The Zinkgruvan zinc and copper mine is located approximately 250 km southwest of Stockholm in south-central Sweden. The mine site is some 15 km from the town of Askersund and comprises a deep underground mine, a processing plant and associated infrastructure and tailings disposal facilities. Concentrates are trucked from the mine to a nearby inland port from where they are shipped via canal and sea to European smelter customers.
The mining operations are contained within two exploitation concessions; The "Zinkgruvan Concession", and the neighboring "Klara Concession covering the deposit and the immediate area.
Zinkgruvan has good local road access and is close to the main E18 highway linking Stockholm and Oslo. Rail and air links are available at the town of Örebro some 60 km distant. Lake Vänern, the largest lake in Sweden, is 100 km distant and provides access to coastal shipping via a series of inland canals and the port of Göteborg.
The Zinkgruvan orebodies are dominated by sphalerite and galena and are generally massive, well banded and stratiform. Remobilization of galena and silver has occurred in response to metamorphism and deformation, and is most pronounced in the lead-rich western extension of Nygruvan and in the Burkland area.
Copper stockwork mineralization has been identified in the structural hanging wall of the Burkland deposit. Chalcopyrite is the main copper mineral and occurs as coarse disseminations and patches within a marble host rock.
Zinkgruvan is an underground mine with a long history. Mine access is currently via three shafts, with the principal P2 shaft providing hoisting and man access to the 800 m and 850 m levels with the shaft bottom at 900 m. A ramp connecting the underground workings with surface was completed in 2010 and now provides vehicle access direct to the mine. A system of ramps is employed to exploit resources below the shaft and the deepest mine level is now at 1,130 m below surface. The mine is highly mechanized and uses longhole primary secondary panel stoping in the Burkland area of the mine, sublevel benching in the Nygruvan area and in the Cecilia area. Recently underhand panel stoping has been introduced to the lower sections of the Burkland and Nygruvan orebodies. All stopes are backfilled with either paste tailings and cement or waste rock.
The processing plant is located adjacent to the P2 shaft. The run-of-mine ore is secondary crushed and then ground in an AG and ball mill circuit. A bulk flotation concentrate is produced initially before further flotation to separate zinc and lead concentrates. The concentrates are thickened and filtered and then stockpiled under cover. Tailings are pumped some 4 km to a dedicated tailings impoundment from which decant water is returned to the process.
A separate 0.3 mtpa copper treatment line in the processing plant was commissioned during 2010. This line was further modified during 2011 to allow it the flexibility to treat zinc-lead ore as well as copper ore.
The Qualified Persons in respect of Lundin Mining's 2015 Mineral Reserve and Mineral Resource estimates for Zinkgruvan were Graham Greenway, Group Resource Geologist, and David Allison, Group Mining Engineer, both employees of Lundin Mining.
Please see Annual Information Form
, Financial Statements
, Technical Report
and Reserves & Resources
for further information.