ANALYSIS OF A MINE-MILL PRODUCTION SYSTEM USING SIMULATION AND INTEGER PROGRAMMING

Abstract

Mine-mill production faces several operational difficulties, such as fluctuations in ore delivery from mines, random failure of machines, usage of stockpiles and storage bins, and changeover time when switching products. This study was initiated at a particular Canadian mining company. However, changes in the economic condition in the mining industry during 2008 have meant that circumstances have changed to the extent that this work should be seen as an illustration of methods rather than a study of the specific situation at the mining company. This mining company will remain unnamed throughout this thesis. The purpose of this research is to develop a series of production campaigns, each of which uses a specific draw scheme to coordinate the receiving of ore, maintenance planning and product scheduling. The approach includes a combination of mathematical programming model and a simulation model. The solution from the integer programming model is a set of campaigns that minimize the inventory levels of unprocessed ore, the number of days on shutdown, and the number of active piles required at any point in time. The simulation model uses this solution as its production scheduling input with integrated stochastic elements to evaluate mill system performance. In this thesis, the formulation of the mathematical programming model and construction of the simulation model, as well as the maintenance data analysis used as stochastic element of the model is discussed.