Aitolampi – Graphite
The Pitkäjärvi and Aitolampi graphite prospects were discovered by Beowulf in 2016 and are eastern extensions to the Haapamäki prospect, which contains old workings from when graphite prospecting was undertaken many years ago.
They are in eastern Finland, approximately 40km southwest of the well-established mining town of Outokumpu.
Infrastructure in the area is excellent, with good road access and the availability of high voltage power. Beowulf’s 100% owned subsidiary Company, Fennoscandian, holds an Exploration Permit, Pitkäjärvi 1, which covers 999.7ha.
Aitolampi has a global Indicated and Inferred Mineral Resource of 19.3 million tonnes at 4.5% Total Graphite Carbon for 878,000 tonnes of contained graphite, carried out by CSA Global PTY Ltd.
Graphite schists occur on a fold limb that are coincidental with an extensive electro-magnetic (“EM”) anomaly defined by an airborne survey undertaken by Geological Survey of Finland (“GTK”).
Several historic graphite workings correspond to the EM anomaly. As graphite is a good conductor of electricity, EM geophysical techniques are a highly effective exploration tool to define conductive zones (anomalies) that may indicate the presence of graphite. Hence, Beowulf carried out its own additional geophysical surveys in March 2016, utilising Slingram horizontal loop electromagnetic (“HLEM”) geophysical methods, to provide a rapid and initial assessment of the project for potential sub-surface graphite mineralisation. The results of the survey were very encouraging with 46 conductive bodies defined on 28 profiles, the strongest occurring with widths of up to 68 metres.
Beowulf’s geologists subsequently carried out reconnaissance geological mapping and sampling to investigate the conductive zones in the field. Although many of the EM anomalies are obscured by glacial till, it was still possible to determine, at several locations (including road cuttings and old quarries), that areas of graphite mineralisation occur at or close to the EM conductive zones. Two areas of interest, the Pitkäjärvi and Aitolampi graphite prospects, were discovered in 2016. Metallurgical test-work carried out on composited grab samples from both prospects by SGS in Canada produced concentrate grades of 94.5% Total Carbon (“Ct”) and 94.7% Ct, respectively.
Aitolampi was considered by Beowulf’s geologists to be the most prospective for follow-up exploration by drilling. In 2017 and 2018, a total of 2,770.7m was drilled, comprising of 18 diamond drill holes. The drilling confirmed a mineralised strike length of at least 350m along the main EM zone, which extends for 700m. For the two parallel higher-grade zones, mineralisation has a strike length of at least 150m, which extends for 350m and 250m. Mineralisation for all zones remains open along strike and at depth.
Significant mineralised drill intercepts included:
- Drill hole AITDD17006, 202.98m at 3.09% Total Graphite Carbon (“TGC”) from 19.2m depth (this includes some barren zones with no assays and calculated as zero per cent TGC), and higher-grade zones of 18.95m at 6.33% TGC, and 14m at 6.26% TGC
- Drill hole AITDD17001, 141.86m at 3.72% TGC from 19.67m depth, including a higher-grade zone of 39.48m at 5.02% TGC
- Drill hole AITDD17008, 60.29m at 4.01% TGC from 8.71m depth, including 12m at 5.79% TGC
- Drill hole AITDD17005, 41.1m at 4.39% TGC from start of hole, including 28.4m at 5.1% TGC and 4m at 7.71% TGC
Beowulf has determined a JORC compliant resource at Aitolampi of 19.3 million tonnes at 4.5% TGC for 878,000 tonnes of contained graphite, reported from an eastern and western lenses interpreted above a nominal 3% TGC cut-off grade. The Mineral Resource was estimated by CSA Global PTY Ltd of Australia.
The western zone is higher grade with a reported Indicated and Inferred Mineral Resource of 9.8 million tonnes (Mt) at 5% TGC for 490,000 tonnes of contained graphite. The Eastern Zone has an Indicated and Inferred Mineral Resource of 9.5 Mt at 4.1% TGC for 388,000 tonnes of contained graphite.
Based on a grade-tonnage curve above a 4% TGC cut-off grade, the Indicated and Inferred Mineral Resource at Aitolampi reports at 12.8 Mt at 5% TGC for 639,000 tonnes.
The results of the MRE for Aitolampi are shown in the table below:
Table 1 Mineral Resource estimate for Aitolampi as at 20 June 2018
|Zone||Classification||Million Tonnes||TGC%||S%||Contained Graphite ('000s t)|
|Indicated + Inferred||9.8||5||5.1||490|
|Indicated + Inferred||9.5||4.1||4.5||388|
|Indicated + Inferred||19.3||4.5||4.8||878|
Three samples, MET-17001, MET-17002 and MET-17003, comprising composited quarter drill core of approximately 10kg each, were dispatched to SGS Minerals Services in Canada for metallurgical test-work. The objective of the test-work was to develop a preliminary understanding of the metallurgical response of the different samples and to characterise graphite concentrate produced, in terms of flake size distribution and total carbon grades of different size fractions. The results of the test-work are as follows:
- Superior metallurgical response from all three samples compared with grab samples from outcrops analysed previously
- The process flowsheet used was simple, yet proved to be very efficient
- The combined grades ranged from 96.8% to 97.5% Ct across the three samples
- All three samples responded similarly in terms of concentrate grades of the various size fractions
- The -400 mesh size fractions also produced high grades ranging from 95.0% to 97.8% per cent Ct
|Flake Size||Size in Microns||Size in Mesh||% Mass Distribution|
|Large||180 to 300||80 to 50||17||12.2||13.4|
|Medium||150 to 180||150 to 80||30||26.8||29.2|
|Fine||< 106||< 150||51.4||60.4||56.8|
|Ct Combined Concentrate||96.8%||97.20%||97.50%|
|% Open Circuit Graphite Recovery||87.30%||77.80%||91.40%|
Beowulf is currently carrying out characterisation tests on the concentrates to determine potential industrial applications of the graphite.