Tag Archives: trolley assist

Boliden backs trolley assist haulage for Aitik and Kevitsa

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.

RNC Minerals studying trolley assist, automation at Dumont nickel-cobalt project

The latest feasibility study on RNC Minerals’ jointly-owned Dumont nickel-cobalt asset in Quebec, Canada, has identified the potential for both electrification and automation of the open-pit haulage fleet at the project.

The DFS, completed by Ausenco, showed that initial nickel production at Dumont could come in at 33,000 t/y, before ramping up to 50,000 t/y in a phase two expansion. This would result in some 1.2 Mt of nickel in concentrate output over the 30-year life, with an initial capital expenditure estimate of $1 billion.

This initial investment would be paid back with a $920 million after-tax net present value (NPV, 8% discount) and 15.4% post-tax internal rate of return, factoring in a nickel price of $7.75/Ib (>$17,000/t) and a US$/C$ exchange rate of 0.75, the company said.

Dumont, as envisaged in the DFS, would use conventional drilling and blasting, with loading by a combination of hydraulic excavators and electric rope shovels into trucks ranging in size from 45 t to 290 t. The process plant will be constructed in two phases. Phase one will have an initial average throughput of 52,500 t/d using a single SAG mill and two ball mills for grinding, desliming using cyclones, conventional flotation and magnetic separation, to produce a nickel concentrate also containing cobalt and PGEs. Phase two throughput will be doubled to 105,000 t/d in year seven by mirroring the first line.

Around 42 Mt of overburden will be pre-stripped prior to start-up of operations. The life-of-mine plan excavates 2,100 Mt of material, including 1,000 Mt of ore, over an open-pit life of 24 years. After open-pit operations cease in year 24, 398 Mt of stockpiled ore will remain to support continued production through year 30.

One of the noticeable changes to the previous feasibility study from 2013 was the electrification of the fleet in the mine plan.

The company, which jointly owns Dumont with Arpent Inc, currently plans to increase the electrification of Dumont by incorporating trolley assist on the planned main ramps. RNC said this will reduce cycle times, and reduce diesel consumption by over 35% (approximate reduction of 450 million litres over the life of mine), which, in turn, will cut greenhouse gas emissions by 1.2 Mt of CO2 equivalent, the company said.

And, among three “additional upside opportunities” listed in the DFS highlights was the use of haulage automation, which could potentially improve the NPV by some $75-115 million, the company estimated.

RNC said: “As autonomous equipment has been employed in open pits for over a decade and the global fleet currently approximates a combined 400 units of haul trucks and blasthole drills, automation is rapidly becoming proven technology.”

As a result, the company engaged an industry expert, Peck Tech Consulting, to assess the suitability of Dumont for automation.

“Based on Peck Tech’s prefeasibility-level assessment, the implementation of an Autonomous Haulage System could reduce the peak truck fleet by 20% and reduce site-wide all-in sustaining costs by over 3%,” RNC said.

“Further potential could be achieved with an Autonomous Drilling System (ADS),” the company added, saying it is continuing discussions with various mining equipment suppliers to understand the impacts and benefits in greater detail.

Trolley assist up and running at Boliden’s Aitik copper mine

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.