The earthquake on May 18, 2020 was measured at 4.2 on the local scale, which is by far the largest earthquake caused by mining in Kiruna.
No one was injured, which was largely due to the fact that the incident occurred early in the morning, when few people were underground.
After that, LKAB has been forced to reduce production marginally, but the big question has been how the continued mining will take place.
Safety first
Now the decision has been made.
LKAB leaves a pillar in the middle of the mine where the quake took place.
It is considered to be the safest solution to prevent similar earthquakes from occurring again.
- We don't risk triggering an outcome like we had in 2020, says Joel Kangas, mining manager at LKAB.
Ore for enormous values in the rock
But the decision is also costly.
The pillar that is left contains about 90 million tons of ore.
In total, there is 850 million ore above today's main level.
The value of the ore lost will of course depend on the price of the ore, but it is huge in terms of sales value.
This means that the life of the main level is shortened by three years and is estimated to be mined out in 2040. At the same time, LKAB hopes for future mining at even greater depths.