Copper and gold concentrates are supplied to the Rönnskär smelter, while zinc concentrate is shipped to Boliden’s own smelters at Odda in Norway and Kokkola in Finland as well as to other European smelters.
In addition to mine-site exploration, extensive field exploration is also conducted in the Boliden Area. There are about 500 employees in the Boliden Area operations today.
Kristineberg
Kristineberg is one of the deepest mines in Sweden, with operations on levels between 900-1,300 m. The mine came into operation in 1940 and is the oldest mine operating in the Boliden Area. The mine consists of polymetallic ore containing zinc, copper, lead, gold and silver, as well as gold/copper ore. Around 80% of the ore mined at Kristineberg is extracted using the cut-and-fill method.
The mined out sections are mostly backfilled with waste rock and tailings sand from the concentrator. In wider sections, cement is added to stabilise the sand. Successful exploration programmes have discovered new mineralisations at depths of 800 – 1,300 m about 500 m north of the ores currently mined. In 2011, the Kristineberg mine produced a total of 600,000 tonnes of ore. The mine employs approximately 190 people and around 40 contractors, making Boliden the largest private employer in Lycksele municipality.
Renström
The Renström mine, which started operations in 1952, is currently Sweden's deepest mine with a deep ramp at the 1,330 m level. The mined ore is polymetallic with zinc, copper, lead, gold and silver. The ore is extracted using overhand cut-and-fill mining, with waste rock from the extensive development work and tailings sand from the concentrator in Boliden utilised as fill. Exploration programmes show interesting results at Renström, with mineralisations extending from as deep as 1,700 m and upwards to between 800 and 600 m in the Simon area. Renström produced over 275,000 tonnes of ore in 2011 and employs approximately 100 people.
Maurliden
Maurliden started production in 2000. Maurliden's polymetallic ore is extracted in an open pit mine which has been expanded at intervals. A new push-back began in 2008. The final depth of the open pit is planned to be approximately 180 m. All production at Maurliden is sub-contracted.
Maurliden Östra
The expansion of the Maurliden Östra copper-zinc deposit, 2 km from Maurliden, started in the autumn 2009 and all production is in the form of open pit mining. The mine's maximum depth will be approximately 65 m. Operations at Maurliden Östra are coordinated with the work at Maurliden and is sub-contracted.
Figures from 2011