A day in the life of a mine

Kiirunavaara, under the town of Kiruna in Swedish Lapland, is the world's largest underground iron ore mine. LKAB has mined it since 1898 and takes about 73,000 tonnes of ore out of it on an average day. The 3D view above follows one day there, hour by hour: the nightly blast, the hours of ventilation after it, the loaders, the driverless trains on the 1,365 m level, the skips, the pellet plants and the ore train to Narvik. Every depth and length in it is to scale, and every fact comes from LKAB's own reports or the sources listed at the foot of the page.

The hours of the day

1. 00:00Midnight: the mine never sleeps

   Kiirunavaara keeps working through the night. 1,365 m down, driverless trains shuttle ore to the crushers, and skips run it up the shafts at 60 km/h. On an average day 73,000 tonnes of ore come out of the ground. LKAB, blasting LKAB annual report 2025 LKAB technical report 2023

2. 00:50Clearing the blast areas

   Every night the ore that was drilled and charged during the day is blasted. First the production areas are emptied of people. LKAB gives no exact time for this; we draw it in the half hour before the window. LKAB, blasting

3. 01:2001:20, the blast

   Between 1:15 and 1:45 a.m. the charges go off in the production areas, ring by ring, breaking the ore so the loaders can draw it. Up in town, people sometimes feel it. LKAB, blasting LKAB technical report 2023

4. 02:10Ventilation

   Fans clear the explosive gases for several hours before anyone may go back to the blasted areas. We draw three hours. LKAB, blasting

5. 05:00Back to the drawpoints

   Loaders scoop the broken ore at the drawpoints and tip it down the orepasses. Above each ring the waste rock caves in after the ore: that is sublevel caving, and it is why the ground over the mine sinks. LKAB technical report 2023

6. 07:00Drilling tomorrow's rings

   Remote-controlled rigs drill long holes up through the ore in fans, and the holes are charged for the next night's blast. Elsewhere, crews push about 34 m of new tunnel a day. LKAB annual report 2025 LKAB technical report 2023

7. 09:001,365 m: the driverless railway

   The orepasses empty into rail cars on the main haulage level. The 12 km railway runs without drivers and takes the ore to discharge stations over the crushers. LKAB technical report 2023 Railway Gazette LKAB annual report 2025

8. 11:00Up at 60 km/h

   Crushed to about 10 cm, the ore is hoisted in two lifts: from the 1,465 level to 775, then from 898 to the surface. Each skip carries 40 tonnes; about 1,830 full skips reach daylight on an average day. LKAB annual report 2025 LKAB technical report 2023

9. 13:00Sorting, grinding, firing

   At the surface magnets pick the magnetite out of the waste rock. The ore is ground fine, upgraded and rolled into pellets that are fired in rotary kilns. LKAB technical report 2023

10. 16:40The ore train leaves

    Two Iore locomotives pull 68 cars of pellets, 750 m and 8,600 tonnes, out of the yard. Kiruna's output fills about 5 trains on an average day. Wikipedia, Iore International Mining LKAB technical report 2023

11. 18:00170 km to Narvik

    West over the mountains and the Norwegian border to the ice-free port at Narvik, at up to 60 km/h loaded. The empties come back at 70 km/h. LKAB technical report 2023 Wikipedia, Iron Ore Line Wikipedia, Ofoten Line

12. 21:00Deeper every year

    Underground rigs drill exploration holes below the main level: over 50,000 m in a year. The ore body goes on down to as much as 2,400 m, and the mine is following it. LKAB technical report 2023 LKAB annual report 2025

How the ore moves

1. Drill and chargeRemote-controlled rigs drill long, upward holes through the ore, which are then filled with explosives.
2. Blast at nightIn Kiruna the blasts go off between 1:15 and 1:45 a.m. The production areas are evacuated before blasting can take place.
3. Load and tipLoaders take the ore at the drawpoints and tip it into rock shafts, the orepasses.
4. Down the orepassesGroups of up to four orepasses feed loading galleries on the 1,365 m level.
5. Driverless trainsAn automatic train system on the 1,365 m level carries the ore to central crushing and skip hoisting. The 12 km driverless railway at 1,365 m was inaugurated on 21 May 2013; nine 108 tonne locomotives run on it.
6. Crush to 10 cmThe rail cars are emptied into discharge stations that feed the crushers, which break the ore into pieces about 10 cm across.
7. Hoist in two liftsSkips haul 40 tonnes of ore at a time at 60 km/h. Five internal shafts hoist the ore from the 1,465 level to the 775 level; from there eight shafts lift it from the 898 level to the surface.
8. Sort with magnetsAt the sorting plant the ore is crushed to under 200 mm, screened and passed over magnets that take out the waste rock: around 10 Mt a year.
9. Grind and pelletiseThree concentrating and pelletising plants grind the magnetite, separate it with magnets and roll it into pellets, which are dried and fired on a moving grate and in a rotary kiln, then cooled to about 50°C.
10. Rail to NarvikAll of Kiruna's iron ore products go about 170 km by rail to the ice-free port of Narvik in Norway, on a single line with passing places. An ore train has 68 cars, is 750 m long and weighs 8,600 tonnes, hauled by two Iore locomotives of 5,400 kW each.

An average day in numbers

LKAB reports by the year, so these are a year's totals divided by 365: the real flow changes from hour to hour and day to day. The sum is shown for every figure.

What the drawing shows, and what it doesn't

Depths, the ore body, the tunnels' levels and the trains' lengths are drawn to scale (one unit is 100 m). The surface is today's satellite picture, streamed from Esri. Where buildings, shafts and tunnels sit is approximate: LKAB doesn't publish its mine plans, so the tunnels are a schematic of the method its reports describe, not a survey. Machines are drawn larger than life so they can be seen, and they move at a pace for the eye, except the skips, which always run at their true 60 km/h, and the ore train, which keeps to the clock. Each production area goes through one ring in our day (drilled, charged, blasted, drawn); in the mine those steps don't line up so neatly. LKAB publishes no shift timetable and no train timetable, so we don't draw shift changes, and the five ore trains of our day leave at evenly spaced times. The sun is worked out for Kiruna on the date you pick: from late May to mid July it never sets, and for a few weeks around midwinter it never rises. LKAB technical report 2023 The ground over the mine moves, and the town is moving away from it: that story is The Town.

Questions people ask

What time is the blast in Kiruna?

Every night between 1:15 and 1:45 a.m. LKAB blasts in all the major production areas of the Kiruna mine at night because production never stops: the areas are evacuated first and ventilated for several hours afterwards.

How deep is the Kiruna mine?

The main haulage level is 1,365 m below ground, and the ore body continues to between 1,300 and 2,400 m.

How much iron ore does the Kiruna mine produce a day?

About 73,000 tonnes on an average day, working from the mine's average of 26.7 million tonnes a year in 2014 to 2023.

How long is an ore train from Kiruna?

750 m: 68 cars carrying 100 tonnes each, 8,600 tonnes in all, pulled by two Iore locomotives over the 170 km line to Narvik.

Sources

• LKAB: Blasting
• LKAB Annual and Sustainability Report 2025
• LKAB: Kiruna Mine, Summary Technical Report (PERC), December 2023
• Railway Gazette: Automated railway inaugurated 1 365 m underground (22 May 2013)
• International Mining: World's most powerful locos to increase LKAB's iron ore transport capacity (2 May 2011)
• Wikipedia: Iore (locomotive)
• Wikipedia: Ofoten Line
• Wikipedia: Iron Ore Line
• Wikipedia: Kiruna mine

Surface imagery: Powered by Esri (Esri, Vantor, Earthstar Geographics), streamed live and not stored. Figures are rounded; an average day is worked out from yearly totals. We describe rocks, not stocks: nothing here is a view on any company.

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Cover photos from Wikimedia Commons: Conveyors, rail and ports by Kabelleger / David Gubler, CC BY-SA 4.0. Pictures: Kirunavaara gruva, Kiruna., Fotograf okänd, / Europeana (Public Domain Mark 1.0).