BATTERY AND ELECTRIC MACHINES
Komatsu has formed the Komatsu Greenhouse Gas ( GHG ) Alliance with Rio Tinto , BHP , Codelco and Boliden , looking to – initially – advance Komatsu ’ s power-agnostic truck concept for a haulage vehicle that can run on a variety of power sources including diesel-electric , electric , trolley ( wired ), battery power and hydrogen fuel cells .
Liebherr , too , is accelerating the implementation of its existing low carbon solutions , announcing at MINExpo 2021 in September that it was developing three drivetrain options to achieve near zero emissions for its off-highway trucks : a battery-power module , internal combustion engines powered by renewable fuels and H2 fuel cell-battery power module .
Out of Asia , XCMG has teamed up with Vale to test prototype “ zero emission ” mining haul trucks up to 240 t payload , and SANY and ZOOMLION have launched wide-body batteryelectric trucks .
The likes of Anglo American , Fortescue Metals Group and Antofagasta have also gone on record with haulage projects powered mainly off hydrogen fuel , namely fuel cell electric vehicles .
This is on top of the trolley-assist options that are already being leveraged across industry and are likely to evolve into battery-trolley operation in the future .
The smart way of moving ore
The mine electrification operating philosophy below ground is , arguably , a little clearer , with leading OEMs on course to electrify their full underground loading and haulage fleets in the next decade through mainly battery power . Similar to the way the open-pit sector is evolving , the question now turns to : how do they automate these electric vehicles ?
The trends of automation and electrification overlap when it comes to the digital core both share . This sees telematics , machine monitoring and positioning , and other data pass seamlessly between software platforms . Such integration was displayed back in September 2020 when Sandvik debuted its AutoMine ® Concept vehicle from its Test Mine in Tampere , Finland , and this is also likely to be highlighted when Epiroc launches an automated version of its Scooptram ST14 Battery LHD .
Yet , the major challenge manufacturers are acknowledging is how to automate the batterycharging or swapping methodology that comes with these electric vehicles .
Epiroc is studying many options to automate the battery-charging / swapping process and Franck Boudreault , Electrification Transformation Lead at Epiroc ’ s Underground division , thinks a battery-trolley solution could work well in some applications .
“ Batteries have limited capacity so you cannot expect to run a machine on it all day when carrying out ramp haulage ,” he told IM . “ We are years away from batteries being able to operate over those lengths in such a work cycle .
“ In this respect , being able to connect to a trolley and take your power straight off the grid when you are consuming a lot of energy is a smart way of moving ore .”
The company ’ s work on an all-electric battery trolley truck system based on its MT42 Battery truck with Boliden and ABB at the Kristineberg project in Sweden , plus research under the NEXGEN SIMS project , will lay the foundations for this work .
The rationale for automating this size of battery-trolley truck is strong , as Anders Lindkvist , Technology Development at Epiroc ’ s Underground division , explained .
“ The key to this is the electric drivetrain ; you can combine that battery with trolley or some other energy source ,” he told IM . “ When you have a battery-trolley machine , for instance , you don ’ t need to swap the batteries or plug into the charger ; you charge through the grid when on trolley or through regenerative power when going down-ramp or braking .”
Erik Svedlund , Head of Marketing – Rocvolt Business Development , a part of Epiroc ’ s Underground division , spelt this out : “ In theory , a battery-trolley truck that is running on ramp and is autonomous would have to stop for the first time when requiring grease or changing tyres .” The automated and electrified operating haulage philosophy the Epiroc trio discussed here does not share many – if any – similarities with the earlier Kiruna trolley trucks Epiroc , via GIA Industri , put into operation in Sweden and Canada decades ago , and which are still running at Vale ’ s Coleman and Creighton mines ( see GEVs at Vale section for more information ).
Gone is the AC trolley operation that came with safety hazards when ‘ contacting ’ mine infrastructure , gone are the copper bars bolted to the roof of major areas of the mine , gone is the
Epiroc ’ s MT42 Battery truck ( pictured here on the left with the Scooptram ST14 Battery ) will be used as part of an all-electric battery trolley truck system for Boliden ’ s Kristineberg project in Sweden
need for a diesel generator that limited the truck ’ s performance off-trolley and gone is the lengthy and expensive trolley installation process .
This is on top of the lack of automation this decades-old solution offered .
Instead , the solution Epiroc is putting forward as part of its work with Boliden and ABB is a “ zero emission ” trolley truck with many more applications , as Lindkvist explained .
“ Everything is different on the battery-trolley truck ,” he said . “ A Kiruna truck was a state-ofthe-art concept in the 1980s , but we ’ re doing something completely new .
“ On top of the safety benefits , the installation cost is much less . Instead of a number of copper bars bolted to the roof , you now have two wires operating off DC voltage that trucks connect to . “ The installation time – time when you are blocking the ramp – and cost is much less . It is also much more flexible with the trolley infrastructure only installed on the haulage ramp where the energy needs are the highest .”
Boudreault added to this : “ The MT42 batterytrolley does not need to connect to the trolley going down the ramp – on Kiruna trucks , that was the only way to control the speed downhill otherwise they would start free-wheeling . Because we have a battery on board and , of course , we use gravity to recharge the batteries , it has a lot more flexibility to attach and detach from the trolley .”
This means the trucks will be able to have the same performance on- and off-trolley without any emissions .
In theory – and important to this discussion – they would also be able to continuously operate without an automated battery charging or swapout process .
Boudreault believes such a solution could suit
28 International Mining | FEBRUARY 2022