Electrification of Large Open-Pit Copper Mines

The transportation problem of a large strip mine involves the loading, hauling, and dumping of both ore and waste. These materials are loaded with large electric shovels operating on benches along the slope of a hill or pit. The ore is transported over main-line tracks to the reduction plant, while the waste is hauled to suitable dumps. All main-line tracks are permanent and are equipped with permanent overhead distribution systems (Figure 1). All bench and dump tracks are portable and are equipped with portable overhead distribution systems. Sixty per cent of the world's copper is now obtained by open-pit mining of low-grade ore. Electrification of haulageways for open-pit mining is keeping pace with the expansion and is modernizing the transportation of huge tonnages. Huge capacities necessitating heavy cars and heavy grades demanding short-period overloads have been responsible for the selection of the electric locomotive for motive power. From the standpoint of locomotive capacity, rail size, dump-car capacity, and density of traffic, most open-pit electrifications compare in size with our large steam-road installations and hold an important place in the field of heavy traction (Figure 2). In addition to describing the haulage problem of large open-pit copper mines, this paper discusses the design of permanent and portable distribution systems.