Boliden has installed four trolley assist truck units at its Aitik copper mine in Sweden as the company looks to step up its vision for fossil fuel-free operations, the company’s Technology Director, Staffan Sandström told attendees at Epiroc’s Power Change Days event in Örebro, Sweden, this week.

The trolley kits, supplied by Caterpillar, are running on Cat 795F haul trucks on a trolley assist line as part of a two-year trial project at Europe’s largest open-pit copper mine.

For the project, Boliden has joined forces with Eitech and ABB to supply electrical infrastructure; Pon Equipment and Caterpillar for truck modifications; and Chalmers University with supporting research on system aspects of the electrification. The project is supported by the Swedish Energy Agency and has seen an investment in a 10 MW capacity DC substation.

The aim is to examine the possibility of replacing elements of Aitik’s transport system with electrified trucks. The objective is to be able to move the majority of the 70 million or so tonnes of rock transported at the open pit each year entirely without the use of fossil fuel.

At the event this week, Sandström confirmed the first trolley line was commissioned in September and had been working well, showing a close to two times increase in speed on an incline when compared with the equivalent diesel trucks.

The real test for the trucks and trolley line was yet to come, he said.

“This is nothing new; it has been done before. The new thing here is going to be working in 40° below [freezing],” he said.

The project’s Technical Manager, Jonas Ranggård, made a similar remark recently in a Boliden press release, saying: “As we want to be able to use the electrified routes in all weather conditions year-round, the pilot project as a whole can only first be evaluated at the end of 2019/start of 2020.”

Rikard Mäki, Project Manager for the R&D project, told IM the company was already preparing for these conditions.

“Road maintenance impact is one of the parameters that will be evaluated in the pilot project in order for us to accurately take this factor into account as part of the following investment decisions. We have fitted one motor grader and a wheel loader with machine guidance systems in order to maintain correct flatness, target slope and height of the ramp.”

On the trolley assist technology, Sandström continued: “Today, it works very well and roughly 30% of all transport has potential to be used on the trolley line at Aitik,” he said, adding it could have wider applications at the company’s Kevitsa nickel-copper mine in Finland.

Boliden said the first Aitik trolley line is around 700 m long and is expected to save some 830 m³/y of diesel. This should help the company reduce its greenhouse gas emissions by up to 80% along those routes where the technology can be implemented.

In addition to the emission benefits brought to both the wider community and those operating in the mine, Sandström said the productivity and cost benefits (reducing the amount of diesel purchased) could also have a big impact.

Mäki said: “We do see this technology as the most promising solution near term for both Kevitsa and Aitik in order to reduce fuel cost and emissions. Decision to move ahead with further extension of the system is pending results from the pilot test. The initial results are looking very positive and the operators are very engaged in the pilot test.”

In other news, but still on haul trucks and potential electrification, Boliden confirmed in its September quarter results that, on October 19, the company reached agreement with Komatsu regarding the purchase of 17 haul trucks for Kevitsa and nine mine trucks for Aitik in an investment totalling some SEK 900 million ($99 million).

The investment is being made against the background of the ongoing expansion, insourcing of transport and as a replacement for part of the existing fleet of trucks. Boliden said all of the trucks are equipped for future electrification and delivery will commence in mid-2019.