A year’s worth of high-performance bolts for one of the largest underground Iron mines in the world
LKAB is one of the largest underground Iron mines in the world and the largest in Europe. LKAB operations are situated in Norrbotten County, north of Sweden. LKAB has two underground mines: Kiirunavaara mine in the city of Kiruna and Malmberget mine next to the town of Gällivare.
The mines have different ground conditions and rock formations and are both exposed to dynamic events. The geology of the Kiruna mine consists of several Karelian and Svecofennian metavolcanics and metasediments. Originally the rocks might have been basalt, trachyandesite, rhyodacite, and rhyolite that were altered by metasomatism. The rock formations are extremely compact and hard, with a lot of accumulated stress causing issues with rock bursts.
The ores of Malmberget mine are in Precambrian volcanic rocks, that have metamorphosed mainly to gneisses over time. Containing apatite-bearing iron ore, the entire deposit complex has strongly folded and now consists of several ore sheets that may have originally been connected. Rock formation of this type is highly deformable under stress and causes large convergences.
Due to challenging geological conditions present in both mines and the high demand for safety and productivity, LKAB was looking for rock bolts with high static and dynamic capacity. LKAB required bolts with high impact resistance to cope with rock burst, yet strong and ductile enough to absorb and suspend energy in the swelling and yielding ground.
Normet had supplied the D-Bolt® for special applications in individual projects within the LKAB development for several years.
The D-Bolt® was used in the KUJ 1365 Project at the Kiirunavaara mine’s development of a new production level and during the repairs of roof falls in Malmberget mine, with the setting performance second to none in both projects.
The D-bolt® had an excellent reputation as a dynamic bolt within LKAB operations. After other suppliers failed to supply bolts with high-performance parameters, Normet was invited by LKAB to participate in the tender for the full LKAB bolting needs in 2019.
Normet presented LKAB with an unbeatable offer of superb bolt performance and reliable supply. Normet’s local manufacturing production facility in Lulea provided the “Steel Back to the Mine” concept with local support and exceptional service.