A conceptual framework for selection of the effective truck-shovel system for bulk material transport in open pit metal mines

Among the several bulk material transport and handling systems in large scale open pit metal mines, the truck/shovel system competes with overland conveyor belt system in providing minimum cost per tonne of the material transported. For high- volume long-distance travel, overland conveyor systems are proven to be cost- effective compared to truck-shovel systems. However, with effective design (selection and sizing) of the truck-shovel system, especially with the new development of large off-highway trucks of up to 400-ton capacity and shovels of up to 60 cubic metre bucket capacity, the truck-shovel system offers strong challenge to the overland conveyor belt systems. This is mostly due to its increased tare weight, its versatility and its potential to maintain a stable production rate even when few trucks are broken down. The objective of this research work is to develop a conceptual framework for design and selection of the effective truck- shovel system for transportation of bulk materials in open pit metal mines. Several areas of the truck/shovel system were studied. Data on equipment performance characteristics and pit operational conditions were collected over a 12-month period. These data were processed and analysed and construction of the various statistical and empirical models were undertaken. Analysis of these developed models indicated many aspects some of which deviated from their expected performances providing room for improvement of the existing truck/shovel system. The generated models have also provided key statistical distributions, whose cumulative distribution functions can be used for generating input data for each of the truck-shovel system activity or event that is taking place in an open pit.