Abstract

Mining Plus was engaged by RailVeyor to complete a LOM cost trade-off study 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 the following scenarios:

• Mine depths of: 500, 750, 1000 and 1250m.
• Four different materials handling methods:
  • RailVeyor: Rail transportation consisting of a light rail track with side propultion units suitable for long haulage; it can be installed more quickly than a 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, can readily handle both waste and ore of different characteristics over the same system at the same time.
  • Diesel Truck: Truck haulage is widely used in underground operations for long distance hauling of production material from loading areas to shaft or directly to the surface.
  • BEV truck: Considered based on preliminary capital and operating costs
  • Conveyor: Common in high production rate mines transporting crushed material over a long distance.
  • Shaft: Common method hoisting mostly crushed material.
• Annual Production rates: 1Mtpa – 2Mtpa - 5Mtpa - 10Mtpa - 15Mtpa – 20Mtpa.

All scenarios were modelled over a 20 year mine life at the designated production rate.

The modelling includes 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
• Dump time.

The RailVeyor and conveyor modelling considers gradients of 1:7 and 1:5.5 with and without a dedicated decline.

The trade off model has been built considering:

• Capital Cost:
  • Purchase price.
  • Interest/depreciation/Insurance/life.
• Operating Cost: the unit rate calculations, used to work out the cost per tonne based on first principle calculations including:
  • Consumables: fuel burn of power usage.
  • Equipment ownership: loader/truck.
  • Equipment Maintenance: components.
  • Labor: 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.

A sample of initial results are demonstrated below:

1mtpa 500m

1mtpa 1250m

10mtpa 500m

10mtpa 1250m

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.