Kevitsa Nickel and Copper Mine, Lapland

Boliden announced a $92.8m expansion plan for Kevitsa in February 2018 to ramp up production to 9.5Mt per year from 2021. Mining at Kevista is expected to continue until 2033.

Kevitsa mine geology and mineralisation

Kevitsa poly-metallic ore body forms the central part of the Kevitsa igneous complex located within the Central Lapland Greenstone Belt (CLGB). Kevitsa igneous complex is a layered intrusion having a curvy shape at surface and extending to more than 1.5km in depth.

Kevitsa deposit hosts two types of ore including nickel-copper ore and nickel- platinum group element (PGE) ore. The economic mineralisation at Kevitsa mostly occurs as disseminated copper and nickel sulphides.

Kevitsa mine discovery and development

Discovered in 1987, the Kevitsa deposit represents one of the biggest mineral discoveries in the history of Finland. However, no significant exploration work was initiated until First Quantum Minerals received the environmental permit and mining concession for Kevitsa in 2009.

Final investment decision for the mine development was made in September 2009 with basic engineering and construction beginning in 2010. The mine commenced commercial production in August 2012.

Kevitsa mineral reserves

Kevitsa mine was estimated to contain proven reserves of 71.4Mt of ore grading 0.21% nickel, 0.34% copper, 0.10% gold, 0.19% platinum, 0.12% palladium, and 0.010% cobalt, as of December 2017.

The probable reserves were estimated to be 62.4Mt of ore grading 0.24% nickel, 0.34% copper, 0.10% gold, 0.21% platinum, 0.14% palladium and 0.010% cobalt.

Mining at Kevitsa

Kevitsa employs conventional open-pit mining method involving operation drilling, blasting, loading and hauling with the use of hydraulic excavators for ore extraction, and trucks for transportation.

The Kevitsa ore deposit is planned to be mined in four stages. The second phase mining is currently underway with the pit depth being 500m.

Kevitsa produced 29,957t of copper and 13,777t of nickel in concentrates in 2017.

Processing

The run-of-mine (ROM) ore is processed at the nearby 9Mtpa processing facility, where it goes through two-stage crushing, double-deck screening and two-stage milling before undergoing the flotation, thickening and filtering processes for the production of copper and nickel concentrates.

The produced nickel and copper concentrates are further condensed and drained before transporting to Boliden’s own smelting plant in Harjavalta in Western Finland.

Kevitsa mineral processing facility currently houses two 7MW autogenous grinding (AG) mills and a 14MW pebble mil.

Boliden plans to add a new autogenous mill as well as a new mill house at Kevitsa processing facility. It also plans to expand the capacity of its Harjavalta copper-nickel smelter with a total investment of $144.8m by 2021.

Infrastructure and facilities

The power for Kevitsa mining operation is supplied from the nearby Vajukoski hydropower station.

The mine is accessible from Sodankyla, the closest town located 40km south, through all-weather sealed roads.

Fresh water for the mine is sourced from Vajukoski pond, which is located at 7km west.

The other facilities the mine include a waste rock dump near the open-pit and a tailing dam near the processing facility.

Contractors involved with Kevista mine

Pöyry, an international consulting and engineering company based in Finland, was the engineering, procurement, construction and management (EPCM) contractor for the Kevitsa mine development.

Mäcklin Oy was contracted for grade control (GC) and reverse circulation (RC) drilling for the Kevitsa mine in 2011.

Arctic Drilling Corporation (ADC) was contracted for RC drilling in 2013.

Rovamitta Oy was contracted for surveying the collar positions of the drill holes in the mine.

Metso was awarded contracts for the maintenance and wear parts supply of Kevitsa primary gyratory crusher and grinding mills in 2015.