Kevitsa Mine

 mine, copper mine, nickel mine/processing

This is the mining concession for the Kevitsa nickel-copper-platinum mine which is owned by First Quantum Minerals Limited through their Swedish subsidiary, Kevitsa Mining AB (KMAB). The land and surface rights are owned by Kevitsa Mining AB’s Finnish subsidiary Kevitsa Mining Oy. Mining started at Kevitsa in June 2012 which is one of the world's major undeveloped sulphide nickel deposits and one of the largest mineral discoveries in Finland's history. The Geological Survey of Finland (the Geologian Tutkimuskeskuksen, or GTK) discovered and drilled the Kevitsa deposit in 1984, with significant mineralization found in 1987.

The Kevitsa Intrusion, which hosts the namesake deposit, is situated within the Baltic Shield. Intrusive activity towards the end of the Archaean generated an abundance of layered intrusions. The intrusion measures some 3.5 km north-south by 5 km east-west, it has a roughly circular outcrop/subcrop and comprises basic olivine pyroxenites and metaperidotites in the northeast, gabbro in the west and central areas and granophyre primarily in the south. It is characterized by internal layering defined by changes in petrologic composition.

The deposit is contained within the olivine-pyroxenite of the ultramafic zone of the Kevitsa Intrusion. The zone contains up to 5% sulphide, the majority of which occurs as granular masses interstitial to the cumulate silicate mineral grains. Mineralogy comprises largely olivine and orthopyroxene. The finely disseminated sulphides are 100-500 mm in size, and consist of pyrrhotite, troilite, chalcopyrite, pentlandite, cubanite, millerite and heazlewoodite. The main ore type forms a zone up to 300m thick in the centre of the deposit. It has a high sulphide content, high nickel and copper grades, significant PGE and gold contents and high Ni/S, Ni/Co and Ni/Cu ratios. The nickel-PGE type has a higher Ni/Co ratio than the main type, and has a tendency towards lower sulphur and copper contents.

Kevitsa mine is designed as a conventional open pit mining operation and the process design consists of conventional: crushing, SAG and ball milling, sequential copper and nickel flotation with thickening and filtration of the copper and zinc concentrates. The life of mine is expected to be ~20-30 years mining at a rate of 7.5 Mtpa.