UNDERGROUND RAIL
Staying on track
Uniquely , the Kazzinc Dolinny Railveyor system has three dump loops to unload ore at surface
Paul Moore reviews the latest developments in lithium battery locomotives for underground mine haulage as well as other railbased bulk handling technology progress for subsurface mines
Looking first at innovations , Railveyor from Rail-Veyor Technologies Global Inc is a fully electric and autonomous mining bulk material handling system combining a narrow gauge light rail system with U-shaped steel cars , propelled by low-horsepower stationary power plants adjacent to the rail route . It can be installed more quickly than conventional rail , can operate at steep gradients , is quick to install due to its low weight per metre of rail requiring limited site preparation , is electrified without the requirement for overhed wires or battery storage , and can readily handle both waste and ore of different characteristics over the same system at the same time .
The system until recently had three large active underground installations – at Agnico Eagle ’ s Goldex mine in Quebec , Canada ( 3 km long , 600 t / h , 17.5 % grade ) and Doe Run ’ s Missouri , USA lead mines ( 5.5 km , 174 t / h ). Now , a third , 3.8 km , 300 t / h system , for which the order was first announced in 2020 , is in commissioning at Kazzinc ’ s Dolinny mining operations in Ridder , Eastern Kazakhstan . The mainly underground system moves gold ore from the mine to any of three different stockpiles located on the surface . The Dolinny system uses Komatsu Joy feeders to load five trains which will work around the clock running autonomously at a speed of 3 m / s . There are three dump loops to unload ore at surface which is unique as the similar systems in other locations have only one dump loop .
Other contracts signed by Railveyor of late include for the Frunze iron ore mine in Ukraine , which has been delayed due to the ongoing conflict . The technology is also being named in many more scoping studies , technical reports and pre-feasibility studies , a good example being the First Quantum Minerals Technical Report for Cobre Las Cruces mine in Spain , released in January 2022 which states : “ Processing of PPS
[ Polymetallic Primary Sulphide ] is based on comprehensive laboratory and pilot plant test work results carried out between 2014 and 2018 . PPS feed to the plant stockpile will be sourced from underground operations via an electrical Railveyor system .”
The trade-off between Railveyor and other bulk materials handling was recently considered in a new study by Mining Plus to compare capital and operating costs for the Railveyor against conventional materials handling methods over a range of scenarios including depth , production rate and mine life . The trade off model was built to consider mine depths of : 500 , 750 , 1,000 and 1,250 m . Four different materials handling methods were included – along with Railveyor namely diesel truck haulage , widely used in underground operations for long distance hauling of production material from loading areas to shaft or directly to the surface ( including BEV trucks consideration based on preliminary capital and operating costs ; conveyors which are common in high production rate mines transporting crushed material over a long distance and shaft hoisting mainly used for crushed material . Annual Production rates of 1Mt / y ,/ 2 Mt / y , 5 Mt / y , 10 Mt / y , 15 Mt / y , 20 Mt / y were included and all scenarios were modelled over a 20 year mine life at the designated production rate . The modelling included the costs for handling the material from the development face or stope to the materials handling system to consider the different material flow paths . The loader productivity has also been considered for the different scenarios considering loading time at drawpoint ; travel time over different distances ; overall operating efficiency ; and dump time . The Railveyor and conveyor modelling considers gradients of 8 ° and 10 ° with and without a dedicated decline .
The trade off model has been built considering capital cost including purchase price , interest / depreciation / insurance / life , and operating cost where the unit rate calculations , used to work out the cost per tonne based on first principle calculations included consumables : fuel burn of power usage ; equipment ownership : loader / truck ; equipment maintenance : components and labour : equipment operator , maintenance , supervision .
The trade off model bas been configured to input a transport rate and to be able to graph each transport option on one graph for a given scenario over a 20 year mine life . Initial results indicate that the Railveyor offers significant transport cost savings in all bar the shortest operating periods in shallow mines and low production rates . The model has been set up to allow for most parameters to be adjusted and sensitivities to power , diesel cost , labour etc to be considered . BEV transport has been considered at a preliminary stage considering the early stage of maturity of this transport method .
Specifically , for a mine life of > 2.5 years at any production rate , Railveyor ( steep installation with 10 °, or 18 % slope ) proves to be most costeffective solution . The Railveyor installation in standard gradient declines ( 8 ° or 14 %) is still a close-contending options . Conveyor and shaft material handling methods are cited in the study to be the least viable option .
Ferrit working on lithium battery loco solutions
In its drive to create more sustainable machinery with autonomous solutions for the global mining industry , Czech company Ferrit ’ s R & D department is working hard to introduce their own lithium battery for electric locomotive drives for 2022 . This new battery is being designed to be used in
10 International Mining | JUNE 2022