Swedish mining group Boliden is to invest €44m in its Tara zinc mine in Co Meath - Europe's biggest - having found additional reserves that will boost the lifespan of the operation by at least six years.
The new find - called Tara Deep - will also make Tara one of the world's deepest mines, with fresh ore located up to 1.9km below the surface.
Industry insiders reckon the mine, the eighth-largest zinc mine in the world, could still be producing ore in 20 years' time. That would give it a lifespan of at least 60 years. Tara, which opened in 1977, accounts for half of Boliden's total zinc concentrate output and employs about 700 people.
Boliden chief executive Lennart Evrell confirmed yesterday that the expansion of the mine will proceed, pending the receipt of necessary planning permits. He said the expansion was a "very exciting development" for Boliden.
The president of Boliden Mines, Mikael Staffas, told investors yesterday that the group is hopeful that more reserves will be found, given that the company has not even finished exploring around the new find.
The planning application to extend the capacity of the mine's so-called tailings dam - used to store mining byproducts after ore is separated from the material in which it's embedded - has been approved by Meath County Council but appealed to An Bord Pleanála by a number of locals. A decision from the planning watchdog is due by April. The extension to that dam will extend over 58 hectares and provide storage capacity for about 9.6m cubic metres of mine tailings.
Boliden hopes to commence work on that project this year and complete it by 2019. The current dam capacity limits the life of the mine to 2020. The extension will enable production until 2026.
Mr Staffas said that after that, it's not clear how the company could provide additional tailings capacity. That could limit the mine's life, despite having significant reserves, if an additional tailings dam or extension is not in place after 2026.
Boliden will spend an additional €11m on a new tunnel, or drift, to the fresh zinc and lead reserves it intends to mine. Those reserves, about 2km from the existing mine, include 10 million tonnes of ore, at what Boliden said were high grades.