Planification strategique d'une mine souterraine avec teneur de coupure variable

Strategic planning of an underground mine is a complex activity that requires several steps. This level of planning defines the strategy of the company for the next years. The planning horizon is relatively long but it depends on the resources and reserves of the mine. During the scheduling of an underground mine, several aspects must be evaluated such as the start and the end of the mine, the production rate, the cut-off grade, etc.. When several mines can begin at the same time and are using the same human and material resources, the difficulty of the problem increases. Under these conditions, it is hard to get a good solution quickly with manual methods. The cut-off grade is also a strategic decision and is closely related to planning. It is therefore necessary to incorporate this decision into the strategic plan. Once again, the complexity increases as the duration of the work is related to the content of selected cut-off grade.;Strategic planning for open pit mining is well documented but the application of the operational research in underground is newer. In this paper, a mixed integer program (MIP) is proposed to solve a problem of strategic planning of an underground mine. The model is specifically developed for Raglan Mine in northern Quebec. The model will serve as a tool for decision support for the Raglan Mine's engineers. Raglan Mine has four mines in operation and several potential mining projects. It becomes difficult to determine when a project must start. Using the model, several scenarios can be tested. It should be noted that the model is general and can be easily modified to fit with other mines.;This master thesis can be divided into two main themes: the parameters evaluation and mathematical model. The parameters evaluation is important because many steps must be performed before the planning. Normally, the design must be done before the planning. In this paper, the design for a new mine is evaluated by statistical curves. This method can get a solution to the design criteria established in the past. If a real design is made, the activities can be added to the model to get a better estimate of the mine profit. Once the parameters evaluated, the model is used to define the optimal schedule and the best cut-off grade. The current theory of the cut-off grade is difficult to apply in the context of Raglan Mine. In fact, each deposite at Raglan Mine has is own grade-tonnage curve. The choice of cut-off is made by the model that allows each deposite to have its own cut-off grade.