Shahrood University of Technology Journal of Mining and Environment 2251-8592 16 2 2025 04 01 Simultaneous Optimization of Mine Production Rate and Cut-off Grade using Particle Swarm Optimization 583 598 3308 10.22044/jme.2024.13943.2601 EN Javad Lotfi Godarzi Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran Ahmad Reza Sayadi Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran Amin Mousavi Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran Micah Nehring School of Mechanical and Mining Engineering, University of Queensland, Australia Journal Article 2023 12 08 The production rate and cut-off grade are two critical variables in the design and planning of open-pit mines. Generally, the production rate depends on the reserve amount, which is influenced by the cut-off grade. Additionally, the cut-off grade is affected by the production cost, which is influenced by the production rate and product price. A conventional approach optimizes each variable individually, and neglects the trade-off between production rate and cut-off grade, leading to a sub-optimal solution. This work aimed to address the simultaneous optimization of the production rate and cut-off grade and provided a novel solution for this problem. In this context, a non-linear mathematical model was developed. The Particle Swarm Optimization (PSO) algorithm was used due to the model's non-linear nature and the continuous decision variables. Implementing the model for a typical copper mine showed that the suggested model resulted in a concurrent optimization of production rate and cut-off grade. The maximum NPV of 1.153 billion dollars occurred at a production rate of 15.66 Mt/y, and a cut-off grade of 0.64%. Additionally, a sensitivity analysis was conducted for key factors such as product price, discount rate, and maximum capital cost. https://jme.shahroodut.ac.ir/article_3308_c68f1ab042b222c42a93ab0798f748af.pdf