Multi-Objective Optimization of In-Pit Crushing and Conveying Systems Considering Slope Stability: A Case Study of the Beskuduk Coal Mine

Due to the occurrence of inclined coal seams and the formation of weak layers in the floor of the Beeskuduk open-pit coal mine, this study focuses on the multi-objective optimization of crusher station relocation and belt conveyor layout. In terms of research methodology, the relocation cost compensation method and the minimum cost method were used to establish a crusher station relocation model. The reduction method in FLAC3D was employed to conduct the numerical simulation, and a comprehensive three-dimensional evaluation framework based on “Technological feasibility, safety performance, and economic efficiency” was established. The Analytic Hierarchy Process (AHP) was employed to determine the weights of each indicator, and the multi-objective Pareto optimization was achieved by integrating the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The results show that the optimal relocation step distance of the crushing station is 880 m and the optimal relocation site is at the +1120 level. For the belt conveyor, Scheme 2 is preferred, which involves elevating the conveyor from the +1115 level to the +1308 level. The safety and stability coefficient of Scheme 2 reaches 1.758, which is 8.3% and 1.4% higher than that of Scheme 1 and Scheme 3. Moreover, the TOPSIS closeness degree of Scheme 2 reaches 0.892, making it the Pareto optimal solution. This research provides a scientific framework for the optimization of the in-pit crushing and conveying (IPCC) system in open-pit mines under complex geological conditions, offering valuable insights for the efficient and safe mining of similar inclined coal seams in open-pit mines.