a generalized mathematical model for integrated production planning in drift-and-fill mining operation

Drift-and-fill mining is a variation of cut-and-fill mining method. drift-and-fill mining method refers to the excavation of several parallel drifts in ore. excavation of a new drift could start when its adjacent drifts are backfilled or not excavated. the amount of ore material and its grade depends on the excavation sequence of drifts. as the number of drifts increases, one will need a model to optimize the drift excavation and backfilling sequence. this paper introduces a mathematical model to determine the optimal drift-and-fill sequence while the safety constraints, excavation, and backfilling capacities and their dependencies are satisfied. the model seeks to minimize the deviations from some predefined goals, and it handles the long-term and short-term constraints in separate and integrated scenarios. an application of the model is presented based on the data available from a lead/zinc underground mining project. there are 91 drifts in the selected level. based on the monthly planning horizon, the integrated model leads to the slightest deviations in both the mining rate and average grade, and the deviation from the predetermined annual goals is negligible. for the case where long-term and short-term plans are determined separately, the deviation is approximately 10%.