Boliden has decided to invest SEK300 million ($31.2 million) to expand the trolley assist facilities at its Aitik copper mine, in Sweden, as well as implement the corresponding technology at its Kevitsa nickel mine, in Finland.

The investments, to be made mainly during 2020-2021, come on top of the money invested in a two-year trolley assist pilot project at Aitik. This project saw Eitech and ABB supply electrical infrastructure; Pon Equipment and Caterpillar carry out truck modifications; and Chalmers University provide supporting research on system aspects of the electrification. It led to a 700 m electric trolley line being installed and four Cat 795F haul trucks being converted.

The project was also supported by the Swedish Energy Agency and saw investment in a 10 MW capacity DC substation.

Aitik is currently the only mine in the arctic where electric trolley has been installed, according to Boliden.

Mikael Staffas, President and CEO of the Boliden Group, said: “We are now taking further steps to improve both productivity and climate impact at our two open-pit mines.”

In Aitik, a further 3 km of electric trolley line will be built and another 10 trucks will be converted for electric trolley lines. Overall, the plan means that greenhouse gas emissions from transportation over the life of mine are reduced by nearly 15%.

In Kevitsa, 13 mining trucks will be converted for electric trolley lines at the same time as the 1.8-km-long electric trolley line is being built. The investment means that greenhouse gas emissions over the life of mine are reduced by 9%.

The electric trolley installations are being deployed in stages until 2022.

Boliden calculates that this move will reduce diesel consumption by 5,500 cu.m/y when the investment is completed.

In addition, productivity gains are expected as the electrically powered trucks can run at a higher speed than the diesel equivalents.

The working environment for the drivers is also improved, not least through lower noise levels, Boliden added.