Volvo Trucks and mining company Boliden are joining forces to implement electric truck transport in underground environments. The Swedish mining group Boliden is becoming one of the first in the world to start using battery-electric trucks for heavy underground transport starting 2023. In mining environments, the electric trucks can deliver several big advantages—including no exhaust emissions, a safer workplace, and quieter working conditions.

Volvo Trucks and Boliden are collaborating on the use of electric trucks in underground mining (image does not show the Kankberg mine).

The mining industry is today going through a period of rapid change, with many players shifting to more sustainable production methods to provide metals with a lower climate footprint. Just like in many other mines, exhaust gases from diesel vehicles are responsible for the majority of the carbon dioxide emissions from Boliden’s mines. The company is committed to reducing its CO₂ emissions by 40% by 2030, and for Boliden to achieve its climate goals, electrification of transport will play a critical role.

The new cooperation agreement between Boliden and Volvo Trucks means that two heavy, electric Volvo trucks will be used in Boliden’s Kankberg mine, outside Skellefteå in northern Sweden. If all trucks in the mine were to be electric, the CO₂ emissions from the mine could be reduced by more than 25%.

This is an exciting collaboration in an environment with very tough demands; steep slopes, heavy loads and humid air that wears on the vehicles. The collaboration with Boliden will give us valuable knowledge about the performance of electric trucks when driven underground, and provide answers to questions about how the driveline and batteries are affected. Reduced carbon dioxide emissions for mining transport also means that we, indirectly, will reduce our own CO₂ emissions, because the mining industry’s raw materials are used in our trucks.

—Jessica Lindholm, project manager at Volvo Trucks

The first truck to serve the Kankberg mine, a Volvo FH Electric, will be used to transport rock bolts and other equipment down into the mine and will be put into service in 2023. Based on the experience with the first truck, another Volvo FH Electric will later be put into operation and used for underground transport of rock and ore.

We see the collaboration with Volvo as a fantastic opportunity to push the electric technology forward and at the same time learn how to adapt our operations for a transition to fossil-free underground transport. A major benefit of the trucks is that they will contribute to a more sustainable mine, both in terms of emissions and also the working environment for our employees. In addition, the total amount of energy consumed in the mine will be lower as electric drive is more energy efficient than a diesel engine, and it is possible to capture the electricity regenerated during engine braking on downhill slopes.

—Dennis Forslund, project manager at Boliden

The Kankberg mine is one of three operating mines—Renström, Kristineberg and Kankberg—in the Boliden area in the mineral-rich Skellefteå field in Västerbotten in northern Sweden. Kankberg produces mainly gold, silver and tellurium.

In 2021 (01 January to 28 December) Kankberg mined 468 kt of ore, with an average grade of 3.41 g/t Au, 9.9 g/t Ag and 156 g/t Te. The mine has produced continuously since 2012 through underground methods, between depths of -530 m and -320 m level, via a ramp-drive system from the historic Kankberg open pit mine to the north.

Mining at Kankberg uses a cut-and-fill process that can also be described as room-and-pillar with fill. The ore is mined in 6 m high horizontal rooms or stopes (7 m if it is a bottom room). The rooms are stacked vertically in 4 to 6 levels, which are accessed from a ramp. The mining starts from a bottom undercut and advances upwards. The mining cycle consists of drilling of the ore, loading of blast holes, blasting, loading of the ore, cleaning of the exposed rock and reinforcing with cemented iron rods and shotcrete.

Once the stope is mined, media such as water, power supply and ventilation are retreated, as the stope is backfilled with waste material. The fill material serves both as support for the stope walls and as working platform for the next stope. Pillars on successive levels are vertically aligned. Ground support is through rock bolting and shotcreting with fiber-reinforced concrete.

The ore is delivered by truck to the Boliden Area Operations Processing Plant (BAOPP), about 10 km from the mine.