Kongsberg Silver Mines
The silver mines of Kongsberg, in Buskerud county in Norway, constitute the largest mining field in Norway, with over 80 different mines. It was the largest pre-industrial working place in Norway, with over 4,000 workers at its peak in the 1770s and supplied over 10% of the gross national product of the Danish–Norwegian union during its 335-year-long history: over 450,000 man-years were expended in the production.
Boliden AB
Business Area Mines conducts exploration, mining and milling operations in Sweden and Ireland. Its main products are zinc and copper concentrate, with some lead, gold and silver content. The goods produced are sold both to the Group's own smelters and to external customers. Boliden owns and operates Europe's biggest zinc mine at Tara in Ireland. Tara became part of Boliden in early 2004, but production began there in 1977, since when over 60 million tonnes of ore have been mined. Boliden also owns Garpenberg, which is Sweden's oldest mine still in operation. Mining at Garpenberg began back in the 13th century. The mineral-rich Skellefte field lies within the Boliden Area, where almost 30 mines have been opened since production began in the 1920s and where Boliden currently operates the Renström and Kristineberg underground mines and the Maurliden open pit mine. Boliden also owns and operates the Aitik open pit mine, which is one of Europe's biggest copper mines. Metal grades at Aitik are low, but this is compensated for by high productivity levels and efficient milling processes that also exploit the ore's gold and silver content. An expansion project that will double Aitik's ore production to 36 million tonnes per annum by 2014 began in 2007 and will be completed in 2010.