One of the greatest challenges facing LKAB over the next few years is the development, planning and installation of a new mining system below the current main levels, i.e. at depths of more than 1,250 metres and 1,365 metres respectively. We call this LKAB Mine 5.0.
As the cost of mining ore increases the deeper you go, there needs to be greater cost-effectiveness to enable us to maintain our competitive edge. The two most recent main levels in Kiruna and Malmberget are the deepest vertical mines in LKAB’s history, and the mining methods used to achieve these depths are the most high-tech in the world.
Vertical mining means mining ore at new depths below previous main levels, because the mineral resources above have been exhausted. LKAB has throughout its history gradually increased the depth of mining, establishing new main levels at between 50 and 295 metres each time. Each new main level is then equipped with new systems for chutes, transport, crushing and hoisting. The method of mining ore at ever-increasing depths is known as vertical mining.
The next generation of mining systems takes vertical mining to literally a whole new level, and to maintain or increase the competitiveness of the operation ore has to be mined on an even larger scale. This can be achieved with new technology for drilling and charging. Efficient mining methods, automation and transport using driverless vehicles, 24-hour mining operations and real-time production management are important areas of development to be able to deliver competitive ore mining.
Increasing the depth of mining brings its own challenges. The word ‘seismic’ comes originally from Greek and means ‘shaking’. Mining has an impact on the tension present in the rock. When the tension is redistributed, vibrations develop. This is called seismic activity and it is recorded by LKAB’s seismic systems.
The mine of the future will employ technology, such as effective rock reinforcement and monitoring of the rock’s seismic activity in real time, to increase mine safety.
LKAB has devised a system for rock reinforcement where all drifts are sprayed with a layer of fibre-reinforced concrete. Holes are then drilled for three-metre-long steel bolts. Finally, a protective mesh is applied and secured in place using large washers and steel bolts inserted into the rock. This system has been shown to make working underground considerably safer.
Mining at greater depths
Ore is extracted from LKAB’s underground mines by means of large-scale sub-level caving. Since 2008 new methods have been developed for dynamic rock reinforcement, and major new systems for recording and analysing seismic activity have been installed. Safety is LKAB’s number one priority.
Mine 5.0 is our way of tackling issues related to mining below the current main levels, including ore crushing, mucking, transport and hoisting. LKAB will in all likelihood have to increase production and yields, while keeping costs down, in order to be able to continue mining ore at even greater depths.