Kambale Graphite Project
More Graphite Zones at Kambale
- After successful EM survey leading to a very successful 52-hole, 5,353m RC drilling campaign in Sep-Nov 2022, an Independent JORC 2012 Exploration Target estimate delivered.¹
- Highlights Kambale as a large-scale deposit that remains open to the north, south and to depth.
- Underpins plans to assess Kambale as a producer of a fine flake graphite concentrate to be assessed for possible application in the production of electric vehicle battery anode material.
- 4-hole diamond drill core program underway (one hole completed) with core to be used in Phase 2 test work.
- 31-hole, 2,460m RC follow-on infill drilling program designed to better define higher grade zones and facilitate a maiden JORC 2012 Mineral Resource estimate around end-Q1 2023.
- Field team undertaking a broad reconnaissance of the Kambale region to evaluate for additional graphite occurrences.
- Sahara Mining Services appointed to provide independent QA / QC review and JORC Exploration Target range estimate.
- Test work proposal executed with IMO Pty Ltd, Perth.
- CSA Global retained to provide graphite specific technical assistance.
- Market commentary continues to forecast a substantial graphite supply deficit over the next decade with increased demand coming mainly for fine flake graphite concentrates for use in the manufacture of EV and stationary batteries. Fine flake graphite prices continue to firm on forecasts for a looming supply deficit.²
|Domain||Min Tonnage (Mt)||Max Tonnage (Mt)||Min Grade (%TGC)||Max Grade (%TGC)|
¹ Cautionary Statement: 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.
² FastMarkets: NewGen Long Term Forecast – 27.10.2022
Castle Managing Director, Stephen Stone commented: “The independently estimated Exploration Target of 16.82 to 50.46 million tonnes at a grade range between 6.74% and 10.40%TGC indicates the Kambale Graphite project has a possible scale and grade to warrant progression to the next phase of assessment. Phase 2 test work using samples obtained from the now underway diamond core drilling will assess if a commercial grade concentrate can be produced which would then be evaluated for possible use in the manufacture of electric vehicle battery anodes. A follow-on infill RC drilling program will primarily focus on defining recently confirmed multiple higher grade graphitic zones and will also facilitate a maiden JORC 2012 Mineral Resource for delivery around end-Q1 2023. In addition to the large amount of news flow in coming months from the Kambale Graphite Project there will also be a steady stream of updates from Castle’s battery and future metals projects in Western Australia.”
|Hole||Width||Total Graphitic Carbon||From|
|5% TGC cut-off. 2m max internal dilution. Intercepts are not true widths.|
In 2012 Castle commenced graphite exploration on the Wa Project. A historic graphite occurrence about 5km west of Wa was first noted by Russian geologists whilst prospecting for manganese in the 1960’s.
Castle located the historic trenches and completed mapping, RAB, aircore and RC drilling during the first half on 2012. In July 2012 Castle announced a maiden resource estimate for its Kambale Graphite of 14.4mt @ 7.2% C (graphitic carbon) for 1.03mt contained graphite (Inferred Resource). Flotation testwork was conducted on samples of fresh and weathered graphitic schist from the Kambale deposit. Microscopic examination of some flotation concentrates indicated that the graphite flakes were up to 250 microns long.
Exploration has only tested a small part of the interpreted graphtic schist horizon at Kambale and excellent potential exists to substantially increase the current resource. RAB intercepts outside of the current resource area include email@example.com% TGC and 19m @ 7.64% TGC highlighting the prospectivity of the area.
Rougher flotation tests on the fresh and weathered ore samples gave a maximum concentrate grade of over 50% graphite but at low recoveries. In the size fractions coarser than 150 microns, a high proportion of graphite loss to the scavenger tailings was observed. The -150+75 micron size fraction, concentrates 1 and 2 combined, gave a 50% graphite grade at 40% recovery with 30% lost to the final tails. The -75 micron fraction gave the highest recovery (>90%), as expected from a greater degree of graphite liberation from the gangue but grades of less than 30% were achieved. Cleaner and recleaner flotation tests on the -180+75 micron size range failed to improve on these initial rougher tests. A small degree of regrinding of the rougher tail, from 180 to 150 micron top size, improved recovery but did not achieve any significant improvement in graphite grade from the rougher tail.
In order to achieve a high grade of product from the samples supplied, a grind size below 75 microns is recommended. The softness and smearing effect of the graphite on the gangue minerals, drives the need to take small size reduction steps followed by multistage flotation. The sample supplied for testing was RC chips and the RC drilling process itself may increase the smearing effect of graphite over the gangue minerals and any further testwork should be carried out on diamond drill core.
The testwork results from this initial study have shown that an upgrade to just over 50% graphite can be achieved in 1-2 stages of flotation. Further test work would be needed to determine if additional grind-flotation and/or gravity stages could increase the grade to produce a high grade graphite product.
Castle is currently seeking end user/industry participation to advance project development