An updated JORC-compliant resource estimate for Gilbert Arc deposit lifted global resource tonnes from 29.6 million tonnes with 5 million tonnes of high-grade material grading 22.5% total graphitic carbon (TGC).
There is now 51% of the resource that will form part of the initial mining area in the measured and indicated categories for 1.67 million tonnes of contained flake graphite.
The measured category comprises 6.5 million tonnes at 12.1% TGC and the indicated category 8.4 million tonnes at 10.5% TGC.
Resource category breakdown of the Gilbert Arc.
Walkabout’s technical director Andrew Cunningham said: “The Gilbert Arc deposit at Lindi Jumbo continues to deliver value for our shareholders.
“Unique, very high-grade domains from surface are one of the factors that makes this deposit the standout project amongst its graphite peers in East Africa.”
The updated resource estimate was calculated by independent geological consultancy, Trepanier Pty Ltd.
Drilling and trenching work
It incorporates results from drilling and trenching over the northern inferred resource area as well as a new mineralised zone south of the Gilberts Arc deposit.
There were 17 drill holes completed for 1,354 metres and seven trenches for 654 metres.
In these trenches, spectacular high-grade mineralisation was encountered at surface with individual metre samples of up to 44% TGC.
The work has seen the northern area of the resource upgraded to the indicated category and this will form part of upcoming mining studies.
A new inferred resource area has been defined directly to the south of the current planned open-pit area.
Mineralised domains at Gilbert Arc and the new southern area.
This area will not form part of the new mining studies, amended definitive feasibility study (DFS) and reserve upgrade as further work within the area will be done post-production.
High-grade domains extended
Domains 7, 8 and 9, which contain the 22.5% grades, have been extended towards the north and remain open.
These high-grade domains form the core of the current mine plan.
The updated resource will be incorporated into the mining studies and an amended DFS, which is expected to be announced in early 2019.
Cunningham added: “We look forward to the upcoming mining studies and amended DFS which will include the extended high-grade zones from surface.”