BATTERY AND ELECTRIC MACHINES
“ We have different size-class machines for SmartDrive in the pipeline as well , but if a customer wants some of our current dieselpowered applications with battery-electric SmartDrive architecture , we can potentially develop it even if it is not in the planned pipeline ,” she said .
“ It ’ s actually quite an efficient process to implement our modular battery-electric architecture in different machine types .”
Looking to future machines , Mykkänen , like others in mining ’ s battery-electric industry , pointed to developments in battery energy density as a game changer .
He said : “ On our machines , the batteries are pretty big , and the chemistry is really safe , but , in the future , can we perhaps get a higher capacity battery in the same footprint ?
“ The battery we are using is enough and works great on its own in process equipment such as explosives chargers and lifting and installation equipment , as they can be charged from the mine grid during operation . For transportation , logistics and other applications with long tramming distances , we provide fast charging units ( the CT40 and CC150 chargers ) to ensure operational efficiency . With fast charging units , batteries can be charged full in half an hour , during a break or , for example , during concrete dispatching .”
Koivisto concluded : “ However , more capacity in the same size footprint as current batteries would be a positive development .”
Going green
GHH Group , comprising GHH Fahrzeuge , GHH Mining Machines and Mine Master , says it is constantly supporting the industry drive towards reducing emissions and ventilation requirements , while improving performance and efficiency .
GHH Fahrzeuge has recently developed a tethered battery-electric loader predominantly for soft-rock applications . The LF-19EB is specifically designed for flexible loading into a feeder breaker . It reduces the loss in productivity that typically comes with having to tow a tethered machine between production ends by using an on-board battery that allows operators to easily relocate the machine regardless of mine power infrastructure .
The LF-19EB has a 19-t payload capacity with a tractive effort force of 380 kN and an average of 250 kVA power under permanent load and 315 kVA peak . It comes with a maximum cable length of 250 m .
With a high payload and low height , the machine is designed to operate at a maximum grade of 28 %, a 15 % slope and a maximum temperature of 52 ° C , the company says .
“ This loader is a perfect intermediate between tethered-electric and a pure battery solution – more flexible than a tethered loader and less risky than a pure battery loader , based on wanting a full shift operation on one charge ,” GHH says .
In addition to this electric LHD , GHH Group has been working on various battery-electric product solutions for the industry .
Mine Master recently added to its portfolio of underground mining machines with a batterypowered electric bolter , which is already undergoing testing .
Jerzy Nadolny , Mine Master CEO , said : “ With new developments , we work closely with KGHM , one of the world ’ s biggest copper producers . The design of the electric machine was a response to the needs of this customer .
“ The mines are going deeper , so the cost of ventilation is increasing with every metre . Battery-electric solutions will help to reduce gas emissions , improve safety and ease maintenance requirements .”
The Roof Master 1.8KE is undergoing testing at KGHM ’ s Lubin mine in Poland , with the first comments from mine operators enthusiastic : “ During the driving process , the machine is very quiet , the engine is hardly audible ,” Karol Ignatowicz from Lubin mine said . “ I am impressed , the cabin is very comfortable ; so far everything works well .”
The machine is designed to work in galleries from 2 m up to 5.8 m in height , and it is equipped with a 1.8 m mechanised bolting mast for nine bolts .
The battery installed on board is a 120 kWh , sodium-nickel system , which is intrinsically maintenance-free and comes with a long life , high reliability and an enclosure with good thermal insulation , the company says . The battery cells are hermetically sealed and enclosed in a metallic box , making exposure to hazardous and flammable materials highly improbable .
GHH ’ s LF-19EB tethered battery-electric LHD is specifically designed for offering flexible loading into a feeder breaker
Said battery can be recharged without any special equipment by using an existing mine power network in the 500-1,000 V range . For this purpose , a battery charger is built onto the machine chassis . At the same time , regenerative braking allows the battery to recharge when the rig is tramming downhill .
All of this means cycle times are not disrupted and the machine has increased working time compared with the diesel-powered equivalent that requires refuelling .
The RM1.8KE will recharge once a week during non-working time to reach full capacity , Mine Master claims .
The company added : “ Overall , the Mine Master battery-powered machine has a far higher efficiency than the diesel equivalent , so the effective energy put into the mining network is far better utilised than it is with diesel energy .
“ The true benefit of battery technology comes in the total cost of ownership reduction per meter advanced , taking not only the machines but also the services supply into account .”
The machine is equipped with an ergonomically designed , closed , air-conditioned operator cabin to add to the benefits of an already quieter , emission-free operation , Mine Master says .
The Roof Master 1.8KE is undergoing testing at KGHM ’ s Lubin mine in Poland
16 International Mining | MARCH 2021