Minimization of the deviation from the optimal cut-off grades in long-term production scheduling of open pit mines by using mixed integer programming

The basic objective of long-term production planning to takes measures for implementing to extractive cut-off grades and short-term production planning. So, the most important tool to implement the strategic and long-term program in open pit mines is extractive cut-off grades. Proposed methods show from not mentioning to exact regulation the extractive cut-off grade at various periods. In long-term production planning optimization, the extractive cut-off grades necessity is the correct management of the ore sending to plant processing. In this paper, exhibit linear programming model in order to sequence of mining blocks estimation from mentioning to control the extractive cut-off grades. Long-term production planning model using mixed integer mathematical programming is formulated. The purpose of the proposed model, minimization the deviation extractive grades in planning terms. Which this major be careful the case setting the extractive grades in each time period based on an accepted grade of plant. In order to the validity of result modeling, Chadormalou Iron Mine was chosen as the case study. The result shows the obtained extractive cut-off grades from proposed model generates the high accuracy of the average grade of the processing plant in each planning period. Also, all available operational constraints have been satisfied