Optimization of Working Bench Length of Inclined Composite Coal Seam Open-Pit Mine

In order to optimize the Working bench length of inclined composite coal seam open pit mine, Through theoretical analysis and calculation, the relationship between different mining technology working bench and working face transport costs was studied, The influence of the length of the working bench on the stripping ratio of production and the mining with discharging cost of the unit coal in the mining area were studied. Taking the minimum sum of the transportation cost of working face and the cost of mining and discharging of the unit coal as the goal, a mathematical model is established, which takes the working bench as independent variable,the corresponding function curve was obtained, Considering the macroscopic planning of open-pit mine, obtain an optimization method for the length of economical and reasonable working bench of inclined composite coal seam open pit mine on the basis of technical feasibility. A case study of Heishan opencast coal mine,the Results show that when the length of working bench of the 13-2 coal seam is 0.9km, the minimum annual cost of mining and discharging and the transportation cost of the open pit mine were the smallest, and the minimum value is 269 million yuan, Considering the actual pit-limit of Heishan open pit mine, it is concluded that the comprehensive optimum line length of 13-2 coal seam in Heishan open-pit mine is 1.0km.