Qualificação de doutorado do discente Natanael Salgado dia 08/09 as 08:30.

Qualificação de doutorado do discente Natanael Salgado dia 08/09 as 08:30.

Título: Single- and multi-objective simheuristic algorithms to deal with ore grade uncertainties in open-pit mines

Resumo: This study introduces innovative methods for optimizing ore blending planning and the green shovel allocation problem in open-pit mines, considering uncertainties in ore grades present in stockpiles and mining fronts. Initially, we introduced a mixed-integer linear programming model (MILP) to represent the problem. To address the uncertainties of the problem, we propose a simheuristic algorithm, named SIM-Math-ILS, which combines a MILP-based formulation, a Monte Carlo Simulation (MCS) procedure, and the Iterated Local Search (ILS) metaheuristic. This MILP formulation solves the shovel allocation subproblem, the MSC procedure emulates uncertainties in ore grades, and the ILS treats the ore blending planning. The ILS incorporates a greedy constructive procedure to generate good quality initial solutions, five neighborhood structures to explore the solution space of the problem, a local search procedure, called Pipe-RVND, for refining the solutions, and a perturbation procedure to prevent the search from getting stuck in a local optimum. We evaluated the proposed algorithm in 10 real instances of an open-pit copper mine. Initially, we showed that this algorithm found solutions close to the optima in all instances of the deterministic version of the problem. Concerning the stochastic version of the problem, the proposed algorithm demonstrated its ability to handle uncertainties at various levels, producing more robust solutions in all evaluated instances. As future work, we intend to implement a simheuristic multi-objective algorithm based on the multi-objective variable neighborhood search with the objectives of minimizing deviations in ore quality from targets and fuel consumption.

Banca: Prof. Dr. Luciano Perdigão Cota (orientador), Prof. Dr. Marcone Jamilson Freitas Souza (coorientador), Prof. Dr. Gustavo Pessin (coorientador), Prof. Dr. Puca Huachi Vaz Penna, Prof. Dr. Gustavo Campos Menezes

Link: meet.google.com/kju-qbve-cxg

Data: 08/09/2025
Horário: 08:30