The Pyhäsalmi mine is an underground copper and zinc mine located in central Finland. Pyhäsalmi Mine Oy is a 100% owned subsidiary.
Pyhäsalmi is one of the oldest and deepest underground mines in Europe and produces copper, zinc and pyrite. In 1962 it was initially developed as an open pit mine by Outokumpu Oyj, followed by the first underground development.
Outokumpu designed an underground development plan and in 2001 completed construction of a 1,450-metre deep automated hoisting shaft. Outokumpu started development from the new shaft in July 2001, and in March 2002 Inmet Mining completed the acquisition of Pyhäsalmi and continued the underground development plan.
Pyhäsalmi uses non-entry, bulk open-stope mining methods in a primary-secondary sequence. On average, stope size varies from 50,000 tonnes for narrow primary stopes to over 100,000 tonnes for wider secondary stopes.
Milling includes crushing, 3-stage grinding, conventional flotation using three separate circuits, and water removal to produce copper, zinc and pyrite concentrates.
Production in 2014 is expected to be between 14,000 and 15,000 tonnes of copper and 21,000 and 23,000 tonnes of zinc. Pyrite production is expected to be approximately 860,000 tonnes, in line with the previous year.