Kiruna mine

The Kiruna mine exploits one of the world's largest and richest iron ore deposits, known as the Kiruna-type or apatite-iron ore, hosted in volcanic rocks of the Proterozoic age. The ore body is a massive magnetite (Fe3O4) and hematite (Fe2O3) deposit, extending over 4 kilometers in length and up to 80 meters in width, dipping at about 50–60 degrees. It is part of the larger Malmberget–Kiruna ore field, which also includes other deposits like Malmberget and Svappavaara. The ore is exceptionally high-grade, with an iron content of around 60–70%, and contains minor amounts of phosphorus and vanadium, which are extracted as by-products. The deposit formed approximately 1.9 billion years ago through a combination of volcanic and hydrothermal processes, though the exact genesis remains debated among geologists.

The Kiruna mine employs the sublevel caving method, a highly mechanized and efficient underground mining technique that involves drilling and blasting ore in a series of horizontal tunnels, allowing the overlying rock to cave into the void. This method, pioneered at Kiruna in the 1950s, has been refined over decades and now uses automated, remote-controlled equipment, including loaders and drill rigs, to enhance safety and productivity. The mine operates at depths down to 1,365 meters, with plans to extend to 2,000 meters, and produces approximately 27 million tonnes of crude ore annually. The ore is crushed underground and transported to the surface via a system of conveyor belts and skips, then processed into iron ore pellets and fines for shipment. LKAB, the operator, is a world leader in pellet production, and the mine also produces apatite concentrate for phosphorus and vanadium recovery.

The Kiruna mine has had a profound impact on the environment and local community, leading to significant subsidence and ground deformation that threaten the town of Kiruna. To mitigate this, LKAB and the municipality initiated a historic urban relocation project, moving the town center about 3 kilometers east to a new location, with the relocation of key buildings such as the Kiruna Church, which was moved in 2021. The mine is also a major source of employment, directly and indirectly supporting thousands of jobs in a region with a small population. Environmentally, LKAB has invested in reducing carbon emissions, aiming for a fossil-free steel production process by 2045, and manages tailings and waste rock to minimize ecological damage. The mine's operations have also led to the displacement of the indigenous Sámi people and their reindeer herding activities, a contentious issue that has drawn international attention.

Beyond its scale, the Kiruna mine has several lesser-known facets. It is home to the world's largest underground mine tour, attracting thousands of visitors annually, and features an underground research laboratory for mining technology development. The mine also hosts a unique underground church and a concert hall, used for events and ceremonies. In 2019, the mine was the site of a major earthquake, measuring 4.9 on the Richter scale, caused by mining-induced stress, which led to a temporary shutdown and increased safety measures. The mine's waste rock has been used to create artificial ski slopes and other recreational facilities. Additionally, the mine has been a testbed for autonomous mining vehicles and digitalization, with LKAB partnering with tech companies to develop 'smart mines'. The town's relocation has also unearthed archaeological finds, including ancient Sámi settlements, which have been preserved and studied.

Sublevel caving

An underground mining method where ore is blasted in horizontal tunnels, and the overlying rock caves in to fill the void.

Magnetite

An iron oxide mineral (Fe3O4) that is a major source of iron ore.

Apatite

A phosphate mineral often associated with Kiruna-type iron ores, used for phosphorus production.

LKAB

Luossavaara-Kiirunavaara AB, the Swedish state-owned mining company that operates the Kiruna mine.