A model of discounted profit variation of open pit production sequencing optimization

This paper offers a solution of the production sequencing optimization of an open pit mine through the investigation of the time aspect of the problem. The solution is obtained with the use of the author’s method of production scheduling optimization with multi-stage stabilization of the mining rate and incorporation of a combinatorial analysis for generating all theoretically possible variants of the mine sequence arrangement. The optimization scheduling model is based on the concept of “mine-mill-market” interaction and implements the mine planning principles of metal recovery optimization and waste deferment. The theoretical framework of the production sequencing optimization is described in the context of using the cumulative spatial and time graphs of an open pit mine. The results obtained from the production sequencing optimization of a hypothetical open pit gold mine indicate a discrete model of the discounted profit variation which reveals the great potential of the solution as a tool for solving the problem of price volatility and geological uncertainty in short- and long-term plan. A program written in C++ and incorporating the ILOG CPLEX Callable Libraries is used for running the production scheduling optimization model