With its decline more than half-finished, the Storliden project is taking shape as Sweden’s newest copper-zinc mine.
Situated in the Skelleftea district, the project is owned by Swedish-based
Storliden’s potential was first detected during an airborne electromagnetic survey in 1997 and, soon afterwards, confirmed by drilling. A year later, underground resources were pegged at 1.8 million tonnes grading 10.3% zinc and 3.43% copper, plus 0.25 gram gold and 24 grams silver per tonne.
Following standard reviews, the portal was blasted in March after Boliden agreed to become the project’s principal contractor during the construction phase and to operate the mine once it reaches production. Boliden will also process the crushed ore at its mill just outside the town of Skelleftea, 90 km away.
The ramp, which is scheduled for completion in December, will eventually extend for 960 metres to provide access to the 1.8-million-tonne deposit. Commercial production will follow in March, thereafter yielding 25,200 tonnes of zinc-in-concentrate and 11,150 tonnes of copper-in-concentrate annually over six years.
Capital costs are estimated at US$13.9 million, of which US$2.3 million will be used to modify the mill. Boliden is providing the financing and will be repaid out of 75% of the first year’s revenue.
Life-of-mine net profits are projected at US$59 million, two-thirds of which will accrue to NAN and the rest to Boliden. NAN is also entitled to a bonus of US$1 million and intends to recover US$5 million in exploration costs.
All financial estimates assume a copper price of US70 per lb., a zinc price of US40 per lb. and an exchange rate of Kr10.2 per US$1.
A similar deal may be inked for the nearby Norrliden project, pending the outcome of a prefeasibility study. Boliden is focusing on a high-grade core of 775,000 tonnes grading 0.8% copper, 7.8% zinc, 0.7% lead, 1.1 grams gold and 100 grams silver. Total resources stand at 2.9 million tonnes grading 0.7% copper and 2.5% zinc.
NAN owns 90% of Norrliden, with the remainder held by Swedish-based International Gold Exploration. The latter is carried through to the feasibility stage.
Meanwhile, NAN has received a US$1.3-million credit facility from Boliden and South Atlantic to fund ongoing exploration. South Atlantic, in turn, is getting a US$1-million (Kr10-million) line of credit from its chairman, Adolf Lundin. Some will be used for work in the Storliden area, but a portion will be applied to the Koillismaa polymetallic project in Finland, where a small drill program was recently completed.
Situated 40 km west of Kusamo, Koillismaa covers 50 sq. km of an Archean ultramafic layered intrusive complex. The pluton was historically explored for copper and nickel, mostly by
In the 1990s, the Geological Survey of Finland drilled more than 13,000 metres to confirm the intrusion’s potential for low-grade, bulk-tonnage polymetallic mineralization near its base. More recently, NAN has discovered reef-type mineralization higher up in the stratigraphy.
Four holes were drilled — three in the Portivaara block and one in the Syote block. Faulting separates these and three other blocks that form what is known as the Marginal Series.
At Syote, hole 001 intersected sporadic, weak disseminated sulphides from 95.6 to 193.5 metres. The section includes a single, 10-cm-wide band of semi-massive pyrrhotite (and trace chalcopyrite) and coincides with a conductor highlighted by ground electromagnetics.
Assays are still pending.
Results from Portivaara were insignificant, but 10 earlier holes cut variable grades and thicknesses over a strike length of 6 km. The best was hole Musta-7, which cut 18 metres grading 0.25% copper, 0.2% nickel and about half a gram of platinum-palladium-gold per tonne.
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