A mathematical model for open pit mine production scheduling with Grade Engineering® and stockpiling

• Published in: International journal of mining science and technology Vol. 31; no. 4; pp. 717 - 728
• Main Authors: Fathollahzadeh, Karo, Mardaneh, Elham, Cigla, Mehmet, Asad, Mohammad Waqar Ali
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2021; Elsevier
• Subjects: Exact methods; Grade Engineering; Mine planning; Optimization; Scheduling; Stockpiling; Exact methods; Grade Engineering; Scheduling; Mine planning; Stockpiling; Optimization
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2021.03.011

This paper presents the development and implementation of an innovative mixed integer programming based mathematical model for an open pit mining operation with Grade Engineering framework. Grade Engineering comprises a range of coarse-separation based pre-processing techniques that separate the desirable (i.e. high-grade) and undesirable (i.e. low-grade or uneconomic) materials and ensure the delivery of only selected quantity of high quality (or high-grade) material to energy, water, and cost-intensive processing plant. The model maximizes the net present value under a range of operational and processing constraints. Given that the proposed model is computationally complex, the authors employ a data pre-processing procedure and then evaluate the performance of the model at several practical instances using computation time, optimality gap, and the net present value as valid measures. In addition, a comparison of the proposed and traditional (without Grade Engineering) models reflects that the proposed model outperforms the traditional formulation.