Silver Mine - History
Discovery of the deposit
The first indications of the Ag-Au-Zn-Pb mineralisation at the Silver Mine site were found in 1980 when a research group from the University of Oulu found several Ag-Au-Zn anomalous glacial boulders along the dry shoreline of the small lake. The University of Oulu exploration team followed up boulder indications by percussion drilling and obtained samples from the bedrock-moraine interface together with small rock chip samples from the bedrock. Results from the percussion drill sampling campaign revealed the sub-cropping mineralisation ca. 500 meters up ice direction from the boulder discovery site.
Kajaani Oy enters the play
In October 1980, Kajaani Oy secured mineral rights over the Silver Mine deposit by claim reservations. In January 1982 two claims were granted. They cover the today known Silver Mine Ag-Au-Zn deposit and its immediate surroundings. A successful fast-track exploration was followed by a diamond drilling campaign during 1981-1989. The surface drill campaign was successful in delineating 40 metres to 100 meters wide mineralisation which has a strike extent of 550 metres and continues to at least 650 metres below the surface.
Taivalhopea joint venture
Kajaani Oy and Outokumpu Oyj made a joint venture agreement in 1988 for the development of the silver deposit and started to build a tunnel down to the mineralisation. 2,6 kilometres long decline and approximately 350 metres long ventilation shaft were mined between 1988 and 1990 which was approximately 60 million SEK investment. After conducting a feasibility study and technical design analyses for mining in 1991, the project was put down due to low metal prices. Silver price at that time was approximately 4 USD per ounce. The price had been between 5 and 10 USD per troy ounce since the project started. Silver prices stabilised at more than 5 USD per troy ounce in 2004, but by then both Kajaani and Outokumpu had changed their focus away from industrial mining.
Sotkamo Silver started the development again
In 2005 earlier owners let the mining concession lapse. The same year the owners of Sotkamo Silver Oy (Silver Resources Oy at that time) applied for a claim reservation over the property. In 2006 Sotkamo Silver applied for the previously presented claims over the Silver Mine deposit and they were issued in May 2007. Since 2006 Sotkamo Silver has developed the mine project until the successful commisioning and start of the production in 2019. It took almost 40 years from the initial discovery to the production.