Inspection of the Kiruna mine (KUJ) continues after the major seismic event which occurred on the morning of Monday, May 18th. Production amounting to about 25,000 tonnes per day, a third of the normal rate, has resumed in the so-called lake orebody. Damage to the mine is extensive; however, the area in which the event occurred remains closed, since the full extent of the damage has not yet been determined.
The seismic event occurred at 3.11 a.m. on May 18th. The event had a magnitude 3.3 on the local magnitude scale and occurred at a level of -1,146 metres (from zeroing point) in the mine’s foot-wall. The mine was evacuated and 13 people who were at work under ground left their work sites and returned to surface level. Inspection, which began on Monday, continues.
On Thursday May 23rd targeted production of about 25,000–30,000 tonnes of crude ore per day, or about a third of the normal production volume, resumed in the lake orebody. This volume, together with current stocks of ore and an upcoming maintenance stop in the KA3/KK4 processing plants, means that deliveries to customers are unlikely to be disrupted.
It is as yet difficult to day exactly when production in KUJ can return to normal and LKAB is now considering different alternative for making up the production shortfall.
“We have close contact with our customers, who have expressed relief over the fact that no LKAB personnel were injured. Naturally, there is some concern as to whether deliveries will be affected. We are aware that customers understand the situation and are convinced that we are doing all we can to ensure that production can continue under safe conditions,” says Markus Petäjäniemi, Senior Vice President Market and Technology, LKAB.
Inspection and damage survey of KUJ
In the area where the event occurred there is still a high level of seismic activity and the area remains cordoned off. Rock technicians are now working all out with inspection and damage survey. Access roads to ventilation, power supply, dewatering systems and mine plant and equipment have been opened for repair and reinforcement work. Information to enable future planning is being gathered on an ongoing basis.
“Damage to the Kiruna mine is extensive, but the exact extent is not yet known. Thankfully, no personnel were injured during the event. We can confirm that this was a serious event that will have long-term consequences. We must give careful consideration to how we will manage the increasing rock stresses while at the same time minimizing the risk of personal injury,” says Kiruna mine manager Nils Stenberg.