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.
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, eight diamond drill holes for 1,197m were completed to test 350m along the main EM conductive zone, which extends for 700m, and along two parallel conductive zones. The drilling confirmed the EM zones identified at Aitolampi are associated with wide zones of graphite mineralisation, with a mineralised strike length of at least 350m along the main conductive zone drill-tested, dipping between 40 and 50 degrees to the southwest.
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
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.