UNDERGROUND LOAD & HAUL
maintenance and repair costs , while minimising emissions . Its redesigned lift arm offers greater lift height which togther with new components delivers up to a 39 % improved lift breakout force over the R2900G , making this model up to 31 t per litre more fuel efficient . Overall , Cat says the machine delivers a 20 % increase in productivity over the predecessor machine . The R2900 XE has an 18.5 t payload making it a good match for the 63 t payload AD63 Cat underground truck . It also has a redesigned bucket for faster cycle time . The new diesel-electric hybrid powertrain combines a Cat C15 engine with EU Stage V option with a Cat switched reluctance electric drive system .
Caterpillar ’ s relationship with Codelco in Chile continues to strengthen with the OEM , through its Finning dealer , awarded an order in 2021 which is now being fulfilled to provide 27 Caterpillar R3000H underground loaders to the Chuquicamata Underground mine . The 20 t class R3000H was launched in 2012 and remains Cat ’ s largest model . It replaced the R2900 XTRA , providing added value for hard rock mine operators with a significant increase in truck loading capacity , being able to three pass load 60 t class trucks , and having enhanced digging and breakout performance , faster speeds on grade , a strengthened front frame , and an available Ventilation Reduction Package . Since then there have been a number of deployments of the LHD but there are only a few underground mines in the world with a potential requirement for large numbers of loaders of this class at one operation . One of these is Codelco ’ s new Chuquicamata Underground blockcave copper mine . This is one of the largest single large LHD orders ever made and will help the mine achieve its intended production rate of 140,000 t / d which is a rate on a par with sister operation and the world ’ s largest existing underground copper mine , El Teniente . Chuqui Underground includes four levels of production ; a 7.5 km main access tunnel , five clean air injection ramps and two air extraction shafts . It will produce 366,000 t of fine copper and more than 18,000 t of fine molybdenum per year & extending Chuqui ’ s minelife to 2060 .
Komatsu brings latest LHD range to Australia
Komatsu Australia in November 2021 said it had , for the first time , entered the hard-rock underground mining market with a concerted solution made up of two larger hybrid LHDs and two diesel-powered narrow-vein loaders . Two high-tech hybrid drive underground loaders , equipped with durable independent electric motors in each wheel , headline this substantial investment by Komatsu to provide a complete
Bell ’ s move to underground
There were some interesting updates from South African-headquartered global ADT major Bell Equipment , in its 2021 year end results . It says its two new low profile ADT models for underground mining – launched at the end of 2021 , are penetrating this market segment well .
Both models feature an ‘ autonomous ready ’ platform that is easily configurable for remote operation . Given this success , the group expects to play a larger role in underground mining going forward . Machines have been deployed in Zambia and Tanzania , among other countries , where , similarly , they are performing well .
The new series Side Mount Cab ( SMC ) low profile underground trucks , referred to as Underground Articulated Dump Trucks ( ADTs ), were developed over several years by Bell Equipment , with the two models being the 30 t class B30L SMC and the 35 t class B35L SMC . Both models have a Stage IIIA Mercedes Benz OM471LA engine , Allison 4500 ORS transmissions and 40 t Kessler axles . Emphasised are the high performance engine with increased power and torque and long service intervals .
The Bell underground ADTs are available worldwide . In South Africa , Bell also has a distribution agreement with Aard Mining Equipment which is selling the two truck models under its own branding .
Bell Equipment ' s B35L SMC underground truck service solution to miners and contractors , it said .
“ Providing hard-rock miners with reliable underground loaders is part of a broader understanding of the need to assist their overall productivity in the face of global competition ,” Joshua Foale , Product Manager Mining , Komatsu Australia , said .
The hybrid Komatsu WX22H and WX18H LHDs each claim to have the lowest total operating costs in their class . Meanwhile , Komatsu ’ s analysis shows the conventionally powered Komatsu WX07 7 t loader is 14 % more productive than any other machine in its category . The WX04 4 t LHD offers 20 % more breakout force in its class , based on published information .
Komatsu ’ s WX22H and smaller WX18H achieve up to 20 % increase in tonnes moved , compared with conventionally powered loaders , the OEM said . They also have an up to 20 % decrease in fuel costs , based on operating trials . An independent life cycle analysis identified a 30 % reduction in operating costs , compared with their conventionally powered counterparts .
Improved work cycle performance is achieved by use of high efficiency electric traction motors in each wheel , making conventional mechanical power drive redundant , resulting in substantial reductions in operating costs , Komatsu said .
The Kinetic Energy Storage System ( KESS ) is at the heart of the switched reluctance hybrid drive , which captures and reuses braking energy from each of the four wheels . Heat-energy generated when the machine stops abruptly at the dig face is captured by the bi-directional KESS loop instead of being lost to the atmosphere .
KESS stores and releases 3 MJ of energy , supplementing power from the conventional diesel engine for greater acceleration to maximise cycle performance , according to the company .
A smart traction system provides smoother acceleration and results in less tyre wear and component degradation . It generates less inertia at each stop , significantly reducing potential damage to the drive train . Fewer underground emissions , lower heat rejection and greater operator comfort are all intended benefits of the hybrid system .
Komatsu ’ s 22 t WX22H produces 320 kW , with the smaller WX18H producing 280 kW . Both engines are rated to the strictest EU Stage V requirements for emission control , and both use the same KESS , capable of delivering 410 kW , effectively doubling power delivery on demand . A Joy 22HD hybrid LHD using SR drive and KESS has previously been tested at OZ Minerals ’ Prominent Hill copper-gold mine in South Australia , in addition to Codelco ’ s El Teniente underground mine in Chile .
34 International Mining | JUNE 2022