Shigen-to-sozai, Vol.117, No11, pp.862-868.





Multi-Period Production Planning for Underground Cut-and-Fill associated with Operational Uncertainties





Qinghua CHENa, Jiro YAMATOMIb, Gento MOGIb and Tsuyoshi ADACHIb



a. Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
b. School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan



In order to deal with the uncertainties regarding ore grade estimations, production rates and metal prices during overall planning periods, a Chance-constrained programming combined with a dynamic programming was developed to incorporate these uncertainties. Four cases of the Chance-constrained programming formulation were proposed under different uncertainty assumptions of ore grades, production rates and metal prices. Simulations were conducted by taking the magnitude of the Chance-constraint and objective function violations into consideration. Simulation results with respect to the studied mine clarify that the increase of the confidence levels of Chance-constraints can lead to the decrease of NPV of the planning project, whereas the increase of the given probabilities of maximizing the allowable limit of the fluctuation of metal prices can lead to the increase of the NPV.

KEY WORDS: Cut-and-Fill, Optimization of Production Planning, Dynamic Programming (DP), Chance-constrained Programming, Operational Uncertainties