Alaska-focused mineral explorer Trilogy Metals on Monday reported a maiden 77-million-pound cobalt resource for its Bornite project.
The resource estimate used assay data from drill holes completed by the company between 2011 and 2013 and re-sampled historic holes drilled in the 1960s and 1970s.
“The metallurgical test work completed to date indicates that 80% to 90% of the cobalt reports to the copper tails as cobaltiferous pyrite. This is great because forming a pyrite concentrate from the copper tails should be relatively straightforward using flotation or dense media separation,” CEO Rick Van Nieuwenhuyse said in a statement.
He added that, in the next few months, Trilogy will complete flotation test work to concentrate cobalt into a pyrite-rich product that can be considered for further upgrading and recovery of cobalt metal at the Bornite site.
Owing to Trilogy’s ongoing metallurgical test work, the company has determined that a cobalt product may be produced on site and, therefore, justifies reporting an initial cobalt resource in addition to the already existing copper resource at Bornite.
At a base case 0.50% copper cutoff grade, and within the combined indicated and inferred copper resource pit shell, the Bornite project is estimated to contain in-pit inferred resources of 124.6-million tonnes grading 0.017% cobalt for 45-million pounds of contained cobalt.
Below the resource limiting pit shell and at a base case cutoff grade of 1.5% copper, the Bornite project is estimated to contain additional inferred resources of 57.8-million tonnes grading 0.025% cobalt for 32-million pounds of contained cobalt.
Total inferred resources include 182.4-million tonnes grading 0.019% cobalt for 77-million pounds of contained cobalt.
“With the market interest in finding cobalt resources outside of the Congo – where child labour and worker exploitation have been highlighted by Amnesty International and others as problematic for the automotive and electric battery industries - defining a large, North American cobalt resource has become a priority for the company,” Van Nieuwenhuyse noted.
“We expect to continue to grow both the copper and the cobalt resources with an 8 000 m to 10 000 m drill programme of in-fill and resource expansion drilling about to get under way during the summer field programme in Alaska,” he added.