenbushes lithium mine 25km to the south, is prospective for spodumene bearing pegmatites as is the Woodcutters project, 25km south east of the Bald Hill lithium mine and 25km north west of the Buldania lithium deposit. The Woomba Well project is similarly prospective for lithium bearing pegmatites.
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 programmes 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 Statements
The scientific and technical information in this release 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 release that relates to the geology of the deposits and exploration. Information in this release that relates to the geological interpretation and Mineral Resources is based on information compiled by Jamie Logan, a full time employee of Palaris Australia Pty Ltd, under the direction and supervision of Dr Allan John Parker. Dr Parker is a Member of the Australasian Institute of Geoscientists, an employee of Palaris Australia Pty Ltd, Director of Geosurveys Australia Pty Ltd, a Non-Executive Director of Centrex Limited and was formerly Managing Director of Lincoln Minerals Limited. Dr Parker has sufficient experience relevant to the styles of mineralisation and to the activities which are being presented to qualify as a Competent Person as defined by the JORC code, 2012. Dr Parker consents to the release of the information compiled in this release in the form and context in which it appears. Information in this release that relates to metallurgical test work managed by Independent Metallurgical Operations Pty Ltd ('IMO') is based on, and fairly represents, information and supporting documentation compiled and/or reviewed by Mr Peter Adamini BSc (Mineral Science and Chemistry) who is a member of The Australasian Institute of Mining and Metallurgy (AusIMM). Mr Adamini is a full-time employee of IMO who has been engaged by Castle Minerals Ltd to provide metallurgical consulting services. Mr Adamini consents to the inclusion in this release of the matters based on his information in the form and context in which it appears. Mr Adamini advises that information in this release that relates to metallurgical test work undertaken or supervised by ProGraphite GmbH is based on, and fairly represents, information and supporting documentation provided by ProGraphite GmbH and/or its subcontractors.
CASTLE MINERALS LIMITED 
