Simultaneous Optimization of Final Pit and Production Schedule in Open-Pit Coal Mines

A dynamic sequencing method has been developed that can simultaneously optimize the final pit and the production schedule of an open-pit coal mine. The method first establishes a geological seam model of a bedded coal deposit which estimates the relevant attributes of coal seams at the center of each block on the X-Y plane. Based on the seam model, a sequence of “geologically optimum final pits” is generated and, in each of these pits, a sequence of “geologically optimum push-backs” is generated. The geologically optimum push-backs are then put into a dynamic programming scheme and the best production schedule which has the highest NPV is obtained for each final pit. After the best production schedules for all the final pits are obtained, the one with the highest overall NPV is the optimum final pit and its associated best schedule is the overall best production schedule.

A Push-Back Sequencing Model for Production Planning in Open-Pit Coal Mining

A dynamic sequencing method has been developed to simultaneously optimize the coal production rate, waste stripping rate, mining sequence, and mine life of an open-pit coal mine. The method first establishes a geological seam model of a bedded coal deposit which estimates the relevant attributes of coal seams at the center of each block on the X-Y plane. Based on the seam model, a sequence of “geologically optimum push-backs” is generated in the final pit. The geologically optimum push-backs are then put into a dynamic sequencing model and economically evaluated. The best production schedule which has the highest NPV is obtained, which indicates the best quantities of coal and waste to be mined in each year, the best zone to be mined in each year, and the best number of years to mine the entire final pit.