The selection of the best ore transportation system in underground mining presents a significant issue as this affects performance and economic viability. The two common types of these systems include rail haulage and truck haulage. In rail haulage, locomotives are used to transport large quantities of ore via fixed rails over long distances while, in truck haulage, trackless rubber-tired trucks are utilized to transport materials through ramps from stopes (Hou et al., 2022). Selecting either of these systems entails carrying out a careful evaluation regarding cost and other factors.
In terms of economics, the cost of the infrastructure required in the construction of rail haulage system is relatively high since the system requires tracks and underground crushers among other equipment. Consequently, it does not make economical sense to invest in such systems for small-scale projects because the investment cannot be easily recovered (Bąk et al., 2024). Truck haulage presents a cheaper investment option. In situations where expansion of underground facilities is economically unviable, investing in a truck fleet becomes a good idea (Greberg et al., 2016).
The level of operational flexibility is one of the main distinguishing features of these technologies. The use of trackless trucks allows more flexibility, which makes it possible for trucks to move along different slopes, turns, and gradients. It allows adjusting the truck fleet according to changing production needs on a daily basis (Hou et al., 2022). On the other hand, the rigidity of routes makes rail haulage less flexible. Nevertheless, in case of large and continuous production, the capacity will be better with rail haulage and lower mechanical wear will be expected during the mine’s lifetime.
In recent years, ventilation needs play a greater role in choosing the appropriate mode of haulage in underground mining. Hauling with the help of diesel trucks causes a lot of pollution because of the produced exhaust gases, mainly hydrocarbons and nitrogen oxide (Kowalski & Waszkowski, 2021). To prevent this type of pollution, the mining firms should use more funds to install and maintain ventilation systems, increasing costs of operations. On the other hand, the trains create little exhaust pollution because of electrically powered engines.
The complex nature of the mining logistics calls for an assessment strategy that requires multiple criteria analyses and simulations. The discrete-event simulation is frequently used for quantitative analysis of the conceptually designed transport systems throughout the lifetime of the mine (Greberg et al., 2016). The computer models analyze important parameters, including the match of trucks and loaders, efficiency of cycles, and the levels of emissions, ensuring the selection of a haulage system that will be most productive and environmentally efficient (Hou et al., 2022; Kowalski & Waszkowski, 2021).
The decision about which haulage system to use – truck or rail – should not follow the application of a universal principle but rather result from an elaborate case-based analysis. Generally, trucks are recommended for situations that demand flexible and complex haulage and do not require substantial investments. In contrast, rails are considered more efficient for bulk and long-distance haulage when the reduced cost of ventilation can compensate for the initial high expenses.
References
Bąk, P., Turek, M. C., Bednarczyk, Ł., & Jonek-Kowalska, I. (2024). The optimal transportation option in an underground hard coal mine: A multi-criteria cost analysis. Resources, 13(1), 14. https://doi.org/10.3390/resources13010014
Greberg, J., Salama, A., Gustafson, A., & Skawina, B. (2016). Alternative process flow for underground mining operations: Analysis of conceptual transport methods using discrete event simulation. Minerals, 6(3), 65. https://doi.org/10.3390/min6030065
Hou, J., Li, G., Chen, L., Wang, H., & Hu, N. (2022). Optimization of truck–loader matching based on a simulation method for underground mines. Sustainability, 15(1), 216. https://doi.org/10.3390/su15010216
Kowalski, A., & Waszkowski, R. (2021). Method of selecting the means of transport of the winning, taking into account environmental aspects. Applied Sciences, 11(12), 5512. https://doi.org/10.3390/app11125512
